Update README.md

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2017-2019 Étienne "Reuh" Fildadut
+Copyright (c) 2017-2021 Étienne "Reuh" Fildadut
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -1,24 +1,31 @@
 Candran
 =======
-Candran is a dialect of the [Lua 5.3](http://www.lua.org) programming language which compiles to Lua 5.3, LuaJIT and Lua 5.1 compatible code. It adds several useful syntax additions which aims to make Lua faster and easier to write, and a simple preprocessor.
+Candran is a dialect of the [Lua 5.4](http://www.lua.org) programming language which compiles to Lua 5.4, Lua 5.3, Lua 5.2, LuaJIT and Lua 5.1 compatible code. It adds several useful syntax additions which aims to make Lua faster and easier to write, and a simple preprocessor.
 
 Unlike Moonscript, Candran tries to stay close to the Lua syntax, and existing Lua code should be able to run on Candran unmodified.
 
 ````lua
 #import("lib.thing") -- static import
-#local debug or= false
+#local DEBUG = false
+
+#if DEBUG then
+#	define("log(...)", "print(...)") -- macro: calls to log() will be replaced with print() in compiled code
+#else
+#	define("log(...)", "") -- remove calls to log from the compiled code when DEBUG is true
+#end
+log("example macro") -- preprocessor macros
 
 local function calculate(toadd=25) -- default parameters
 	local result = thing.do()
 	result += toadd
-	#if debug then -- preprocessor conditionals
+	#if DEBUG then -- preprocessor conditionals
 		print("Did something")
 	#end
 	return result
 end
 
 let a = {
-	hey = true,
+	hey = 5 // 2, -- Lua 5.3+ syntax, that will be translated to work with the current Lua version
 
 	child = nil,
 
@@ -31,6 +38,8 @@ let a = {
 	end
 }
 
+const five = 5 -- shortcut for Lua 5.4 attributes 
+
 a:method(42, (foo)
 	return "something " .. foo
 end)
@@ -72,19 +81,23 @@ end
 Candran is released under the MIT License (see ```LICENSE``` for details).
 
 #### Quick setup
-Install Candran automatically using LuaRocks: ```sudo luarocks install rockspec/candran-0.12.0-1.rockspec```.
+Install Candran automatically using LuaRocks: ```sudo luarocks install candran```.
 
-Or manually install LPegLabel (```luarocks install lpeglabel```, version 1.5 or above), download this repository and use Candran through the scripts in ```bin/``` or use it as a library with the self-contained ```candran.lua```.
+Or manually install LPegLabel and argparse (```luarocks install lpeglabel```, version 1.5 or above, and ```luarocks install argparse```, version 0.7 or above), download this repository and use Candran through the scripts in ```bin/``` or use it as a library with the self-contained ```candran.lua```.
 
 You can optionally install lua-linenoise (```luarocks install linenoise```, version 0.9 or above) for an improved REPL, and luacheck (```luarocks install luacheck```, version 0.23.0 or above) to be able to use ```cancheck```. Installing Candran using LuaRocks will install linenoise and luacheck by default.
 
 You can register the Candran package searcher in your main Lua file (`require("candran").setup()`) and any subsequent `require` call in your project will automatically search for Candran modules.
 
+If you use LÖVE, some integration with Candran is detailled [here](https://github.com/Reuh/candran/wiki/L%C3%96VE).
+
 #### Editor support
 Most editors should be able to use their existing Lua support for Candran code. If you want full support for the additional syntax in your editor:
 * **Sublime Text 3**:
 	* [sublime-candran](https://github.com/Reuh/sublime-candran) support the full Candran syntax
-	* [SublimeLinter-candran-contrib](https://github.com/Reuh/SublimeLinter-contrib-candran) SublimeLinter plugin for Candran
+	* [SublimeLinter-cancheck-contrib](https://github.com/Reuh/SublimeLinter-contrib-cancheck) SublimeLinter plugin for Candran using ```cancheck```
+	* [SublimeLinter-candran-contrib](https://github.com/Reuh/SublimeLinter-contrib-candran) SublimeLinter plugin for Candran using ```canc -parse``` (only checks for syntaxic errors, no linting)
+* **VS Code**: [vscode-candran](https://github.com/Reuh/vscode-candran) basic support for the Candran syntax
 * **Atom**: [language-candran](https://atom.io/packages/language-candran) support the full Candran syntax
 
 For linting, if your editor support [luacheck](https://github.com/luarocks/luacheck), you should be able to replace it with ```cancheck``` (in this repository ```bin/cancheck```, or installed automatically if Candran was installed using LuaRocks), which is a wrapper around luacheck that monkey-patch it to support Candran.
@@ -92,7 +105,7 @@ For linting, if your editor support [luacheck](https://github.com/luarocks/luach
 The language
 ------------
 ### Syntax additions
-After the preprocessor is run the Candran code is compiled to Lua. Candran code adds the folowing syntax to Lua:
+After the [preprocessor](#preprocessor) is run the Candran code is compiled to Lua. Candran code adds the folowing syntax to Lua 5.4 syntax:
 
 ##### Assignment operators
 * ````var += nb````
@@ -171,8 +184,20 @@ let a = {
 
 Similar to ```local```, but the variable will be declared *before* the assignemnt (i.e. it will compile into ```local a; a = value```), so you can access it from functions defined in the value.
 
+This does not support Lua 5.4 attributes.
+
 Can also be used as a shorter name for ```local```.
 
+##### `const` and `close` variable declaration
+```lua
+const a = 5
+close b = {}
+
+const x, y, z = 1, 2, 3 -- every variable will be defined using <const>
+```
+
+Shortcut to Lua 5.4 variable attribute. Do not behave like `let`, as attributes require the variable to be constant and therefore can't be predeclared. Only compatibel with Lua 5.4 target.
+
 ##### `continue` keyword
 ```lua
 for i=1, 10 do
@@ -424,30 +449,76 @@ Will output ````print("Bonjour")```` or ````print("Hello")```` depending of the
 
 The preprocessor has access to the following variables:
 * ````candran````: the Candran library table.
-* ````output````: the current preprocessor output string. Can be redefined at any time.
-* ````import(module[, [options])````: a function which import a module. This should be equivalent to using _require(module)_ in the Candran code, except the module will be embedded in the current file. _options_ is an optional preprocessor arguments table for the imported module (current preprocessor arguments will be inherited). Options specific to this function: ```loadLocal``` (default ```true```): ```true``` to automatically load the module into a local variable (i.e. ```local thing = require("module.thing")```); ```loadPackage``` (default ```true```): ```true``` to automatically load the module into the loaded packages table (so it will be available for following ```require("module")``` calls).
+* ````output````: the current preprocessor output string. Can be redefined at any time. If you want to write something in the preprocessor output, it is preferred to use `write(...)` instead of directly modifying `output`.
+* ````import(module[, [options])````: a function which import a module. This should be equivalent to using _require(module)_ in the Candran code, except the module will be embedded in the current file. Macros and preprocessor constants defined in the imported file (using `define` and `set`) will be made available in the current file. _options_ is an optional preprocessor arguments table for the imported module (current preprocessor arguments will be inherited). Options specific to this function:
+	* ```loadLocal``` (default ```true```): ```true``` to automatically load the module into a local variable (i.e. ```local thing = require("module.thing")```)
+	* ```loadPackage``` (default ```true```): ```true``` to automatically load the module into the loaded packages table (so it will be available for following ```require("module")``` calls).
 * ````include(filename)````: a function which copy the contents of the file _filename_ to the output.
 * ````write(...)````: write to the preprocessor output. For example, ````#write("hello()")```` will output ````hello()```` in the final file.
 * ```placeholder(name)```: if the variable _name_ is defined in the preprocessor environement, its content will be inserted here.
-* ````...````: each arguments passed to the preprocessor is directly available in the environment.
+* ```define(identifier, replacement)```: define a macro. See below.
+* ```set(identifier, value)```: set a preprocessor constant.
+* each arguments passed to the preprocessor is directly available in the environment.
 * and every standard Lua library.
 
+#### Macros
+
+Using `define(identifier, replacement)` in the preprocessor, you can define macros. `identifier` is expected to be string containing Candran/Lua code (representing either a identifier or a function call), and `replacement` can be either a string containing Candran/Lua code or a function.
+
+There are two types of macros identifiers: variables, which replace every instance of the given identifier with the replacement; and functions, which will replace every call to this function with the replacement, also replacing its arguments. The `...` will be replaced with every remaining argument. Macros can not be recursive.
+
+If `replacement` is a string, the macro will be replaced with this string, replacing the macros arguments in the string. If `replacement` is a function, the function will be called every time the macro is encoutered, with the macro arguments passed as strings, and is expected to return a string that will be used as a replacement.
+
+If `replacement` is the empty empty, the macro will simply be removed from the compiled code.
+
+```lua
+-- Variable macro
+#define("x", 42)
+print(x) -- 42
+
+-- Function macros
+#define("f(x)", "print(x)")
+f(42) -- replaced with print(42)
+
+#define("log(s, ...)", "print(s..": ", ...)")
+log("network", "error") -- network: error
+
+#define("debug()", "")
+debug() -- not present in complied code
+
+#define("_assert(what, err)", function(what, err)
+#	return "if "..what.." then error("..err..") end"
+#end)
+_assert(5 = 2, "failed") -- replaced with if 5 = 2 then error("failed") end
+```
+
+Candran provide some predefined macros by default:
+* `__STR__(expr)`: returns a string litteral representing the expression (e.g., `__STR__(5 + 2)` expands to `"5 + 2"`)
+* `__CONSTEXPR__(expr)`: calculate the result of the expression in the preprocessor, and returns a representation of the returned value, i.e. precalculate an expression at compile time
+You can disable these built-in macros using the `builtInMacros` compiler option.
+
 Compile targets
 ---------------
-Candran is based on the Lua 5.3 syntax, but can be compiled to Lua 5.3, LuaJIT, and Lua 5.1 compatible code.
+Candran is based on the Lua 5.4 syntax, but can be compiled to Lua 5.4, Lua 5.3, Lua 5.2, LuaJIT, and Lua 5.1 compatible code.
 
-To chose a compile target, set the ```target``` option to ```lua53```, ```luajit```, or ```lua51``` in the option table when using the library or the command line tools. Candran will try to detect the currently used Lua version and use it as the default target.
+To chose a compile target, set the ```target``` option to  ```lua54```, ```lua53```, ```lua52```, ```luajit```, or ```lua51``` in the option table when using the library or the command line tools. Candran will try to detect the currently used Lua version and use it as the default target.
 
-For the ```luajit``` and ```lua51``` targets, Lua 5.3 specific syntax (bitwise operators, integer division) will automatically be translated to valid Lua 5.1 syntax, using LuaJIT's ```bit``` library if necessary. Unless LuaJIT's bit library is installed, you won't be able to use bitwise operators with vanilla Lua 5.1 ("PUC Lua").
+Candran will try to translate Lua 5.4 syntax into something usable with the current target if possible. Here is what is currently supported:
 
-The ```lua51``` target does not support gotos and labels.
+| Lua version     | Candran target | Integer division operator // | Bitwise operators                                     | Goto/Labels        | Variable attributes |
+| ---             | ---            | ---                          | ---                                                   | ---                | ---                 |
+| Lua 5.4         | lua54          | :white_check_mark:           | :white_check_mark:                                    | :white_check_mark: | :white_check_mark:  |
+| Lua 5.3         | lua53          | :white_check_mark:           | :white_check_mark:                                    | :white_check_mark: | X                   |
+| Lua 5.2         | lua52          | :white_check_mark:           | :white_check_mark: (32bit)                            | :white_check_mark: | X                   |
+| LuaJIT          | luajit         | :white_check_mark:           | :white_check_mark: (32bit)                            | :white_check_mark: | X                   |
+| Lua 5.1         | lua51          | :white_check_mark:           | :white_check_mark: if LuaJIT bit library is available (32bit) | X                  | X                   |
 
 **Please note** that Candran only translates syntax, and will not try to do anything about changes in the Lua standard library (for example, the new utf8 module). If you need this, you should be able to use [lua-compat-5.3](https://github.com/keplerproject/lua-compat-5.3) along with Candran.
 
 Usage
 -----
 ### Command-line usage
-The library can be used standalone through the ```canc``` and ```can``` utility:
+The library can be used standalone through the ```canc``` (for compiling Candran files) and ```can``` (for running Candran files directly) utilities:
 
 *	````canc````
 
@@ -457,23 +528,41 @@ The library can be used standalone through the ```canc``` and ```can``` utility:
 
 	Preprocess and compile each  _filename_ Candran files, and creates the assiociated ```.lua``` files in the same directories.
 
-	_options_ is of type ````-somearg -anotherarg thing=somestring other=5````, which will generate a Lua table ```{ somearg = true, anotherarg = true, thing = "somestring", other = 5 }```.
+	_options_ is of type ````--no-map-lines -p --include module -d VAR 5````.
 
-	You can choose to use another directory where files should be written using the ```dest=destinationDirectory``` argument.
+	You can choose to use another directory where files should be written using the `--destination` or `-d` option: ```--destination destinationDirectory```.
 
-	You can choose the output filename using ```out=filename```. By default, compiled files have the same name as their input file, but with a ```.lua``` extension.
+	You can choose the output filename using `--output` or `-o` option: `--output filename`. By default, compiled files have the same name as their input file, but with a ```.lua``` extension.
 
-	```canc``` can write to the standard output instead of creating files using the ```-print``` argument.
+	```canc``` can write to the standard output instead of creating files using the ```--print``` or `-p` argument.
 
-	You can choose to run only the preprocessor or compile using the ```-preprocess``` and ```-compile``` flags.
+	You can choose to run only the preprocessor or compile using the ```--preprocess``` and ```--compile``` flags.
 
-	You can choose to only parse the file and check it for syntaxic errors using the ```-parse``` flag. Errors will be printed to stderr in a similar format to ```luac -p```.
+	You can choose to only parse the file and check it for syntaxic errors using the ```--parse``` flag. Errors will be printed to stderr in a similar format to ```luac -p```.
 
-	The ```-ast``` flag is also available for debugging, and will disable preprocessing, compiling and file writing, and instead directly dump the AST generated from the input file(s) to stdout.
+	The ```--ast``` flag is also available for debugging, and will disable preprocessing, compiling and file writing, and instead directly dump the AST generated from the input file(s) to stdout.
 
 	Instead of providing filenames, you can use ```-``` to read from standard input.
 
-	Use the ```-h``` or ```-help``` option to display a short help text.
+	You can change the compiler target using `--target` or `-t`: `--target luajit`.
+
+	You can change the identation and newline string using `--indentation` and `--newline`: `--identation luajit`.
+
+	You can change Candran's built-in variable prefix using `--variable-prefix`: `--variable-prefix __CAN_`.
+
+	You can disable line mapping (error rewriting will not work) using `--no-map-lines`.
+
+	You can disable built-in macros using `--no-builtin-macros`.
+
+	You can define preprocessor constants using `--define` or `-D`: `--define VAR 5`. `VAR` will be available and set to 5 in the preprocessor. If you specify no value, it defaults to true.
+
+	You can statically import modules using `--import` or `-I`: `--import module`. The module will be imported in compiled files using `#import("module",{loadLocal=false})`.
+
+	You can disable error rewriting using `--no-rewrite-errors`.
+
+	You can change the chunkname using `--chunkname`: `--chunkname filename`. This will change the filenames are reported in errors. By default, try to use the current file name, or stdin when using `-`.
+
+	Use the ```-h``` or ```--help``` option to display the help text.
 
 	Example uses:
 
@@ -481,21 +570,21 @@ The library can be used standalone through the ```canc``` and ```can``` utility:
 
 		preprocess and compile _foo.can_ and write the result in _foo.lua_.
 
-	* ````canc indentation="  " foo.can````
+	* ````canc --indentation "  " foo.can````
 
 		preprocess and compile _foo.can_ with 2-space indentation (readable code!) and write the result in _foo.lua_.
 
-	* ````canc foo.can -verbose -print | lua````
+	* ````canc foo.can -d verbose --print | lua````
 
-		preprocess _foo.can_ with _verbose_ set to _true_, compile it and execute it.
+		preprocess _foo.can_ with _verbose_ set to _true_ in the preprocessor, compile it and execute it.
 
-	* ````canc -parse foo.can````
+	* ````canc --parse foo.can````
 
 		checks foo.can for syntaxic errors.
 
 *   ```can```
 
-	Start a simplisitic Candran REPL.
+	Start a simplisitic Candran REPL. Will automatically call `candran.setup()`.
 
 	If you want a better REPL (autocompletion, history, ability to move the cursor), install lua-linenoise: ```luarocks install linenoise``` (automatically installed if Candran was installed using LuaRocks).
 
@@ -503,13 +592,15 @@ The library can be used standalone through the ```canc``` and ```can``` utility:
 
 	Preprocess, compile and run _filename_ using the options provided.
 
-	This will automatically register the Candran package searcher, so required Candran modules will be compiled as they are needed.
+	This will automatically register the Candran package searcher using `candran.setup()`, so required Candran modules will be compiled as they are needed.
 
 	This command will use error rewriting unless explicitely enabled (by setting the `rewriteErrors=false` option).
 
 	Instead of providing a filename, you can use ```-``` to read from standard input.
 
-	Use the ```-h``` or ```-help``` option to display a short help text.
+	Use similar options as `canc`.
+
+	Use the ```-h``` or ```-help``` option to display the help text.
 
 *   ```cancheck```
 
@@ -526,7 +617,7 @@ local f = io.open("foo.can") -- read the file foo.can
 local contents = f:read("*a")
 f:close()
 
-local compiled = candran.make(contents, { debug = true }) -- compile foo.can with debug set to true
+local compiled = candran.make(contents, { DEBUG = true }) -- compile foo.can with DEBUG set to true
 
 load(compiled)() -- execute!
 
@@ -542,14 +633,14 @@ The table returned by _require("candran")_ gives you access to:
 
 ##### Compiler & preprocessor
 * ````candran.VERSION````: Candran's version string (e.g. `"0.10.0"`).
-* ````candran.preprocess(code[, options])````: return the Candran code _code_, preprocessed with the _options_ options table; or nil, err in case of error.
-* ````candran.compile(code[, options])````: return the Candran code compiled to Lua with the _options_ option table; or nil, err in case of error.
+* ````candran.preprocess(code[, options])````: return the Candran code _code_, `macros` table. The code is preprocessed with the _options_ options table; `macros` is indented to be passed to `candran.compile` to apply the defined macros. In case of error, returns nil, error.
+* ````candran.compile(code[, options[, macros]])````: return the Candran code compiled to Lua with the _options_ option table and the macros `macros` (table returned by the preprocessor); or nil, err in case of error.
 * ````candran.make(code[, options])````: return the Candran code, preprocessed and compiled with the _options_ options table; or nil, err in case of error.
 
 ##### Code loading helpers
-* ```candran.loadfile(filepath, env, options)```: Candran equivalent to the Lua 5.3's loadfile funtion. Will rewrite errors by default.
-* ```candran.load(chunk, chunkname, env, options)```: Candran equivalent to the Lua 5.3's load funtion. Will rewrite errors by default.
-* ```candran.dofile(filepath, options)```: Candran equivalent to the Lua 5.3's dofile funtion. Will rewrite errors by default.
+* ```candran.loadfile(filepath, env, options)```: Candran equivalent to the Lua 5.4's loadfile funtion. Will rewrite errors by default.
+* ```candran.load(chunk, chunkname, env, options)```: Candran equivalent to the Lua 5.4's load funtion. Will rewrite errors by default.
+* ```candran.dofile(filepath, options)```: Candran equivalent to the Lua 5.4's dofile funtion. Will rewrite errors by default.
 
 #### Error rewriting
 When using the command-line tools or the code loading helpers, Candran will automatically setup error rewriting: because the code is reformated when
@@ -568,9 +659,13 @@ If you are using the preprocessor ```import()``` function, the source Candran fi
 example.can:12(final.lua:5): attempt to call a nil value (global 'iWantAnError')
 ```
 
-You can perform error rewriting manually using:
+Please note that Candran can only wrap code directly called from Candran; if an error is raised from Lua, there will be no rewriting of Candran lines the stacktrace. These lines are indicated using `(compiled candran)` before the line number.
 
-* ```candran.messageHandler(message)```: the error message handler used by Candran. Given `message` the Lua error string, returns full Candran traceback where soure files and lines are rewritten to their Candran source. You can use it as is in xpcall as a message handler.
+If you want Candran to always wrap errors, you will need to wrap your whole code in a `xpcall`: `xpcall(func, candran.messageHandler)`.
+
+* ```candran.messageHandler(message[, noTraceback])```: the error message handler used by Candran. Given `message` the Lua error string, returns full Candran traceback where soure files and lines are rewritten to their Candran source. You can use it as is in xpcall as a message handler. If `noTraceback` is `true`, Candran will only rewrite `message` and not add a new traceback.
+
+Also note that the Candran message handler will add a new, rewritten, stacktrace to the error message; it can't replace the default Lua one. You will therefore see two stacktraces when raising an error, the last one being the Lua one and can be ignored.
 
 ##### Package searching helpers
 Candran comes with a custom package searcher which will automatically find, preprocesses and compile ```.can``` files.
@@ -584,19 +679,22 @@ require("candran").setup()
 at the top of your main Lua file. If a Candran file is found when you call ```require()```, it will be automatically compiled and loaded. If both a Lua and Candran file match a module name, the Candran file will be loaded.
 
 * ```candran.searcher(modpath)```: Candran package searcher function. Use the existing package.path.
-* ```candran.setup()```: register the Candran package searcher, and return the `candran` table.
+* ```candran.setup()```: register the Candran package searcher (if not already done), and return the `candran` table.
 
 ##### Available compiler & preprocessor options
 You can give arbitrary options to the compiler and preprocessor, but Candran already provide and uses these with their associated default values:
 
 ```lua
-target = "lua53" -- compiler target. "lua53", "luajit" or "lua51" (default is automatically selected based on the Lua version used).
+target = "lua53" -- compiler target. "lua54", "lua53", "lua52", "luajit" or "lua51" (default is automatically selected based on the Lua version used).
 indentation = "" -- character(s) used for indentation in the compiled file.
 newline = "\n" -- character(s) used for newlines in the compiled file.
 variablePrefix = "__CAN_" -- Prefix used when Candran needs to set a local variable to provide some functionality (example: to load LuaJIT's bit lib when using bitwise operators).
 mapLines = true -- if true, compiled files will contain comments at the end of each line indicating the associated line and source file. Needed for error rewriting.
 chunkname = "nil" -- the chunkname used when running code using the helper functions and writing the line origin comments. Candran will try to set it to the original filename if it knows it.
 rewriteErrors = true -- true to enable error rewriting when loading code using the helper functions. Will wrap the whole code in a xpcall().
+builtInMacros = true -- false to disable built-in macros __*__
+preprocessorEnv = {} -- environment to merge with the preprocessor environement
+import = {} -- list of modules to automatically import in compiled files (using #import("module",{loadLocal=false}))
 ```
 
 You can change the defaults used for these variables in the table `candran.default`.

bin/can

@@ -1,44 +1,57 @@
 #!/usr/bin/env lua
 
-local candran = require("candran")
-local cmdline = require("candran.cmdline")
+local candran = require("candran").setup()
+local util = require("candran.util")
+local argparse = require("argparse")
+local unpack = unpack or table.unpack
 
-local args = cmdline(arg)
+-- Parse args --
 
-if args.help or args.h then
-	print("Candran "..candran.VERSION.." interpreter by Reuh")
-	print("Usage: "..arg[0].." [options] filename")
-	print("Specify no options to start the REPL.")
-	print("Use - instead of a filename to read from the standard input.")
-	print("Interpreter options:")
-	print("  -help or -h       print this text")
-	print("Default options:")
-	for opt, val in pairs(candran.default) do
-		if type(val) == "string" then val = val:gsub("\n", "\\n") end
-		print(("  %s=%q"):format(opt, val))
-	end
-	return
-end
+local parser = argparse()
+	:name "can"
+	:description("Candran "..candran.VERSION.." interpreter by Reuh.")
+	:epilog "For more info, see https://github.com/Reuh/candran"
+
+parser:argument("filename", "Candran file to run. Use - to read from standard input. Start the REPL if no filename given.")
+	:args "?"
+
+util.cli.addCandranOptions(parser)
+
+local args = parser:parse()
+
+local options = util.cli.makeCandranOptions(args)
+
+-- Run --
 
 -- stdin
-if arg[#arg] == "-" then
-	local f, err = candran.load(io.read("*a"), "stdin", nil, args)
+if args.filename == "-" then
+	local f, err = candran.load(io.read("*a"), "stdin", nil, options)
 	if not f then
 		io.stderr:write("can: "..err.."\n")
 		os.exit(1)
 	end
-	f()
+	local r, e = xpcall(f, candran.messageHandler)
+	if not r then
+		io.stderr:write(e.."\n")
+		os.exit(1)
+	end
 -- file
-elseif #args >= 1 then
-	local f, err = candran.loadfile(args[1], nil, args)
+elseif args.filename then
+	local f, err = candran.loadfile(args.filename, nil, options)
 	if not f then
 		io.stderr:write("can: "..err.."\n")
 		os.exit(1)
 	else
-		f()
+		local r, e = xpcall(f, candran.messageHandler)
+		if not r then
+			io.stderr:write(e.."\n")
+			os.exit(1)
+		end
 	end
 -- REPL
 else
+	candran.default = util.merge(candran.default, options)
+
 	-- Setup linenoise
 	local s, l = pcall(require, "linenoise")
 	if not s then -- pure Lua compatibility thingy
@@ -105,6 +118,22 @@ else
 	print("Candran " .. candran.VERSION .. ", targeting " .. candran.default.target)
 	candran.setup()
 
+	-- check errors in static import
+	-- note: static imports will be run every line, as preprocessors macros and constants aren't kept between compilations...
+	do
+		local r, e = candran.load("local _", "stdin")
+		if not r then
+			print("In static import: "..e)
+			candran.default.import = {}
+		else
+			r, e = pcall(r)
+			if not r then
+				print("In static import: "..e)
+				candran.default.import = {}
+			end
+		end
+	end
+
 	-- REPL loop
 	local multiline = false -- true if wait for another line
 	local buffer
@@ -144,15 +173,15 @@ else
 		end
 
 		-- exec
-		local t = { pcall(candran.load, buffer, "stdin") }
-		if t[1] == false then
-			if t[2]:match("expected '[end})]+' to close") then
+		local r, e = candran.load(buffer, "stdin")
+		if not r then
+			if e:match("expected '[end})]+' to close") then
 				multiline = true
 			else
-				print(t[2])
+				print(e)
 			end
 		else
-			t = { pcall(t[2]) }
+			local t = { pcall(r) }
 			if t[1] == false then
 				print(t[2])
 			elseif #t > 1 then

bin/canc

@@ -1,48 +1,63 @@
 #!/usr/bin/env lua
 
 local candran = require("candran")
-local cmdline = require("candran.cmdline")
 local parse = require("candran.can-parser.parser").parse
 local pp = require("candran.can-parser.pp")
+local util = require("candran.util")
+local argparse = require("argparse")
 
-local args = cmdline(arg)
+-- Parse args --
 
-if #arg < 1 or args.help or args.h then
-	print("Candran "..candran.VERSION.." compiler by Reuh")
-	print("Usage: "..arg[0].." [options] filenames...")
-	print("Use - instead of filenames to read from the standard input. The output file will be named stdin.lua by default.")
-	print("Compiler options:")
-	print("  dest=\"directory\"  where compiled files should be written")
-	print("  out=\"name.lua\"    output filename. By default, will use the same name as the input file with a .lua extension.")
-	print("  -print            write to the standard output instead of creating files")
-	print("  -preprocess       only run the preprocessor")
-	print("  -compile          only run the compiler")
-	print("  -parse            only parse the file and prints errors to stdout")
-	print("  -ast              (for debugging purposes) only parse the files and dump the AST to stdout")
-	print("  -help or -h       print this text")
-	print("Default options:")
-	for opt, val in pairs(candran.default) do
-		if type(val) == "string" then val = val:gsub("\n", "\\n") end
-		print(("  %s=%q"):format(opt, val))
-	end
-	return
-end
+local parser = argparse()
+	:name "canc"
+	:description("Candran "..candran.VERSION.." compiler by Reuh.")
+	:epilog "For more info, see https://github.com/Reuh/candran"
 
-if arg[#arg] == "-" then
-	table.insert(args, io.stdin)
-end
+parser:argument("filename", "Candran files to compile. Use - to read from standard input; the output file will then be named stdin.lua by default.")
+	:args "+"
 
-for _, file in ipairs(args) do
+parser:group("Output options",
+	parser:option("-d --destination")
+		:description "Where compiled files should be written"
+		:argname "directory",
+
+	parser:option("-o --output")
+		:description "Output filename. (default: same name as the input file with a .lua extension)"
+		:argname "filename",
+
+	parser:flag("-p --print")
+		:description "Write to the standard output instead of creating files",
+
+	parser:flag("--preprocess")
+		:description "Only run the preprocessor",
+
+	parser:flag("--compile")
+		:description "Only run the compiler",
+
+	parser:flag("--parse")
+		:description "Only parse the file and prints syntax errors to stdout",
+
+	parser:flag("--ast")
+		:description"(for debugging purposes) Only parse the files and dump the AST to stdout"
+)
+
+util.cli.addCandranOptions(parser)
+
+local args = parser:parse()
+
+-- Compile --
+
+for _, file in ipairs(args.filename) do
 	-- Read
 	local dest, input
-	if file == io.stdin then
-		dest = args.out or "stdin.lua"
+	if file == "-" then
+		dest = args.output or "stdin.lua"
 
 		input = io.read("*a")
 
 		args.chunkname = "stdin"
 	else
-		dest = args.out or (file:gsub("%.can$", "")..".lua")
+		dest = args.output or (file:gsub("%.can$", "")..".lua")
 
 		local inputFile, err = io.open(file, "r")
 		if not inputFile then
@@ -69,8 +84,10 @@ for _, file in ipairs(args) do
 	end
 
 	-- Compile and output
-	if args.dest then
-		dest = args.dest .. "/" .. dest
+	local options = util.cli.makeCandranOptions(args)
+
+	if args.destination then
+		dest = args.destination .. "/" .. dest
 	end
 
 	if not args.print then
@@ -79,7 +96,7 @@ for _, file in ipairs(args) do
 
 	local out = input
 	if args.preprocess then
-		local r, err = candran.preprocess(out, args)
+		local r, err = candran.preprocess(out, options)
 		if not r then
 			io.stderr:write("canc: "..err.."\n")
 			os.exit(1)
@@ -87,7 +104,7 @@ for _, file in ipairs(args) do
 		out = r
 	end
 	if args.compile then
-		local r, err = candran.compile(out, args)
+		local r, err = candran.compile(out, options)
 		if not r then
 			io.stderr:write("canc: "..err.."\n")
 			os.exit(1)
@@ -95,7 +112,7 @@ for _, file in ipairs(args) do
 		out = r
 	end
 	if args.compile == nil and args.preprocess == nil then
-		local r, err = candran.make(input, args)
+		local r, err = candran.make(input, options)
 		if not r then
 			io.stderr:write("canc: "..err.."\n")
 			os.exit(1)

bin/cancheck

@@ -99,6 +99,13 @@ local function check(can)
 						end
 					end
 
+					-- Errors codes highlighting a identifier (alphanumeric+underscore not starting with a number):
+					-- 1xx: global variables
+					-- 2xx: unused variables
+					-- 3xx: unused values
+					-- 4xx: shadowing delarations
+					local isIdentifier = tonumber(warning.code) >= 100 and tonumber(warning.code) < 500
+
 					-- calculating candran column
 					local can_line = can_lines[warning.can_line]
 					local lua_token = lua_line:sub(warning.column, warning.end_column)
@@ -125,18 +132,26 @@ local function check(can)
 									start, stop = nstart, nstop
 								end
 							end
+						-- for non aliases token that are identifier, check if match is a full identifier
+						-- (avoid things like `let e` matching the e in let)
+						elseif start and isIdentifier then
+							local prev = can_line:sub(start-1, start-1)
+							local next = can_line:sub(stop, stop)
+							if prev:match("[%w_]") or next:match("[%w_]") then
+								can_n = can_n - 1 -- skip this match
+							end
 						end
 						-- found
 						if start then
 							pos = stop
-							warning.can_column, warning.can_end_column = start, stop
+							warning.can_column, warning.can_end_column = start, stop-1
 							can_n = can_n + 1
 						else
 							break
 						end
 					end
 
-					-- AFAIK, prev_column and prev_column_end are not displayed in any warning so we don't need to recalculate them for Candran.
+					-- AFAIK, prev_column and prev_end_column are not displayed in any warning so we don't need to recalculate them for Candran.
 				end
 			end
 		end
@@ -166,6 +181,7 @@ local oldRunner = runner.new
 function runner.new(opts)
 	-- Disable max line length checking (it is compiled code...)
 	opts.max_line_length = false
+	opts.ignore = { "4[23]1/__CAN_.*" }
 	return oldRunner(opts)
 end
 

candran.can

@@ -1,7 +1,14 @@
-#import("candran.util")
-#import("candran.cmdline")
+local candran = {
+	VERSION = "1.0.0"
+}
+package.loaded["candran"] = candran
 
+#import("candran.util")
+#import("candran.serpent")
+
+#import("compiler.lua54")
 #import("compiler.lua53")
+#import("compiler.lua52")
 #import("compiler.luajit")
 #import("compiler.lua51")
 
@@ -10,19 +17,20 @@
 #import("candran.can-parser.pp")
 #import("candran.can-parser.parser")
 
-local candran = {
-	VERSION = "0.12.0"
-}
+local unpack = unpack or table.unpack
 
 --- Default options.
 candran.default = {
-	target = "lua53",
+	target = "lua54",
 	indentation = "",
 	newline = "\n",
 	variablePrefix = "__CAN_",
 	mapLines = true,
 	chunkname = "nil",
-	rewriteErrors = true
+	rewriteErrors = true,
+	builtInMacros = true,
+	preprocessorEnv = {},
+	import = {}
 }
 
 -- Autodetect version
@@ -32,16 +40,30 @@ if _VERSION == "Lua 5.1" then
 	else
 		candran.default.target = "lua51"
 	end
+elseif _VERSION == "Lua 5.2" then
+	candran.default.target = "lua52"
+elseif _VERSION == "Lua 5.3" then
+	candran.default.target = "lua53"
 end
 
 --- Run the preprocessor
 -- @tparam input string input code
 -- @tparam options table arguments for the preprocessor. They will be inserted into the preprocessor environement.
 -- @treturn[1] output string output code
+-- @treturn[1] macros registered macros
 -- @treturn[2] nil nil if error
 -- @treturn[2] error string error message
-function candran.preprocess(input, options={})
+function candran.preprocess(input, options={}, _env)
 	options = util.merge(candran.default, options)
+	local macros = {
+		functions = {},
+		variables = {}
+	}
+
+	-- add auto imports
+	for _, mod in ipairs(options.import) do
+		input =.. "#import(%q, {loadLocal=false})\n":format(mod)
+	end
 
 	-- generate preprocessor code
 	local preprocessor = ""
@@ -76,7 +98,8 @@ function candran.preprocess(input, options={})
 	preprocessor ..= "return output"
 
 	-- make preprocessor environement
-	local env = util.merge(_G, options)
+	local exportenv = {}
+	local env = util.merge(_G, options.preprocessorEnv)
 	--- Candran library table
 	env.candran = candran
 	--- Current preprocessor output
@@ -95,7 +118,10 @@ function candran.preprocess(input, options={})
 		if not f then error("can't open the module file to import") end
 
 		margs = util.merge(options, { chunkname = filepath, loadLocal = true, loadPackage = true }, margs)
-		local modcontent = assert(candran.preprocess(f:read("*a"), margs))
+		margs.import = {} -- no need for recursive import
+		local modcontent, modmacros, modenv = assert(candran.preprocess(f:read("*a"), margs))
+		macros = util.recmerge(macros, modmacros)
+		for k, v in pairs(modenv) do env[k] = v end
 		f:close()
 
 		-- get module name (ex: module name of path.to.module is module)
@@ -131,6 +157,48 @@ function candran.preprocess(input, options={})
 			env.write(env[name])
 		end
 	end
+	env.define = function(identifier, replacement)
+		-- parse identifier
+		local iast, ierr = parser.parsemacroidentifier(identifier, options.chunkname)
+		if not iast then
+			return error("in macro identifier: %s":format(tostring(ierr)))
+		end
+		-- parse replacement value
+		if type(replacement) == "string" then
+			local rast, rerr = parser.parse(replacement, options.chunkname)
+			if not rast then
+				return error("in macro replacement: %s":format(tostring(rerr)))
+			end
+			-- when giving a single value as a replacement, bypass the implicit push
+			if #rast == 1 and rast[1].tag == "Push" and rast[1].implicit then
+				rast = rast[1][1]
+			end
+			replacement = rast
+		elseif type(replacement) ~= "function" then
+			error("bad argument #2 to 'define' (string or function expected)")
+		end
+		-- add macros
+		if iast.tag == "MacroFunction" then
+			macros.functions[iast[1][1]] = { args = iast[2], replacement = replacement }
+		elseif iast.tag == "Id" then
+			macros.variables[iast[1]] = replacement
+		else
+			error("invalid macro type %s":format(tostring(iast.tag)))
+		end
+	end
+	env.set = function(identifier, value)
+		exportenv[identifier] = value
+		env[identifier] = value
+	end
+
+	-- default macros
+	if options.builtInMacros then
+		env.define("__STR__(x)", function(x) return ("%q"):format(x) end)
+		local s = require("candran.serpent")
+		env.define("__CONSTEXPR__(expr)", function(expr)
+			return s.block(assert(candran.load(expr))(), {fatal = true})
+		end)
+	end
 
 	-- compile & load preprocessor
 	local preprocess, err = candran.compile(preprocessor, options)
@@ -149,16 +217,17 @@ function candran.preprocess(input, options={})
 		return nil, "in preprocessor: "..output
 	end
 
-	return output
+	return output, macros, exportenv
 end
 
 --- Run the compiler
 -- @tparam input string input code
 -- @tparam options table options for the compiler
+-- @tparam macros table defined macros, as returned by the preprocessor
 -- @treturn[1] output string output code
 -- @treturn[2] nil nil if error
 -- @treturn[2] error string error message
-function candran.compile(input, options={})
+function candran.compile(input, options={}, macros)
 	options = util.merge(candran.default, options)
 
 	local ast, errmsg = parser.parse(input, options.chunkname)
@@ -167,7 +236,7 @@ function candran.compile(input, options={})
 		return nil, errmsg
 	end
 
-	return require("compiler."..options.target)(input, ast, options)
+	return require("compiler."..options.target)(input, ast, options, macros)
 end
 
 --- Preprocess & compile code
@@ -179,7 +248,7 @@ end
 function candran.make(code, options)
 	local r, err = candran.preprocess(code, options)
 	if r then
-		r, err = candran.compile(r, options)
+		r, err = candran.compile(r, options, err)
 		if r then
 			return r
 		end
@@ -194,7 +263,7 @@ local codeCache = {}
 function candran.loadfile(filepath, env, options)
 	local f, err = io.open(filepath)
 	if not f then
-		return nil, "cannot open %s":format(err)
+		return nil, "cannot open %s":format(tostring(err))
 	end
 	local content = f:read("*a")
 	f:close()
@@ -213,7 +282,8 @@ function candran.load(chunk, chunkname, env, options={})
 	end
 
 	codeCache[options.chunkname] = code
-	local f, err = util.load(code, options.chunkname, env)
+	local f
+	f, err = util.load(code, "=%s(%s)":format(options.chunkname, "compiled candran"), env)
 
 	-- Um. Candran isn't supposed to generate invalid Lua code, so this is a major issue.
 	-- This is not going to raise an error because this is supposed to behave similarly to Lua's load function.
@@ -226,10 +296,9 @@ function candran.load(chunk, chunkname, env, options={})
 		return f
 	else
 		return function(...)
-			local params = {...}
 			if not errorRewritingActive then
 				errorRewritingActive = true
-				local t = { xpcall(() return f(unpack(params)) end, candran.messageHandler) }
+				local t = { xpcall(f, candran.messageHandler, ...) }
 				errorRewritingActive = false
 				if t[1] == false then
 					error(t[2], 0)
@@ -256,20 +325,23 @@ end
 
 --- Candran error message handler.
 -- Use it in xpcall to rewrite stacktraces to display Candran source file lines instead of compiled Lua lines.
-function candran.messageHandler(message)
-	return debug.traceback(message, 2):gsub("(\n?%s*)([^\n]-)%:(%d+)%:", function(indentation, source, line)
+function candran.messageHandler(message, noTraceback)
+	message = tostring(message)
+	if not noTraceback and not message:match("\nstack traceback:\n") then
+		message = debug.traceback(message, 2)
+	end
+	return message:gsub("(\n?%s*)([^\n]-)%:(%d+)%:", function(indentation, source, line)
 		line = tonumber(line)
 
 		local originalFile
-		local strName = source:match("%[string \"(.-)\"%]")
+		local strName = source:match("^(.-)%(compiled candran%)$")
 		if strName then
 			if codeCache[strName] then
 				originalFile = codeCache[strName]
 				source = strName
 			end
 		else
-			local fi = io.open(source, "r")
-			if fi then
+			if fi = io.open(source, "r") then
 				originalFile = fi:read("*a")
 				fi:close()
 			end
@@ -299,18 +371,37 @@ end
 function candran.searcher(modpath)
 	local filepath = util.search(modpath, {"can"})
 	if not filepath then
+		if _VERSION == "Lua 5.4" then
+			return "no candran file in package.path"
+		else
 			return "\n\tno candran file in package.path"
 		end
-	return candran.loadfile(filepath)
+	end
+	return (modpath) -- 2nd argument is not passed in Lua 5.1, so a closure is required
+		local r, s = candran.loadfile(filepath)
+		if r then
+			return r(modpath, filepath)
+		else
+			error("error loading candran module '%s' from file '%s':\n\t%s":format(modpath, filepath, tostring(s)), 0)
+		end
+	end, filepath
 end
 
 --- Register the Candran package searcher.
 function candran.setup()
-	if _VERSION == "Lua 5.1" then
-		table.insert(package.loaders, 2, candran.searcher)
+	local searchers = if _VERSION == "Lua 5.1" then
+		package.loaders
 	else
-		table.insert(package.searchers, 2, candran.searcher)
+		package.searchers
 	end
+	-- check if already setup
+	for _, s in ipairs(searchers) do
+		if s == candran.searcher then
+			return candran
+		end
+	end
+	-- setup
+	table.insert(searchers, 1, candran.searcher)
 	return candran
 end
 

candran/can-parser/parser.lua

@@ -14,7 +14,7 @@ stat:
   | `If{ (lexpr block)+ block? }              -- if e1 then b1 [elseif e2 then b2] ... [else bn] end
   | `Fornum{ ident expr expr expr? block }    -- for ident = e, e[, e] do b end
   | `Forin{ {ident+} {expr+} block }          -- for i1, i2... in e1, e2... do b end
-  | `Local{ {ident+} {expr+}? }               -- local i1, i2... = e1, e2...
+  | `Local{ {attributeident+} {expr+}? }      -- local i1, i2... = e1, e2...
   | `Let{ {ident+} {expr+}? }                 -- let i1, i2... = e1, e2...
   | `Localrec{ {ident} {expr} }               -- only used for 'local function'
   | `Goto{ <string> }                         -- goto str
@@ -59,7 +59,7 @@ apply:
     `Call{ expr expr* }
   | `SafeCall{ expr expr* }
 
-lhs: `Id{ <string> } | `Index{ expr expr } | ˇDestructuringId{ Id | Pair+ }
+lhs: `Id{ <string> } | AttributeId{ <string> <string>? } | `Index{ expr expr } | ˇDestructuringId{ Id | Pair+ }
 
 opid:  -- includes additional operators from Lua 5.3 and all relational operators
     'add'  | 'sub' | 'mul'  | 'div'
@@ -113,7 +113,9 @@ local labels = {
   { "ErrDoFor", "expected 'do' after the range of the for loop" },
 
   { "ErrDefLocal", "expected a function definition or assignment after local" },
-  { "ErrDefLet", "expected a function definition or assignment after let" },
+  { "ErrDefLet", "expected an assignment after let" },
+  { "ErrDefClose", "expected an assignment after close" },
+  { "ErrDefConst", "expected an assignment after const" },
   { "ErrNameLFunc", "expected a function name after 'function'" },
   { "ErrEListLAssign", "expected one or more expressions after '='" },
   { "ErrEListAssign", "expected one or more expressions after '='" },
@@ -181,6 +183,9 @@ local labels = {
   { "ErrCBraceUEsc", "expected '}' after the code point" },
   { "ErrEscSeq", "invalid escape sequence" },
   { "ErrCloseLStr", "unclosed long string" },
+
+  { "ErrUnknownAttribute", "unknown variable attribute" },
+  { "ErrCBracketAttribute", "expected '>' to close the variable attribute" },
 }
 
 local function throw(label)
@@ -301,6 +306,11 @@ local function fixShortFunc (t)
     return t
 end
 
+local function markImplicit (t)
+    t.implicit = true
+    return t
+end
+
 local function statToExpr (t) -- tag a StatExpr
     t.tag = t.tag .. "Expr"
     return t
@@ -456,6 +466,24 @@ local function maybe (patt) -- fail pattern instead of propagating errors
   return #patt/0 * patt
 end
 
+local function setAttribute(attribute)
+  return function(assign)
+    assign[1].tag = "AttributeNameList"
+    for _, id in ipairs(assign[1]) do
+      if id.tag == "Id" then
+        id.tag = "AttributeId"
+        id[2] = attribute
+      elseif id.tag == "DestructuringId" then
+        for _, did in ipairs(id) do
+          did.tag = "AttributeId"
+          did[2] = attribute
+        end
+      end
+    end
+    return assign
+  end
+end
+
 local stacks = {
   lexpr = {}
 }
@@ -488,7 +516,7 @@ local G = { V"Lua",
   Block       = tagC("Block", (V"Stat" + -V"BlockEnd" * throw("InvalidStat"))^0 * ((V"RetStat" + V"ImplicitPushStat") * sym(";")^-1)^-1);
   Stat        = V"IfStat" + V"DoStat" + V"WhileStat" + V"RepeatStat" + V"ForStat"
               + V"LocalStat" + V"FuncStat" + V"BreakStat" + V"LabelStat" + V"GoToStat"
-              + V"LetStat"
+              + V"LetStat" + V"ConstStat" + V"CloseStat"
               + V"FuncCall" + V"Assignment"
               + V"ContinueStat" + V"PushStat"
               + sym(";");
@@ -516,13 +544,18 @@ local G = { V"Lua",
 
   LocalStat    = kw("local") * expect(V"LocalFunc" + V"LocalAssign", "DefLocal");
   LocalFunc    = tagC("Localrec", kw("function") * expect(V"Id", "NameLFunc") * V"FuncBody") / fixFuncStat;
-  LocalAssign  = tagC("Local", V"NameList" * (sym("=") * expect(V"ExprList", "EListLAssign") + Ct(Cc())))
+  LocalAssign  = tagC("Local", V"AttributeNameList" * (sym("=") * expect(V"ExprList", "EListLAssign") + Ct(Cc())))
                + tagC("Local", V"DestructuringNameList" * sym("=") * expect(V"ExprList", "EListLAssign"));
 
   LetStat      = kw("let") * expect(V"LetAssign", "DefLet");
   LetAssign    = tagC("Let", V"NameList" * (sym("=") * expect(V"ExprList", "EListLAssign") + Ct(Cc())))
                + tagC("Let", V"DestructuringNameList" * sym("=") * expect(V"ExprList", "EListLAssign"));
 
+  ConstStat       = kw("const") * expect(V"AttributeAssign" / setAttribute("const"), "DefConst");
+  CloseStat       = kw("close") * expect(V"AttributeAssign" / setAttribute("close"), "DefClose");
+  AttributeAssign = tagC("Local", V"NameList" * (sym("=") * expect(V"ExprList", "EListLAssign") + Ct(Cc())))
+                  + tagC("Local", V"DestructuringNameList" * sym("=") * expect(V"ExprList", "EListLAssign"));
+
   Assignment   = tagC("Set", (V"VarList" + V"DestructuringNameList") * V"BinOp"^-1 * (P"=" / "=") * ((V"BinOp" - P"-") + #(P"-" * V"Space") * V"BinOp")^-1 * V"Skip" * expect(V"ExprList", "EListAssign"));
 
   FuncStat    = tagC("Set", kw("function") * expect(V"FuncName", "FuncName") * V"FuncBody") / fixFuncStat;
@@ -549,10 +582,11 @@ local G = { V"Lua",
   RetStat         = tagC("Return", kw("return") * commaSep(V"Expr", "RetList")^-1);
 
   PushStat         = tagC("Push", kw("push") * commaSep(V"Expr", "RetList")^-1);
-  ImplicitPushStat = tagC("Push", commaSep(V"Expr", "RetList"));
+  ImplicitPushStat = tagC("Push", commaSep(V"Expr", "RetList")) / markImplicit;
 
   NameList              = tagC("NameList", commaSep(V"Id"));
   DestructuringNameList = tagC("NameList", commaSep(V"DestructuringId")),
+  AttributeNameList     = tagC("AttributeNameList", commaSep(V"AttributeId"));
   VarList   = tagC("VarList", commaSep(V"VarExpr"));
   ExprList  = tagC("ExpList", commaSep(V"Expr", "ExprList"));
 
@@ -626,8 +660,12 @@ local G = { V"Lua",
 
   SelfId = tagC("Id", sym"@" / "self");
   Id     = tagC("Id", V"Name") + V"SelfId";
+  AttributeSelfId = tagC("AttributeId", sym"@" / "self" * V"Attribute"^-1);
+  AttributeId     = tagC("AttributeId", V"Name" * V"Attribute"^-1) + V"AttributeSelfId";
   StrId  = tagC("String", V"Name");
 
+  Attribute = sym("<") * expect(kw"const" / "const" + kw"close" / "close", "UnknownAttribute") * expect(sym(">"), "CBracketAttribute");
+
   -- lexer
   Skip     = (V"Space" + V"Comment")^0;
   Space    = space^1;
@@ -724,6 +762,20 @@ local G = { V"Lua",
   BinOp     = V"OrOp" + V"AndOp" + V"BOrOp" + V"BXorOp" + V"BAndOp" + V"ShiftOp" + V"ConcatOp" + V"AddOp" + V"MulOp" + V"PowOp";
 }
 
+-- used to parse macro indentifier in define() preprocessor function
+local macroidentifier = {
+  expect(V"MacroIdentifier", "InvalidStat") * expect(P(-1), "Extra"),
+
+  MacroIdentifier   = tagC("MacroFunction", V"Id" * sym("(") * V"MacroFunctionArgs" * expect(sym(")"), "CParenPList"))
+                    + V"Id";
+
+  MacroFunctionArgs = V"NameList" * (sym(",") * expect(tagC("Dots", sym("...")), "ParList"))^-1 / addDots
+                    + Ct(tagC("Dots", sym("...")))
+                    + Ct(Cc());
+
+}
+for k,v in pairs(G) do if macroidentifier[k] == nil then macroidentifier[k] = v end end -- copy other rules from main syntax
+
 local parser = {}
 
 local validator = require("candran.can-parser.validator")
@@ -741,4 +793,15 @@ function parser.parse (subject, filename)
   return validate(ast, errorinfo)
 end
 
+function parser.parsemacroidentifier (subject, filename)
+  local errorinfo = { subject = subject, filename = filename }
+  lpeg.setmaxstack(1000)
+  local ast, label, errpos = lpeg.match(macroidentifier, subject, nil, errorinfo)
+  if not ast then
+    local errmsg = labels[label][2]
+    return ast, syntaxerror(errorinfo, errpos, errmsg)
+  end
+  return ast
+end
+
 return parser

candran/cmdline.lua

@@ -1,126 +0,0 @@
--- started: 2008-04-12 by Shmuel Zeigerman
--- license: public domain
-
-local ipairs,pairs,setfenv,tonumber,loadstring,type =
-  ipairs,pairs,setfenv,tonumber,loadstring,type
-local tinsert, tconcat = table.insert, table.concat
-
-local function commonerror (msg)
-  return nil, ("[cmdline]: " .. msg)
-end
-
-local function argerror (msg, numarg)
-  msg = msg and (": " .. msg) or ""
-  return nil, ("[cmdline]: bad argument #" .. numarg .. msg)
-end
-
-local function iderror (numarg)
-  return argerror("ID not valid", numarg)
-end
-
-local function idcheck (id)
-  return id:match("^[%a_][%w_]*$") and true
-end
-
---[[------------------------------------------------------------------------
-Syntax:
-  t_out = getparam(t_in [,options] [,params])
-
-Parameters:
-  t_in:   table - list of string arguments to be processed in order
-          (usually it is the `arg' table created by the Lua interpreter).
-
-     * if an argument begins with $, the $ is skipped and the rest is inserted
-       into the array part of the output table.
-
-     * if an argument begins with -, the rest is a sequence of variables
-       (separated by commas or semicolons) that are all set to true;
-            example: -var1,var2  --> var1,var2 = true,true
-
-     * if an argument begins with !, the rest is a Lua chunk;
-            example: !a=(40+3)*5;b=20;name="John";window={w=600,h=480}
-
-     * if an argument contains =, then it is an assignment in the form
-       var1,...=value (no space is allowed around the =)
-         * if value begins with $, the $ is skipped, the rest is a string
-                 example: var1,var2=$         --> var1,var2 = "",""
-                 example: var1,var2=$125      --> var1,var2 = "125","125"
-                 example: var1,var2=$$125     --> var1,var2 = "$125","$125"
-         * if value is convertible to number, it is a number
-                 example: var1,var2=125       --> var1,var2 = 125,125
-         * if value is true of false, it is a boolean
-                 example: var1=false          --> var1 = false
-         * otherwise it is a string
-                 example: name=John           --> name = "John"
-
-     * if an argument neither begins with one of the special characters (-,!,$),
-       nor contains =, it is inserted as is into the array part of the output
-       table.
-
-  options (optional): a list of names of all command-line options and parameters
-     permitted in the application; used to check that each found option
-     is valid; no checks are done if not supplied.
-
-  params (optional): a list of names of all command-line parameters required
-     by the application; used to check that each required parameter is present;
-     no checks are done if not supplied.
-
-Returns:
-  On success: the output table, e.g. { [1]="./myfile.txt", name="John", age=40 }
-  On error: nil followed by error message string.
-
---]]------------------------------------------------------------------------
-return function(t_in, options, params)
-  local t_out = {}
-  for i,v in ipairs(t_in) do
-    local prefix, command = v:sub(1,1), v:sub(2)
-    if prefix == "$" then
-      tinsert(t_out, command)
-    elseif prefix == "-" then
-      for id in command:gmatch"[^,;]+" do
-        if not idcheck(id) then return iderror(i) end
-        t_out[id] = true
-      end
-    elseif prefix == "!" then
-      local f, err = loadstring(command)
-      if not f then return argerror(err, i) end
-      setfenv(f, t_out)()
-    elseif v:find("=") then
-      local ids, val = v:match("^([^=]+)%=(.*)") -- no space around =
-      if not ids then return argerror("invalid assignment syntax", i) end
-      if val == "false" then
-          val = false
-      elseif val == "true" then
-          val = true
-      else
-          val = val:sub(1,1)=="$" and val:sub(2) or tonumber(val) or val
-      end
-      for id in ids:gmatch"[^,;]+" do
-        if not idcheck(id) then return iderror(i) end
-        t_out[id] = val
-      end
-    else
-      tinsert(t_out, v)
-    end
-  end
-  if options then
-    local lookup, unknown = {}, {}
-    for _,v in ipairs(options) do lookup[v] = true end
-    for k,_ in pairs(t_out) do
-      if lookup[k]==nil and type(k)=="string" then tinsert(unknown, k) end
-    end
-    if #unknown > 0 then
-      return commonerror("unknown options: " .. tconcat(unknown, ", "))
-    end
-  end
-  if params then
-    local missing = {}
-    for _,v in ipairs(params) do
-      if t_out[v]==nil then tinsert(missing, v) end
-    end
-    if #missing > 0 then
-      return commonerror("missing parameters: " .. tconcat(missing, ", "))
-    end
-  end
-  return t_out
-end

candran/serpent.lua

@@ -0,0 +1,163 @@
+--[[
+Serpent source is released under the MIT License
+
+Copyright (c) 2012-2018 Paul Kulchenko (paul@kulchenko.com)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+]]
+local n, v = "serpent", "0.302" -- (C) 2012-18 Paul Kulchenko; MIT License
+local c, d = "Paul Kulchenko", "Lua serializer and pretty printer"
+local snum = {[tostring(1/0)]='1/0 --[[math.huge]]',[tostring(-1/0)]='-1/0 --[[-math.huge]]',[tostring(0/0)]='0/0'}
+local badtype = {thread = true, userdata = true, cdata = true}
+local getmetatable = debug and debug.getmetatable or getmetatable
+local pairs = function(t) return next, t end -- avoid using __pairs in Lua 5.2+
+local keyword, globals, G = {}, {}, (_G or _ENV)
+for _,k in ipairs({'and', 'break', 'do', 'else', 'elseif', 'end', 'false',
+  'for', 'function', 'goto', 'if', 'in', 'local', 'nil', 'not', 'or', 'repeat',
+  'return', 'then', 'true', 'until', 'while'}) do keyword[k] = true end
+for k,v in pairs(G) do globals[v] = k end -- build func to name mapping
+for _,g in ipairs({'coroutine', 'debug', 'io', 'math', 'string', 'table', 'os'}) do
+  for k,v in pairs(type(G[g]) == 'table' and G[g] or {}) do globals[v] = g..'.'..k end end
+
+local function s(t, opts)
+  local name, indent, fatal, maxnum = opts.name, opts.indent, opts.fatal, opts.maxnum
+  local sparse, custom, huge = opts.sparse, opts.custom, not opts.nohuge
+  local space, maxl = (opts.compact and '' or ' '), (opts.maxlevel or math.huge)
+  local maxlen, metatostring = tonumber(opts.maxlength), opts.metatostring
+  local iname, comm = '_'..(name or ''), opts.comment and (tonumber(opts.comment) or math.huge)
+  local numformat = opts.numformat or "%.17g"
+  local seen, sref, syms, symn = {}, {'local '..iname..'={}'}, {}, 0
+  local function gensym(val) return '_'..(tostring(tostring(val)):gsub("[^%w]",""):gsub("(%d%w+)",
+    -- tostring(val) is needed because __tostring may return a non-string value
+    function(s) if not syms[s] then symn = symn+1; syms[s] = symn end return tostring(syms[s]) end)) end
+  local function safestr(s) return type(s) == "number" and tostring(huge and snum[tostring(s)] or numformat:format(s))
+    or type(s) ~= "string" and tostring(s) -- escape NEWLINE/010 and EOF/026
+    or ("%q"):format(s):gsub("\010","n"):gsub("\026","\\026") end
+  local function comment(s,l) return comm and (l or 0) < comm and ' --[['..select(2, pcall(tostring, s))..']]' or '' end
+  local function globerr(s,l) return globals[s] and globals[s]..comment(s,l) or not fatal
+    and safestr(select(2, pcall(tostring, s))) or error("Can't serialize "..tostring(s)) end
+  local function safename(path, name) -- generates foo.bar, foo[3], or foo['b a r']
+    local n = name == nil and '' or name
+    local plain = type(n) == "string" and n:match("^[%l%u_][%w_]*$") and not keyword[n]
+    local safe = plain and n or '['..safestr(n)..']'
+    return (path or '')..(plain and path and '.' or '')..safe, safe end
+  local alphanumsort = type(opts.sortkeys) == 'function' and opts.sortkeys or function(k, o, n) -- k=keys, o=originaltable, n=padding
+    local maxn, to = tonumber(n) or 12, {number = 'a', string = 'b'}
+    local function padnum(d) return ("%0"..tostring(maxn).."d"):format(tonumber(d)) end
+    table.sort(k, function(a,b)
+      -- sort numeric keys first: k[key] is not nil for numerical keys
+      return (k[a] ~= nil and 0 or to[type(a)] or 'z')..(tostring(a):gsub("%d+",padnum))
+           < (k[b] ~= nil and 0 or to[type(b)] or 'z')..(tostring(b):gsub("%d+",padnum)) end) end
+  local function val2str(t, name, indent, insref, path, plainindex, level)
+    local ttype, level, mt = type(t), (level or 0), getmetatable(t)
+    local spath, sname = safename(path, name)
+    local tag = plainindex and
+      ((type(name) == "number") and '' or name..space..'='..space) or
+      (name ~= nil and sname..space..'='..space or '')
+    if seen[t] then -- already seen this element
+      sref[#sref+1] = spath..space..'='..space..seen[t]
+      return tag..'nil'..comment('ref', level) end
+    -- protect from those cases where __tostring may fail
+    if type(mt) == 'table' and metatostring ~= false then
+      local to, tr = pcall(function() return mt.__tostring(t) end)
+      local so, sr = pcall(function() return mt.__serialize(t) end)
+      if (to or so) then -- knows how to serialize itself
+        seen[t] = insref or spath
+        t = so and sr or tr
+        ttype = type(t)
+      end -- new value falls through to be serialized
+    end
+    if ttype == "table" then
+      if level >= maxl then return tag..'{}'..comment('maxlvl', level) end
+      seen[t] = insref or spath
+      if next(t) == nil then return tag..'{}'..comment(t, level) end -- table empty
+      if maxlen and maxlen < 0 then return tag..'{}'..comment('maxlen', level) end
+      local maxn, o, out = math.min(#t, maxnum or #t), {}, {}
+      for key = 1, maxn do o[key] = key end
+      if not maxnum or #o < maxnum then
+        local n = #o -- n = n + 1; o[n] is much faster than o[#o+1] on large tables
+        for key in pairs(t) do if o[key] ~= key then n = n + 1; o[n] = key end end end
+      if maxnum and #o > maxnum then o[maxnum+1] = nil end
+      if opts.sortkeys and #o > maxn then alphanumsort(o, t, opts.sortkeys) end
+      local sparse = sparse and #o > maxn -- disable sparsness if only numeric keys (shorter output)
+      for n, key in ipairs(o) do
+        local value, ktype, plainindex = t[key], type(key), n <= maxn and not sparse
+        if opts.valignore and opts.valignore[value] -- skip ignored values; do nothing
+        or opts.keyallow and not opts.keyallow[key]
+        or opts.keyignore and opts.keyignore[key]
+        or opts.valtypeignore and opts.valtypeignore[type(value)] -- skipping ignored value types
+        or sparse and value == nil then -- skipping nils; do nothing
+        elseif ktype == 'table' or ktype == 'function' or badtype[ktype] then
+          if not seen[key] and not globals[key] then
+            sref[#sref+1] = 'placeholder'
+            local sname = safename(iname, gensym(key)) -- iname is table for local variables
+            sref[#sref] = val2str(key,sname,indent,sname,iname,true) end
+          sref[#sref+1] = 'placeholder'
+          local path = seen[t]..'['..tostring(seen[key] or globals[key] or gensym(key))..']'
+          sref[#sref] = path..space..'='..space..tostring(seen[value] or val2str(value,nil,indent,path))
+        else
+          out[#out+1] = val2str(value,key,indent,nil,seen[t],plainindex,level+1)
+          if maxlen then
+            maxlen = maxlen - #out[#out]
+            if maxlen < 0 then break end
+          end
+        end
+      end
+      local prefix = string.rep(indent or '', level)
+      local head = indent and '{\n'..prefix..indent or '{'
+      local body = table.concat(out, ','..(indent and '\n'..prefix..indent or space))
+      local tail = indent and "\n"..prefix..'}' or '}'
+      return (custom and custom(tag,head,body,tail,level) or tag..head..body..tail)..comment(t, level)
+    elseif badtype[ttype] then
+      seen[t] = insref or spath
+      return tag..globerr(t, level)
+    elseif ttype == 'function' then
+      seen[t] = insref or spath
+      if opts.nocode then return tag.."function() --[[..skipped..]] end"..comment(t, level) end
+      local ok, res = pcall(string.dump, t)
+      local func = ok and "((loadstring or load)("..safestr(res)..",'@serialized'))"..comment(t, level)
+      return tag..(func or globerr(t, level))
+    else return tag..safestr(t) end -- handle all other types
+  end
+  local sepr = indent and "\n" or ";"..space
+  local body = val2str(t, name, indent) -- this call also populates sref
+  local tail = #sref>1 and table.concat(sref, sepr)..sepr or ''
+  local warn = opts.comment and #sref>1 and space.."--[[incomplete output with shared/self-references skipped]]" or ''
+  return not name and body..warn or "do local "..body..sepr..tail.."return "..name..sepr.."end"
+end
+
+local function deserialize(data, opts)
+  local env = (opts and opts.safe == false) and G
+    or setmetatable({}, {
+        __index = function(t,k) return t end,
+        __call = function(t,...) error("cannot call functions") end
+      })
+  local f, res = (loadstring or load)('return '..data, nil, nil, env)
+  if not f then f, res = (loadstring or load)(data, nil, nil, env) end
+  if not f then return f, res end
+  if setfenv then setfenv(f, env) end
+  return pcall(f)
+end
+
+local function merge(a, b) if b then for k,v in pairs(b) do a[k] = v end end; return a; end
+return { _NAME = n, _COPYRIGHT = c, _DESCRIPTION = d, _VERSION = v, serialize = s,
+  load = deserialize,
+  dump = function(a, opts) return s(a, merge({name = '_', compact = true, sparse = true}, opts)) end,
+  line = function(a, opts) return s(a, merge({sortkeys = true, comment = true}, opts)) end,
+  block = function(a, opts) return s(a, merge({indent = '  ', sortkeys = true, comment = true}, opts)) end }

candran/util.can

@@ -1,3 +1,4 @@
+local candran = require("candran")
 local util = {}
 
 function util.search(modpath, exts={})
@@ -27,6 +28,20 @@ function util.load(str, name, env)
 	end
 end
 
+function util.recmerge(...)
+	local r = {}
+	for _, t in ipairs({...}) do
+		for k, v in pairs(t) do
+			if type(v) == "table" then
+				r[k] = util.merge(v, r[k])
+			else
+				r[k] = v
+			end
+		end
+	end
+	return r
+end
+
 function util.merge(...)
 	local r = {}
 	for _, t in ipairs({...}) do
@@ -37,4 +52,74 @@ function util.merge(...)
 	return r
 end
 
+util.cli = {
+	-- add option to set Candran options to an argparse parser
+	addCandranOptions = function(parser)
+		parser:group("Compiler options",
+			parser:option("-t --target")
+				:description "Target Lua version: lua54, lua53, lua52, luajit or lua51"
+				:default(candran.default.target),
+
+			parser:option("--indentation")
+				:description "Character(s) used for indentation in the compiled file"
+				:default(candran.default.indentation),
+
+			parser:option("--newline")
+				:description "Character(s) used for newlines in the compiled file"
+				:default(candran.default.newline),
+
+			parser:option("--variable-prefix")
+				:description "Prefix used when Candran needs to set a local variable to provide some functionality"
+				:default(candran.default.variablePrefix),
+
+			parser:flag("--no-map-lines")
+				:description "Do not add comments at the end of each line indicating the associated source line and file (error rewriting will not work)"
+		)
+
+		parser:group("Preprocessor options",
+			parser:flag("--no-builtin-macros")
+				:description "Disable built-in macros",
+
+			parser:option("-D --define")
+				:description "Define a preprocessor constant"
+				:args("1-2")
+				:argname{"name", "value"}
+				:count("*"),
+
+			parser:option("-I --import")
+				:description "Statically import a module into the compiled file"
+				:argname("module")
+				:count("*")
+		)
+
+		parser:option("--chunkname")
+			:description "Chunkname used when running the code"
+
+		parser:flag("--no-rewrite-errors")
+			:description "Disable error rewriting when running the code"
+	end,
+
+	-- convert parsed arguments to a Candran options table
+	makeCandranOptions = function(args)
+		local preprocessorEnv = {}
+		for _, o in ipairs(args.define) do
+			preprocessorEnv[o[1]] = tonumber(o[2]) or o[2] or true
+		end
+
+		local options = {
+			target = args.target,
+			indentation = args.indentation,
+			newline = args.newline,
+			variablePrefix = args.variable_prefix,
+			mapLines = not args.no_map_lines,
+			chunkname = args.chunkname,
+			rewriteErrors = not args.no_rewrite_errors,
+			builtInMacros = not args.no_builtin_macros,
+			preprocessorEnv = preprocessorEnv,
+			import = args.import
+		}
+		return options
+	end
+}
+
 return util

compiler/lua51.can

@@ -22,11 +22,17 @@ tags.Break = ()
 end
 
 -- Unsuported features
-tags.Goto = nil
-tags.Label = nil
+tags.Goto = ()
+	error("target "..targetName.." does not support gotos")
+end
+tags.Label = ()
+	error("target "..targetName.." does not support goto labels")
+end
+
+#placeholder("patch")
 
 #local patch = output
 #output = ""
-#import("compiler.luajit", { patch = patch, loadPackage = false })
+#import("compiler.luajit", { preprocessorEnv = { patch = patch }, loadPackage = false })
 
 return luajit

compiler/lua52.can

@@ -0,0 +1,35 @@
+targetName = "Lua 5.2"
+
+APPEND = (t, toAppend)
+	return "do" .. indent() .. "local "..var("a")..", "..var("p").." = { " .. toAppend .. " }, #" .. t .. "+1" .. newline() .. "for i=1, #"..var("a").." do" .. indent() .. t .. "["..var("p").."] = "..var("a").."[i]" .. newline() .. ""..var("p").." = "..var("p").." + 1" .. unindent() .. "end" .. unindent() .. "end"
+end
+
+tags._opid.idiv = (left, right)
+	return "math.floor(" .. lua(left) .. " / " .. lua(right) .. ")"
+end
+tags._opid.band = (left, right)
+	return "bit32.band(" .. lua(left) .. ", " .. lua(right) .. ")"
+end
+tags._opid.bor = (left, right)
+	return "bit32.bor(" .. lua(left) .. ", " .. lua(right) .. ")"
+end
+tags._opid.bxor = (left, right)
+	return "bit32.bxor(" .. lua(left) .. ", " .. lua(right) .. ")"
+end
+tags._opid.shl = (left, right)
+	return "bit32.lshift(" .. lua(left) .. ", " .. lua(right) .. ")"
+end
+tags._opid.shr = (left, right)
+	return "bit32.rshift(" .. lua(left) .. ", " .. lua(right) .. ")"
+end
+tags._opid.bnot = (right)
+	return "bit32.bnot(" .. lua(right) .. ")"
+end
+
+#placeholder("patch")
+
+#local patch = output
+#output = ""
+#import("compiler.lua53", { preprocessorEnv = { patch = patch }, loadPackage = false })
+
+return lua53

compiler/lua53.can

@@ -1,827 +1,18 @@
-local targetName = "Lua 5.3"
+targetName = "Lua 5.3"
 
-return function(code, ast, options)
-	--- Line mapping
-	local lastInputPos = 1 -- last token position in the input code
-	local prevLinePos = 1 -- last token position in the previous line of code in the input code
-	local lastSource = options.chunkname or "nil" -- last found code source name (from the original file)
-	local lastLine = 1 -- last found line number (from the original file)
-
-	--- Newline management
-	local indentLevel = 0
-	-- Returns a newline.
-	local function newline()
-		local r = options.newline..string.rep(options.indentation, indentLevel)
-		if options.mapLines then
-			local sub = code:sub(lastInputPos)
-			local source, line = sub:sub(1, sub:find("\n")):match(".*%-%- (.-)%:(%d+)\n")
-
-			if source and line then
-				lastSource = source
-				lastLine = tonumber(line)
+-- Unsuported features
+tags.AttributeId = (t)
+	if t[2] then
+		error("target "..targetName.." does not support variable attributes")
 	else
-				for _ in code:sub(prevLinePos, lastInputPos):gmatch("\n") do
-					lastLine += 1
-				end
-			end
-
-			prevLinePos = lastInputPos
-
-			r = " -- "..lastSource..":"..lastLine..r
-		end
-		return r
-	end
-	-- Returns a newline and add one level of indentation.
-	local function indent()
-		indentLevel += 1
-		return newline()
-	end
-	-- Returns a newline and remove one level of indentation.
-	local function unindent()
-		indentLevel -= 1
-		return newline()
-	end
-
-	--- State stacks
-	-- Used for context-sensitive syntax.
-	local states = {
-		push = {}, -- push stack variable names
-		destructuring = {}, -- list of variable that need to be assigned from a destructure {id = "parent variable", "field1", "field2"...}
-		scope = {} -- list of variables defined in the current scope
-	}
-	-- Push a new value on top of the stack "name". Returns an empty string for chaining.
-	local function push(name, state)
-		table.insert(states[name], state)
-		return ""
-	end
-	-- Remove the value on top of the stack "name". Returns an empty string for chaining.
-	local function pop(name)
-		table.remove(states[name])
-		return ""
-	end
-	-- Set the value on top of the stack "name". Returns an empty string for chaining.
-	local function set(name, state)
-		states[name][#states[name]] = state
-		return ""
-	end
-	-- Returns the value on top of the stack "name".
-	local function peek(name)
-		return states[name][#states[name]]
-	end
-
-	--- Variable management
-	-- Returns the prefixed variable name.
-	local function var(name)
-		return options.variablePrefix..name
-	end
-
-	-- Returns the prefixed temporary variable name.
-	local function tmp()
-		local scope = peek("scope")
-		local var = "%s_%s":format(options.variablePrefix, #scope)
-		table.insert(scope, var)
-		return var
-	end
-
-	--- Module management
-	local required = {} -- { ["full require expression"] = true, ... }
-	local requireStr = ""
-	-- Add the module "mod" to the list of modules to require, and load its field "field" (or the whole module if nil) into the variable "name".
-	local function addRequire(mod, name, field)
-		local req = "require(%q)%s":format(mod, field and "."..field or "")
-		if not required[req] then
-			requireStr ..= "local %s = %s%s":format(var(name), req, options.newline)
-			required[req] = true
-		end
-	end
-
-	--- AST traversal helpers
-	local loop = { "While", "Repeat", "Fornum", "Forin", "WhileExpr", "RepeatExpr", "FornumExpr", "ForinExpr" } -- loops tags (can contain continue)
-	local func = { "Function", "TableCompr", "DoExpr", "WhileExpr", "RepeatExpr", "IfExpr", "FornumExpr", "ForinExpr" } -- function scope tags (can contain push)
-
-	-- Returns the first node or subnode from the list "list" which tag is in the list "tags", or nil if there were none.
-	-- Won't recursively follow nodes which have a tag in "nofollow".
-	local function any(list, tags, nofollow={})
-		local tagsCheck = {}
-		for _, tag in ipairs(tags) do
-			tagsCheck[tag] = true
-		end
-		local nofollowCheck = {}
-		for _, tag in ipairs(nofollow) do
-			nofollowCheck[tag] = true
-		end
-		for _, node in ipairs(list) do
-			if type(node) == "table" then
-				if tagsCheck[node.tag] then
-					return node
-				end
-				if not nofollowCheck[node.tag] then
-					local r = any(node, tags, nofollow)
-					if r then return r end
-				end
-			end
-		end
-		return nil
-	end
-
-	-- Like any, but returns a list of every node found.
-	-- Order: in the order of the list, from the deepest to the nearest
-	local function search(list, tags, nofollow={})
-		local tagsCheck = {}
-		for _, tag in ipairs(tags) do
-			tagsCheck[tag] = true
-		end
-		local nofollowCheck = {}
-		for _, tag in ipairs(nofollow) do
-			nofollowCheck[tag] = true
-		end
-		local found = {}
-		for _, node in ipairs(list) do
-			if type(node) == "table" then
-				if not nofollowCheck[node.tag] then
-					for _, n in ipairs(search(node, tags, nofollow)) do
-						table.insert(found, n)
-					end
-				end
-				if tagsCheck[node.tag] then
-					table.insert(found, node)
-				end
-			end
-		end
-		return found
-	end
-
-	-- Returns true if the all the nodes in list have their type in tags.
-	local function all(list, tags)
-		for _, node in ipairs(list) do
-			local ok = false
-			for _, tag in ipairs(tags) do
-				if node.tag == tag then
-					ok = true
-					break
-				end
-			end
-			if not ok then
-				return false
-			end
-		end
-		return true
-	end
-
-	--- Lua compiler
-	local tags
-	-- Recursively returns the compiled AST Lua code, set "forceTag" to override the tag type and pass additional arguments to the tag constructor if needed.
-	local function lua(ast, forceTag, ...)
-		if options.mapLines and ast.pos then
-			lastInputPos = ast.pos
-		end
-		return tags[forceTag or ast.tag](ast, ...)
-	end
-
-	--- Lua function calls writer
-	local UNPACK = (list, i, j) -- table.unpack
-		return "table.unpack("..list..(i and (", "..i..(j and (", "..j) or "")) or "")..")"
-	end
-	local APPEND = (t, toAppend) -- append values "toAppend" (multiple values possible) to t
-		return "do"..indent().."local "..var("a").." = table.pack("..toAppend..")"..newline().."table.move("..var("a")..", 1, "..var("a")..".n, #"..t.."+1, "..t..")"..unindent().."end"
-	end
-	local CONTINUE_START = () -- at the start of loops using continue
-		return "do"..indent()
-	end
-	local CONTINUE_STOP = () -- at the start of loops using continue
-		return unindent().."end"..newline().."::"..var"continue".."::"
-	end
-	local DESTRUCTURING_ASSIGN = (destructured, newlineAfter=false, noLocal=false) -- to define values from a destructuring assignement
-		local vars = {}
-		local values = {}
-		for _, list in ipairs(destructured) do
-			for _, v in ipairs(list) do
-				local var, val
-				if v.tag == "Id" then
-					var = v
-					val = { tag = "Index", { tag = "Id", list.id }, { tag = "String", v[1] } }
-				elseif v.tag == "Pair" then
-					var = v[2]
-					val = { tag = "Index", { tag = "Id", list.id }, v[1] }
-				else
-					error("unknown destructuring element type: "..tostring(v.tag))
-				end
-				if destructured.rightOp and destructured.leftOp then
-					val = { tag = "Op", destructured.rightOp, var, { tag = "Op", destructured.leftOp, val, var } }
-				elseif destructured.rightOp then
-					val = { tag = "Op", destructured.rightOp, var, val }
-				elseif destructured.leftOp then
-					val = { tag = "Op", destructured.leftOp, val, var }
-				end
-				table.insert(vars, lua(var))
-				table.insert(values, lua(val))
-			end
-		end
-		if #vars > 0 then
-			local decl = noLocal and "" or "local "
-			if newlineAfter then
-				return decl..table.concat(vars, ", ").." = "..table.concat(values, ", ")..newline()
-			else
-				return newline()..decl..table.concat(vars, ", ").." = "..table.concat(values, ", ")
-			end
-		else
-			return ""
-		end
-	end
-
-	--- Tag constructors
-	tags = setmetatable({
-		-- block: { stat* } --
-		Block = (t)
-			local hasPush = peek("push") == nil and any(t, { "Push" }, func) -- push in block and push context not yet defined
-			if hasPush and hasPush == t[#t] then -- if the first push is the last statement, it's just a return
-				hasPush.tag = "Return"
-				hasPush = false
-			end
-			local r = push("scope", {})
-			if hasPush then
-				r ..= push("push", var"push").."local "..var"push".." = {}"..newline()
-			end
-			for i=1, #t-1, 1 do
-				r ..= lua(t[i])..newline()
-			end
-			if t[#t] then
-				r ..= lua(t[#t])
-			end
-			if hasPush and (t[#t] and t[#t].tag ~= "Return") then -- add return only if needed
-				r ..= newline().."return "..UNPACK(var"push")..pop("push")
-			end
-			return r..pop("scope")
-		end,
-
-		-- stat --
-
-		-- Do{ stat* }
-		Do = (t)
-			return "do"..indent()..lua(t, "Block")..unindent().."end"
-		end,
-		-- Set{ {lhs+} (opid? = opid?)? {expr+} }
-		Set = (t)
-			-- extract vars and values
-			local expr = t[#t]
-			local vars, values = {}, {}
-			local destructuringVars, destructuringValues = {}, {}
-			for i, n in ipairs(t[1]) do
-				if n.tag == "DestructuringId" then
-					table.insert(destructuringVars, n)
-					table.insert(destructuringValues, expr[i])
-				else
-					table.insert(vars, n)
-					table.insert(values, expr[i])
-				end
-			end
-			--
-			if #t == 2 or #t == 3 then
-				local r = ""
-				if #vars > 0 then
-					r = lua(vars, "_lhs").." = "..lua(values, "_lhs")
-				end
-				if #destructuringVars > 0 then
-					local destructured = {}
-					r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
-					return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
-				end
-				return r
-			elseif #t == 4 then
-				if t[3] == "=" then
-					local r = ""
-					if #vars > 0 then
-						r ..= lua(vars, "_lhs").." = "..lua({ t[2], vars[1], { tag = "Paren", values[1] } }, "Op")
-						for i=2, math.min(#t[4], #vars), 1 do
-							r ..= ", "..lua({ t[2], vars[i], { tag = "Paren", values[i] } }, "Op")
-						end
-					end
-					if #destructuringVars > 0 then
-						local destructured = { rightOp = t[2] }
-						r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
-						return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
-					end
-					return r
-				else
-					local r  = ""
-					if #vars > 0 then
-						r ..= lua(vars, "_lhs").." = "..lua({ t[3], { tag = "Paren", values[1] }, vars[1] }, "Op")
-						for i=2, math.min(#t[4], #t[1]), 1 do
-							r ..= ", "..lua({ t[3], { tag = "Paren", values[i] }, vars[i] }, "Op")
-						end
-					end
-					if #destructuringVars > 0 then
-						local destructured = { leftOp = t[3] }
-						r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
-						return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
-					end
-					return r
-				end
-			else -- You are mad.
-				local r = ""
-				if #vars > 0 then
-					r ..= lua(vars, "_lhs").." = "..lua({ t[2], vars[1], { tag = "Op", t[4], { tag = "Paren", values[1] }, vars[1] } }, "Op")
-					for i=2, math.min(#t[5], #t[1]), 1 do
-						r ..= ", "..lua({ t[2], vars[i], { tag = "Op", t[4], { tag = "Paren", values[i] }, vars[i] } }, "Op")
-					end
-				end
-				if #destructuringVars > 0 then
-					local destructured = { rightOp = t[2], leftOp = t[4] }
-					r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
-					return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
-				end
-				return r
-			end
-		end,
-		-- While{ expr block }
-		While = (t)
-			local r = ""
-			local hasContinue = any(t[2], { "Continue" }, loop)
-			local lets = search({ t[1] }, { "LetExpr" })
-			if #lets > 0 then
-				r ..= "do"..indent()
-				for _, l in ipairs(lets) do
-					r ..= lua(l, "Let")..newline()
-				end
-			end
-			r ..= "while "..lua(t[1]).." do"..indent()
-			if #lets > 0 then
-				r ..= "do"..indent()
-			end
-			if hasContinue then
-				r ..= CONTINUE_START()
-			end
-			r ..= lua(t[2])
-			if hasContinue then
-				r ..= CONTINUE_STOP()
-			end
-			r ..= unindent().."end"
-			if #lets > 0 then
-				for _, l in ipairs(lets) do
-					r ..= newline()..lua(l, "Set")
-				end
-				r ..= unindent().."end"..unindent().."end"
-			end
-			return r
-		end,
-		-- Repeat{ block expr }
-		Repeat = (t)
-			local hasContinue = any(t[1], { "Continue" }, loop)
-			local r = "repeat"..indent()
-			if hasContinue then
-				r ..= CONTINUE_START()
-			end
-			r ..= lua(t[1])
-			if hasContinue then
-				r ..= CONTINUE_STOP()
-			end
-			r ..= unindent().."until "..lua(t[2])
-			return r
-		end,
-		-- If{ (lexpr block)+ block? }
-		If = (t)
-			local r = ""
-			local toClose = 0 -- blocks that need to be closed at the end of the if
-			local lets = search({ t[1] }, { "LetExpr" })
-			if #lets > 0 then
-				r ..= "do"..indent()
-				toClose += 1
-				for _, l in ipairs(lets) do
-					r ..= lua(l, "Let")..newline()
-				end
-			end
-			r ..= "if "..lua(t[1]).." then"..indent()..lua(t[2])..unindent()
-			for i=3, #t-1, 2 do
-				lets = search({ t[i] }, { "LetExpr" })
-				if #lets > 0 then
-					r ..= "else"..indent()
-					toClose += 1
-					for _, l in ipairs(lets) do
-						r ..= lua(l, "Let")..newline()
-					end
-				else
-					r ..= "else"
-				end
-				r ..= "if "..lua(t[i]).." then"..indent()..lua(t[i+1])..unindent()
-			end
-			if #t % 2 == 1 then
-				r ..= "else"..indent()..lua(t[#t])..unindent()
-			end
-			r ..= "end"
-			for i=1, toClose do
-				r ..= unindent().."end"
-			end
-			return r
-		end,
-		-- Fornum{ ident expr expr expr? block }
-		Fornum = (t)
-			local r = "for "..lua(t[1]).." = "..lua(t[2])..", "..lua(t[3])
-			if #t == 5 then
-				local hasContinue = any(t[5], { "Continue" }, loop)
-				r ..= ", "..lua(t[4]).." do"..indent()
-				if hasContinue then
-					r ..= CONTINUE_START()
-				end
-				r ..= lua(t[5])
-				if hasContinue then
-					r ..= CONTINUE_STOP()
-				end
-				return r..unindent().."end"
-			else
-				local hasContinue = any(t[4], { "Continue" }, loop)
-				r ..= " do"..indent()
-				if hasContinue then
-					r ..= CONTINUE_START()
-				end
-				r ..= lua(t[4])
-				if hasContinue then
-					r ..= CONTINUE_STOP()
-				end
-				return r..unindent().."end"
-			end
-		end,
-		-- Forin{ {ident+} {expr+} block }
-		Forin = (t)
-			local destructured = {}
-			local hasContinue = any(t[3], { "Continue" }, loop)
-			local r = "for "..push("destructuring", destructured)..lua(t[1], "_lhs")..pop("destructuring").." in "..lua(t[2], "_lhs").." do"..indent()
-			if hasContinue then
-				r ..= CONTINUE_START()
-			end
-			r ..= DESTRUCTURING_ASSIGN(destructured, true)..lua(t[3])
-			if hasContinue then
-				r ..= CONTINUE_STOP()
-			end
-			return r..unindent().."end"
-		end,
-		-- Local{ {ident+} {expr+}? }
-		Local = (t)
-			local destructured = {}
-			local r = "local "..push("destructuring", destructured)..lua(t[1], "_lhs")..pop("destructuring")
-			if t[2][1] then
-				r ..= " = "..lua(t[2], "_lhs")
-			end
-			return r..DESTRUCTURING_ASSIGN(destructured)
-		end,
-		-- Let{ {ident+} {expr+}? }
-		Let = (t)
-			local destructured = {}
-			local nameList = push("destructuring", destructured)..lua(t[1], "_lhs")..pop("destructuring")
-			local r = "local "..nameList
-			if t[2][1] then
-				if all(t[2], { "Nil", "Dots", "Boolean", "Number", "String" }) then -- predeclaration doesn't matter here
-					r ..= " = "..lua(t[2], "_lhs")
-				else
-					r ..= newline()..nameList.." = "..lua(t[2], "_lhs")
-				end
-			end
-			return r..DESTRUCTURING_ASSIGN(destructured)
-		end,
-		-- Localrec{ {ident} {expr} }
-		Localrec = (t)
-			return "local function "..lua(t[1][1])..lua(t[2][1], "_functionWithoutKeyword")
-		end,
-		-- Goto{ <string> }
-		Goto = (t)
-			return "goto "..lua(t, "Id")
-		end,
-		-- Label{ <string> }
-		Label = (t)
-			return "::"..lua(t, "Id").."::"
-		end,
-		-- Return{ <expr*> }
-		Return = (t)
-			local push = peek("push")
-			if push then
-				local r = ""
-				for _, val in ipairs(t) do
-					r ..= push.."[#"..push.."+1] = "..lua(val)..newline()
-				end
-				return r.."return "..UNPACK(push)
-			else
-				return "return "..lua(t, "_lhs")
-			end
-		end,
-		-- Push{ <expr*> }
-		Push = (t)
-			local var = assert(peek("push"), "no context given for push")
-			r = ""
-			for i=1, #t-1, 1 do
-				r ..= var.."[#"..var.."+1] = "..lua(t[i])..newline()
-			end
-			if t[#t] then
-				if t[#t].tag == "Call" then
-					r ..= APPEND(var, lua(t[#t]))
-				else
-					r ..= var.."[#"..var.."+1] = "..lua(t[#t])
-				end
-			end
-			return r
-		end,
-		-- Break
-		Break = ()
-			return "break"
-		end,
-		-- Continue
-		Continue = ()
-			return "goto "..var"continue"
-		end,
-		-- apply (below)
-
-		-- expr --
-
-		-- Nil
-		Nil = ()
-			return "nil"
-		end,
-		-- Dots
-		Dots = ()
-			return "..."
-		end,
-		-- Boolean{ <boolean> }
-		Boolean = (t)
-			return tostring(t[1])
-		end,
-		-- Number{ <string> }
-		Number = (t)
-			return tostring(t[1])
-		end,
-		-- String{ <string> }
-		String = (t)
-			return "%q":format(t[1])
-		end,
-		-- Function{ { ( `ParPair{ Id expr } | `Id{ <string> } )* `Dots? } block }
-		_functionWithoutKeyword = (t)
-			local r = "("
-			local decl = {}
-			if t[1][1] then
-				if t[1][1].tag == "ParPair" then
-					local id = lua(t[1][1][1])
-					indentLevel += 1
-					table.insert(decl, "if "..id.." == nil then "..id.." = "..lua(t[1][1][2]).." end")
-					indentLevel -= 1
-					r ..= id
-				else
-					r ..= lua(t[1][1])
-				end
-				for i=2, #t[1], 1 do
-					if t[1][i].tag == "ParPair" then
-						local id = lua(t[1][i][1])
-						indentLevel += 1
-						table.insert(decl, "if "..id.." == nil then "..id.." = "..lua(t[1][i][2]).." end")
-						indentLevel -= 1
-						r ..= ", " ..id
-					else
-						r ..= ", "..lua(t[1][i])
-					end
-				end
-			end
-			r ..= ")"..indent()
-			for _, d in ipairs(decl) do
-				r ..= d..newline()
-			end
-			if t[2][#t[2]] and t[2][#t[2]].tag == "Push" then -- convert final push to return
-				t[2][#t[2]].tag = "Return"
-			end
-			local hasPush = any(t[2], { "Push" }, func)
-			if hasPush then
-				r ..= push("push", var"push").."local "..var"push".." = {}"..newline()
-			else
-				push("push", false) -- no push here (make sure higher push doesn't affect us)
-			end
-			r ..= lua(t[2])
-			if hasPush and (t[2][#t[2]] and t[2][#t[2]].tag ~= "Return") then -- add return only if needed
-				r ..= newline().."return "..UNPACK(var"push")
-			end
-			pop("push")
-			return r..unindent().."end"
-		end,
-		Function = (t)
-			return "function"..lua(t, "_functionWithoutKeyword")
-		end,
-		-- Table{ ( `Pair{ expr expr } | expr )* }
-		Pair = (t)
-			return "["..lua(t[1]).."] = "..lua(t[2])
-		end,
-		Table = (t)
-			if #t == 0 then
-				return "{}"
-			elseif #t == 1 then
-				return "{ "..lua(t, "_lhs").." }"
-			else
-				return "{"..indent()..lua(t, "_lhs", nil, true)..unindent().."}"
-			end
-		end,
-		-- TableCompr{ block }
-		TableCompr = (t)
-			return push("push", "self").."(function()"..indent().."local self = {}"..newline()..lua(t[1])..newline().."return self"..unindent().."end)()"..pop("push")
-		end,
-		-- Op{ opid expr expr? }
-		Op = (t)
-			local r
-			if #t == 2 then
-				if type(tags._opid[t[1]]) == "string" then
-					r = tags._opid[t[1]].." "..lua(t[2])
-				else
-					r = tags._opid[t[1]](t[2])
-				end
-			else
-				if type(tags._opid[t[1]]) == "string" then
-					r = lua(t[2]).." "..tags._opid[t[1]].." "..lua(t[3])
-				else
-					r = tags._opid[t[1]](t[2], t[3])
-				end
-			end
-			return r
-		end,
-		-- Paren{ expr }
-		Paren = (t)
-			return "("..lua(t[1])..")"
-		end,
-		-- MethodStub{ expr expr }
-		MethodStub = (t)
-			return "(function()"..indent() ..
-					"local "..var"object".." = "..lua(t[1])..newline()..
-					"local "..var"method".." = "..var"object".."."..lua(t[2], "Id")..newline() ..
-					"if "..var"method".." == nil then return nil end"..newline()..
-					"return function(...) return "..var"method".."("..var"object"..", ...) end"..unindent()..
-				"end)()"
-		end,
-		-- SafeMethodStub{ expr expr }
-		SafeMethodStub = (t)
-			return "(function()"..indent() ..
-					"local "..var"object".." = "..lua(t[1])..newline()..
-					"if "..var"object".." == nil then return nil end"..newline()..
-					"local "..var"method".." = "..var"object".."."..lua(t[2], "Id")..newline() ..
-					"if "..var"method".." == nil then return nil end"..newline()..
-					"return function(...) return "..var"method".."("..var"object"..", ...) end"..unindent()..
-				"end)()"
-		end,
-		-- statexpr (below)
-		-- apply (below)
-		-- lhs (below)
-
-		-- lexpr --
-		LetExpr = (t)
-			return lua(t[1][1])
-		end,
-
-		-- statexpr --
-		_statexpr = (t, stat)
-			local hasPush = any(t, { "Push" }, func)
-			local r = "(function()"..indent()
-			if hasPush then
-				r ..= push("push", var"push").."local "..var"push".." = {}"..newline()
-			else
-				push("push", false) -- no push here (make sure higher push don't affect us)
-			end
-			r ..= lua(t, stat)
-			if hasPush then
-				r ..= newline().."return "..UNPACK(var"push")
-			end
-			pop("push")
-			r ..= unindent().."end)()"
-			return r
-		end,
-		-- DoExpr{ stat* }
-		DoExpr = (t)
-			if t[#t].tag == "Push" then -- convert final push to return
-				t[#t].tag = "Return"
-			end
-			return lua(t, "_statexpr", "Do")
-		end,
-		-- WhileExpr{ expr block }
-		WhileExpr = (t)
-			return lua(t, "_statexpr", "While")
-		end,
-		-- RepeatExpr{ block expr }
-		RepeatExpr = (t)
-			return lua(t, "_statexpr", "Repeat")
-		end,
-		-- IfExpr{ (expr block)+ block? }
-		IfExpr = (t)
-			for i=2, #t do -- convert final pushes to returns
-				local block = t[i]
-				if block[#block] and block[#block].tag == "Push" then
-					block[#block].tag = "Return"
-				end
-			end
-			return lua(t, "_statexpr", "If")
-		end,
-		-- FornumExpr{ ident expr expr expr? block }
-		FornumExpr = (t)
-			return lua(t, "_statexpr", "Fornum")
-		end,
-		-- ForinExpr{ {ident+} {expr+} block }
-		ForinExpr = (t)
-			return lua(t, "_statexpr", "Forin")
-		end,
-
-		-- apply --
-
-		-- Call{ expr expr* }
-		Call = (t)
-			if t[1].tag == "String" or t[1].tag == "Table" then
-				return "("..lua(t[1])..")("..lua(t, "_lhs", 2)..")"
-			elseif t[1].tag == "MethodStub" then -- method call
-				if t[1][1].tag == "String" or t[1][1].tag == "Table" then
-					return "("..lua(t[1][1]).."):"..lua(t[1][2], "Id").."("..lua(t, "_lhs", 2)..")"
-				else
-					return lua(t[1][1])..":"..lua(t[1][2], "Id").."("..lua(t, "_lhs", 2)..")"
-				end
-			else
-				return lua(t[1]).."("..lua(t, "_lhs", 2)..")"
-			end
-		end,
-		-- SafeCall{ expr expr* }
-		SafeCall = (t)
-			if t[1].tag ~= "Id" then -- side effect possible, only evaluate each expr once (or already in a safe context)
-				return lua(t, "SafeIndex")
-			else -- no side effects possible
-				return "("..lua(t[1]).." ~= nil and "..lua(t[1]).."("..lua(t, "_lhs", 2)..") or nil)"
-			end
-		end,
-
-		-- lhs --
-		_lhs = (t, start=1, newlines)
-			local r
-			if t[start] then
-				r = lua(t[start])
-				for i=start+1, #t, 1 do
-					r ..= ","..(newlines and newline() or " ")..lua(t[i])
-				end
-			else
-				r = ""
-			end
-			return r
-		end,
-		-- Id{ <string> }
-		Id = (t)
 		return t[1]
-		end,
-		-- DestructuringId{ Id | Pair+ }
-		DestructuringId = (t)
-			if t.id then -- destructing already done before, use parent variable as id
-				return t.id
-			else
-				local d = assert(peek("destructuring"), "DestructuringId not in a destructurable assignement")
-				local vars = { id = tmp() }
-				for j=1, #t, 1 do
-					table.insert(vars, t[j])
-				end
-				table.insert(d, vars)
-				t.id = vars.id
-				return vars.id
-			end
-		end,
-		-- Index{ expr expr }
-		Index = (t)
-			if t[1].tag == "String" or t[1].tag == "Table" then
-				return "("..lua(t[1])..")["..lua(t[2]).."]"
-			else
-				return lua(t[1]).."["..lua(t[2]).."]"
-			end
-		end,
-		-- SafeIndex{ expr expr }
-		SafeIndex = (t)
-			if t[1].tag ~= "Id" then -- side effect possible, only evaluate each expr once (or already in a safe context)
-				local l = {} -- list of immediately chained safeindex, from deepest to nearest (to simply generated code)
-				while t.tag == "SafeIndex" or t.tag == "SafeCall" do
-					table.insert(l, 1, t)
-					t = t[1]
-				end
-				local r = "(function()"..indent().."local "..var"safe".." = "..lua(l[1][1])..newline() -- base expr
-				for _, e in ipairs(l) do
-					r ..= "if "..var"safe".." == nil then return nil end"..newline()
-					if e.tag == "SafeIndex" then
-						r ..= var"safe".." = "..var"safe".."["..lua(e[2]).."]"..newline()
-					else
-						r ..= var"safe".." = "..var"safe".."("..lua(e, "_lhs", 2)..")"..newline()
 	end
 end
-				r ..= "return "..var"safe"..unindent().."end)()"
-				return r
-			else -- no side effects possible
-				return "("..lua(t[1]).." ~= nil and "..lua(t[1]).."["..lua(t[2]).."] or nil)"
-			end
-		end,
-
-		-- opid --
-		_opid = {
-			add = "+", sub = "-", mul = "*", div = "/",
-			idiv = "//", mod = "%", pow = "^", concat = "..",
-			band = "&", bor = "|", bxor = "~", shl = "<<", shr = ">>",
-			eq = "==", ne = "~=", lt = "<", gt = ">", le = "<=", ge = ">=",
-			["and"] = "and", ["or"] = "or", unm = "-", len = "#", bnot = "~", ["not"] = "not"
-		}
-	}, {
-		__index = (self, key)
-			error("don't know how to compile a "..tostring(key).." to "..targetName)
-		end
-	})
 
 #placeholder("patch")
 
-	local code = lua(ast)..newline()
-	return requireStr..code
-end
+#local patch = output
+#output = ""
+#import("compiler.lua54", { preprocessorEnv = { patch = patch }, loadPackage = false })
+
+return lua54

compiler/lua54.can

@@ -0,0 +1,898 @@
+local util = require("candran.util")
+
+local targetName = "Lua 5.4"
+
+local unpack = unpack or table.unpack
+
+return function(code, ast, options, macros={functions={}, variables={}})
+	--- Line mapping
+	local lastInputPos = 1 -- last token position in the input code
+	local prevLinePos = 1 -- last token position in the previous line of code in the input code
+	local lastSource = options.chunkname or "nil" -- last found code source name (from the original file)
+	local lastLine = 1 -- last found line number (from the original file)
+
+	--- Newline management
+	local indentLevel = 0
+	-- Returns a newline.
+	local function newline()
+		local r = options.newline..string.rep(options.indentation, indentLevel)
+		if options.mapLines then
+			local sub = code:sub(lastInputPos)
+			local source, line = sub:sub(1, sub:find("\n")):match(".*%-%- (.-)%:(%d+)\n")
+
+			if source and line then
+				lastSource = source
+				lastLine = tonumber(line)
+			else
+				for _ in code:sub(prevLinePos, lastInputPos):gmatch("\n") do
+					lastLine += 1
+				end
+			end
+
+			prevLinePos = lastInputPos
+
+			r = " -- "..lastSource..":"..lastLine..r
+		end
+		return r
+	end
+	-- Returns a newline and add one level of indentation.
+	local function indent()
+		indentLevel += 1
+		return newline()
+	end
+	-- Returns a newline and remove one level of indentation.
+	local function unindent()
+		indentLevel -= 1
+		return newline()
+	end
+
+	--- State stacks
+	-- Used for context-sensitive syntax.
+	local states = {
+		push = {}, -- push stack variable names
+		destructuring = {}, -- list of variable that need to be assigned from a destructure {id = "parent variable", "field1", "field2"...}
+		scope = {}, -- list of variables defined in the current scope
+		macroargs = {} -- currently defined arguemnts from a macro function
+	}
+	-- Push a new value on top of the stack "name". Returns an empty string for chaining.
+	local function push(name, state)
+		table.insert(states[name], state)
+		return ""
+	end
+	-- Remove the value on top of the stack "name". Returns an empty string for chaining.
+	local function pop(name)
+		table.remove(states[name])
+		return ""
+	end
+	-- Set the value on top of the stack "name". Returns an empty string for chaining.
+	local function set(name, state)
+		states[name][#states[name]] = state
+		return ""
+	end
+	-- Returns the value on top of the stack "name".
+	local function peek(name)
+		return states[name][#states[name]]
+	end
+
+	--- Variable management
+	-- Returns the prefixed variable name.
+	local function var(name)
+		return options.variablePrefix..name
+	end
+
+	-- Returns the prefixed temporary variable name.
+	local function tmp()
+		local scope = peek("scope")
+		local var = "%s_%s":format(options.variablePrefix, #scope)
+		table.insert(scope, var)
+		return var
+	end
+
+	-- indicate if currently processing a macro, so it cannot be applied recursively
+	local nomacro = { variables = {}, functions = {} }
+
+	--- Module management
+	local required = {} -- { ["full require expression"] = true, ... }
+	local requireStr = ""
+	-- Add the module "mod" to the list of modules to require, and load its field "field" (or the whole module if nil) into the variable "name".
+	local function addRequire(mod, name, field)
+		local req = "require(%q)%s":format(mod, field and "."..field or "")
+		if not required[req] then
+			requireStr ..= "local %s = %s%s":format(var(name), req, options.newline)
+			required[req] = true
+		end
+	end
+
+	--- AST traversal helpers
+	local loop = { "While", "Repeat", "Fornum", "Forin", "WhileExpr", "RepeatExpr", "FornumExpr", "ForinExpr" } -- loops tags (can contain continue)
+	local func = { "Function", "TableCompr", "DoExpr", "WhileExpr", "RepeatExpr", "IfExpr", "FornumExpr", "ForinExpr" } -- function scope tags (can contain push)
+
+	-- Returns the first node or subnode from the list "list" which tag is in the list "tags", or nil if there were none.
+	-- Won't recursively follow nodes which have a tag in "nofollow".
+	local function any(list, tags, nofollow={})
+		local tagsCheck = {}
+		for _, tag in ipairs(tags) do
+			tagsCheck[tag] = true
+		end
+		local nofollowCheck = {}
+		for _, tag in ipairs(nofollow) do
+			nofollowCheck[tag] = true
+		end
+		for _, node in ipairs(list) do
+			if type(node) == "table" then
+				if tagsCheck[node.tag] then
+					return node
+				end
+				if not nofollowCheck[node.tag] then
+					local r = any(node, tags, nofollow)
+					if r then return r end
+				end
+			end
+		end
+		return nil
+	end
+
+	-- Like any, but returns a list of every node found.
+	-- Order: in the order of the list, from the deepest to the nearest
+	local function search(list, tags, nofollow={})
+		local tagsCheck = {}
+		for _, tag in ipairs(tags) do
+			tagsCheck[tag] = true
+		end
+		local nofollowCheck = {}
+		for _, tag in ipairs(nofollow) do
+			nofollowCheck[tag] = true
+		end
+		local found = {}
+		for _, node in ipairs(list) do
+			if type(node) == "table" then
+				if not nofollowCheck[node.tag] then
+					for _, n in ipairs(search(node, tags, nofollow)) do
+						table.insert(found, n)
+					end
+				end
+				if tagsCheck[node.tag] then
+					table.insert(found, node)
+				end
+			end
+		end
+		return found
+	end
+
+	-- Returns true if the all the nodes in list have their type in tags.
+	local function all(list, tags)
+		for _, node in ipairs(list) do
+			local ok = false
+			for _, tag in ipairs(tags) do
+				if node.tag == tag then
+					ok = true
+					break
+				end
+			end
+			if not ok then
+				return false
+			end
+		end
+		return true
+	end
+
+	--- Lua compiler
+	local tags
+	-- Recursively returns the compiled AST Lua code, set "forceTag" to override the tag type and pass additional arguments to the tag constructor if needed.
+	local function lua(ast, forceTag, ...)
+		if options.mapLines and ast.pos then
+			lastInputPos = ast.pos
+		end
+		return tags[forceTag or ast.tag](ast, ...)
+	end
+
+	--- Lua function calls writer
+	local UNPACK = (list, i, j) -- table.unpack
+		return "table.unpack("..list..(i and (", "..i..(j and (", "..j) or "")) or "")..")"
+	end
+	local APPEND = (t, toAppend) -- append values "toAppend" (multiple values possible) to t
+		return "do"..indent().."local "..var("a").." = table.pack("..toAppend..")"..newline().."table.move("..var("a")..", 1, "..var("a")..".n, #"..t.."+1, "..t..")"..unindent().."end"
+	end
+	local CONTINUE_START = () -- at the start of loops using continue
+		return "do"..indent()
+	end
+	local CONTINUE_STOP = () -- at the start of loops using continue
+		return unindent().."end"..newline().."::"..var"continue".."::"
+	end
+	local DESTRUCTURING_ASSIGN = (destructured, newlineAfter=false, noLocal=false) -- to define values from a destructuring assignement
+		local vars = {}
+		local values = {}
+		for _, list in ipairs(destructured) do
+			for _, v in ipairs(list) do
+				local var, val
+				if v.tag == "Id" or v.tag == "AttributeId" then
+					var = v
+					val = { tag = "Index", { tag = "Id", list.id }, { tag = "String", v[1] } }
+				elseif v.tag == "Pair" then
+					var = v[2]
+					val = { tag = "Index", { tag = "Id", list.id }, v[1] }
+				else
+					error("unknown destructuring element type: "..tostring(v.tag))
+				end
+				if destructured.rightOp and destructured.leftOp then
+					val = { tag = "Op", destructured.rightOp, var, { tag = "Op", destructured.leftOp, val, var } }
+				elseif destructured.rightOp then
+					val = { tag = "Op", destructured.rightOp, var, val }
+				elseif destructured.leftOp then
+					val = { tag = "Op", destructured.leftOp, val, var }
+				end
+				table.insert(vars, lua(var))
+				table.insert(values, lua(val))
+			end
+		end
+		if #vars > 0 then
+			local decl = noLocal and "" or "local "
+			if newlineAfter then
+				return decl..table.concat(vars, ", ").." = "..table.concat(values, ", ")..newline()
+			else
+				return newline()..decl..table.concat(vars, ", ").." = "..table.concat(values, ", ")
+			end
+		else
+			return ""
+		end
+	end
+
+	--- Tag constructors
+	tags = setmetatable({
+		-- block: { stat* } --
+		Block = (t)
+			local hasPush = peek("push") == nil and any(t, { "Push" }, func) -- push in block and push context not yet defined
+			if hasPush and hasPush == t[#t] then -- if the first push is the last statement, it's just a return
+				hasPush.tag = "Return"
+				hasPush = false
+			end
+			local r = push("scope", {})
+			if hasPush then
+				r ..= push("push", var"push").."local "..var"push".." = {}"..newline()
+			end
+			for i=1, #t-1, 1 do
+				r ..= lua(t[i])..newline()
+			end
+			if t[#t] then
+				r ..= lua(t[#t])
+			end
+			if hasPush and (t[#t] and t[#t].tag ~= "Return") then -- add return only if needed
+				r ..= newline().."return "..UNPACK(var"push")..pop("push")
+			end
+			return r..pop("scope")
+		end,
+
+		-- stat --
+
+		-- Do{ stat* }
+		Do = (t)
+			return "do"..indent()..lua(t, "Block")..unindent().."end"
+		end,
+		-- Set{ {lhs+} (opid? = opid?)? {expr+} }
+		Set = (t)
+			-- extract vars and values
+			local expr = t[#t]
+			local vars, values = {}, {}
+			local destructuringVars, destructuringValues = {}, {}
+			for i, n in ipairs(t[1]) do
+				if n.tag == "DestructuringId" then
+					table.insert(destructuringVars, n)
+					table.insert(destructuringValues, expr[i])
+				else
+					table.insert(vars, n)
+					table.insert(values, expr[i])
+				end
+			end
+			--
+			if #t == 2 or #t == 3 then
+				local r = ""
+				if #vars > 0 then
+					r = lua(vars, "_lhs").." = "..lua(values, "_lhs")
+				end
+				if #destructuringVars > 0 then
+					local destructured = {}
+					r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
+					return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
+				end
+				return r
+			elseif #t == 4 then
+				if t[3] == "=" then
+					local r = ""
+					if #vars > 0 then
+						r ..= lua(vars, "_lhs").." = "..lua({ t[2], vars[1], { tag = "Paren", values[1] } }, "Op")
+						for i=2, math.min(#t[4], #vars), 1 do
+							r ..= ", "..lua({ t[2], vars[i], { tag = "Paren", values[i] } }, "Op")
+						end
+					end
+					if #destructuringVars > 0 then
+						local destructured = { rightOp = t[2] }
+						r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
+						return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
+					end
+					return r
+				else
+					local r  = ""
+					if #vars > 0 then
+						r ..= lua(vars, "_lhs").." = "..lua({ t[3], { tag = "Paren", values[1] }, vars[1] }, "Op")
+						for i=2, math.min(#t[4], #t[1]), 1 do
+							r ..= ", "..lua({ t[3], { tag = "Paren", values[i] }, vars[i] }, "Op")
+						end
+					end
+					if #destructuringVars > 0 then
+						local destructured = { leftOp = t[3] }
+						r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
+						return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
+					end
+					return r
+				end
+			else -- You are mad.
+				local r = ""
+				if #vars > 0 then
+					r ..= lua(vars, "_lhs").." = "..lua({ t[2], vars[1], { tag = "Op", t[4], { tag = "Paren", values[1] }, vars[1] } }, "Op")
+					for i=2, math.min(#t[5], #t[1]), 1 do
+						r ..= ", "..lua({ t[2], vars[i], { tag = "Op", t[4], { tag = "Paren", values[i] }, vars[i] } }, "Op")
+					end
+				end
+				if #destructuringVars > 0 then
+					local destructured = { rightOp = t[2], leftOp = t[4] }
+					r ..= "local "..push("destructuring", destructured)..lua(destructuringVars, "_lhs")..pop("destructuring").." = "..lua(destructuringValues, "_lhs")
+					return r..DESTRUCTURING_ASSIGN(destructured, nil, true)
+				end
+				return r
+			end
+		end,
+		-- While{ expr block }
+		While = (t)
+			local r = ""
+			local hasContinue = any(t[2], { "Continue" }, loop)
+			local lets = search({ t[1] }, { "LetExpr" })
+			if #lets > 0 then
+				r ..= "do"..indent()
+				for _, l in ipairs(lets) do
+					r ..= lua(l, "Let")..newline()
+				end
+			end
+			r ..= "while "..lua(t[1]).." do"..indent()
+			if #lets > 0 then
+				r ..= "do"..indent()
+			end
+			if hasContinue then
+				r ..= CONTINUE_START()
+			end
+			r ..= lua(t[2])
+			if hasContinue then
+				r ..= CONTINUE_STOP()
+			end
+			r ..= unindent().."end"
+			if #lets > 0 then
+				for _, l in ipairs(lets) do
+					r ..= newline()..lua(l, "Set")
+				end
+				r ..= unindent().."end"..unindent().."end"
+			end
+			return r
+		end,
+		-- Repeat{ block expr }
+		Repeat = (t)
+			local hasContinue = any(t[1], { "Continue" }, loop)
+			local r = "repeat"..indent()
+			if hasContinue then
+				r ..= CONTINUE_START()
+			end
+			r ..= lua(t[1])
+			if hasContinue then
+				r ..= CONTINUE_STOP()
+			end
+			r ..= unindent().."until "..lua(t[2])
+			return r
+		end,
+		-- If{ (lexpr block)+ block? }
+		If = (t)
+			local r = ""
+			local toClose = 0 -- blocks that need to be closed at the end of the if
+			local lets = search({ t[1] }, { "LetExpr" })
+			if #lets > 0 then
+				r ..= "do"..indent()
+				toClose += 1
+				for _, l in ipairs(lets) do
+					r ..= lua(l, "Let")..newline()
+				end
+			end
+			r ..= "if "..lua(t[1]).." then"..indent()..lua(t[2])..unindent()
+			for i=3, #t-1, 2 do
+				lets = search({ t[i] }, { "LetExpr" })
+				if #lets > 0 then
+					r ..= "else"..indent()
+					toClose += 1
+					for _, l in ipairs(lets) do
+						r ..= lua(l, "Let")..newline()
+					end
+				else
+					r ..= "else"
+				end
+				r ..= "if "..lua(t[i]).." then"..indent()..lua(t[i+1])..unindent()
+			end
+			if #t % 2 == 1 then
+				r ..= "else"..indent()..lua(t[#t])..unindent()
+			end
+			r ..= "end"
+			for i=1, toClose do
+				r ..= unindent().."end"
+			end
+			return r
+		end,
+		-- Fornum{ ident expr expr expr? block }
+		Fornum = (t)
+			local r = "for "..lua(t[1]).." = "..lua(t[2])..", "..lua(t[3])
+			if #t == 5 then
+				local hasContinue = any(t[5], { "Continue" }, loop)
+				r ..= ", "..lua(t[4]).." do"..indent()
+				if hasContinue then
+					r ..= CONTINUE_START()
+				end
+				r ..= lua(t[5])
+				if hasContinue then
+					r ..= CONTINUE_STOP()
+				end
+				return r..unindent().."end"
+			else
+				local hasContinue = any(t[4], { "Continue" }, loop)
+				r ..= " do"..indent()
+				if hasContinue then
+					r ..= CONTINUE_START()
+				end
+				r ..= lua(t[4])
+				if hasContinue then
+					r ..= CONTINUE_STOP()
+				end
+				return r..unindent().."end"
+			end
+		end,
+		-- Forin{ {ident+} {expr+} block }
+		Forin = (t)
+			local destructured = {}
+			local hasContinue = any(t[3], { "Continue" }, loop)
+			local r = "for "..push("destructuring", destructured)..lua(t[1], "_lhs")..pop("destructuring").." in "..lua(t[2], "_lhs").." do"..indent()
+			if hasContinue then
+				r ..= CONTINUE_START()
+			end
+			r ..= DESTRUCTURING_ASSIGN(destructured, true)..lua(t[3])
+			if hasContinue then
+				r ..= CONTINUE_STOP()
+			end
+			return r..unindent().."end"
+		end,
+		-- Local{ {attributeident+} {expr+}? }
+		Local = (t)
+			local destructured = {}
+			local r = "local "..push("destructuring", destructured)..lua(t[1], "_lhs")..pop("destructuring")
+			if t[2][1] then
+				r ..= " = "..lua(t[2], "_lhs")
+			end
+			return r..DESTRUCTURING_ASSIGN(destructured)
+		end,
+		-- Let{ {ident+} {expr+}? }
+		Let = (t)
+			local destructured = {}
+			local nameList = push("destructuring", destructured)..lua(t[1], "_lhs")..pop("destructuring")
+			local r = "local "..nameList
+			if t[2][1] then
+				if all(t[2], { "Nil", "Dots", "Boolean", "Number", "String" }) then -- predeclaration doesn't matter here
+					r ..= " = "..lua(t[2], "_lhs")
+				else
+					r ..= newline()..nameList.." = "..lua(t[2], "_lhs")
+				end
+			end
+			return r..DESTRUCTURING_ASSIGN(destructured)
+		end,
+		-- Localrec{ {ident} {expr} }
+		Localrec = (t)
+			return "local function "..lua(t[1][1])..lua(t[2][1], "_functionWithoutKeyword")
+		end,
+		-- Goto{ <string> }
+		Goto = (t)
+			return "goto "..lua(t, "Id")
+		end,
+		-- Label{ <string> }
+		Label = (t)
+			return "::"..lua(t, "Id").."::"
+		end,
+		-- Return{ <expr*> }
+		Return = (t)
+			local push = peek("push")
+			if push then
+				local r = ""
+				for _, val in ipairs(t) do
+					r ..= push.."[#"..push.."+1] = "..lua(val)..newline()
+				end
+				return r.."return "..UNPACK(push)
+			else
+				return "return "..lua(t, "_lhs")
+			end
+		end,
+		-- Push{ <expr*> }
+		Push = (t)
+			local var = assert(peek("push"), "no context given for push")
+			r = ""
+			for i=1, #t-1, 1 do
+				r ..= var.."[#"..var.."+1] = "..lua(t[i])..newline()
+			end
+			if t[#t] then
+				if t[#t].tag == "Call" then
+					r ..= APPEND(var, lua(t[#t]))
+				else
+					r ..= var.."[#"..var.."+1] = "..lua(t[#t])
+				end
+			end
+			return r
+		end,
+		-- Break
+		Break = ()
+			return "break"
+		end,
+		-- Continue
+		Continue = ()
+			return "goto "..var"continue"
+		end,
+		-- apply (below)
+
+		-- expr --
+
+		-- Nil
+		Nil = ()
+			return "nil"
+		end,
+		-- Dots
+		Dots = ()
+			local macroargs = peek("macroargs")
+			if macroargs and not nomacro.variables["..."] and macroargs["..."] then
+				nomacro.variables["..."] = true
+				local r = lua(macroargs["..."], "_lhs")
+				nomacro.variables["..."] = nil
+				return r
+			else
+				return "..."
+			end
+		end,
+		-- Boolean{ <boolean> }
+		Boolean = (t)
+			return tostring(t[1])
+		end,
+		-- Number{ <string> }
+		Number = (t)
+			return tostring(t[1])
+		end,
+		-- String{ <string> }
+		String = (t)
+			return "%q":format(t[1])
+		end,
+		-- Function{ { ( `ParPair{ Id expr } | `Id{ <string> } )* `Dots? } block }
+		_functionWithoutKeyword = (t)
+			local r = "("
+			local decl = {}
+			if t[1][1] then
+				if t[1][1].tag == "ParPair" then
+					local id = lua(t[1][1][1])
+					indentLevel += 1
+					table.insert(decl, "if "..id.." == nil then "..id.." = "..lua(t[1][1][2]).." end")
+					indentLevel -= 1
+					r ..= id
+				else
+					r ..= lua(t[1][1])
+				end
+				for i=2, #t[1], 1 do
+					if t[1][i].tag == "ParPair" then
+						local id = lua(t[1][i][1])
+						indentLevel += 1
+						table.insert(decl, "if "..id.." == nil then "..id.." = "..lua(t[1][i][2]).." end")
+						indentLevel -= 1
+						r ..= ", " ..id
+					else
+						r ..= ", "..lua(t[1][i])
+					end
+				end
+			end
+			r ..= ")"..indent()
+			for _, d in ipairs(decl) do
+				r ..= d..newline()
+			end
+			if t[2][#t[2]] and t[2][#t[2]].tag == "Push" then -- convert final push to return
+				t[2][#t[2]].tag = "Return"
+			end
+			local hasPush = any(t[2], { "Push" }, func)
+			if hasPush then
+				r ..= push("push", var"push").."local "..var"push".." = {}"..newline()
+			else
+				push("push", false) -- no push here (make sure higher push doesn't affect us)
+			end
+			r ..= lua(t[2])
+			if hasPush and (t[2][#t[2]] and t[2][#t[2]].tag ~= "Return") then -- add return only if needed
+				r ..= newline().."return "..UNPACK(var"push")
+			end
+			pop("push")
+			return r..unindent().."end"
+		end,
+		Function = (t)
+			return "function"..lua(t, "_functionWithoutKeyword")
+		end,
+		-- Table{ ( `Pair{ expr expr } | expr )* }
+		Pair = (t)
+			return "["..lua(t[1]).."] = "..lua(t[2])
+		end,
+		Table = (t)
+			if #t == 0 then
+				return "{}"
+			elseif #t == 1 then
+				return "{ "..lua(t, "_lhs").." }"
+			else
+				return "{"..indent()..lua(t, "_lhs", nil, true)..unindent().."}"
+			end
+		end,
+		-- TableCompr{ block }
+		TableCompr = (t)
+			return push("push", "self").."(function()"..indent().."local self = {}"..newline()..lua(t[1])..newline().."return self"..unindent().."end)()"..pop("push")
+		end,
+		-- Op{ opid expr expr? }
+		Op = (t)
+			local r
+			if #t == 2 then
+				if type(tags._opid[t[1]]) == "string" then
+					r = tags._opid[t[1]].." "..lua(t[2])
+				else
+					r = tags._opid[t[1]](t[2])
+				end
+			else
+				if type(tags._opid[t[1]]) == "string" then
+					r = lua(t[2]).." "..tags._opid[t[1]].." "..lua(t[3])
+				else
+					r = tags._opid[t[1]](t[2], t[3])
+				end
+			end
+			return r
+		end,
+		-- Paren{ expr }
+		Paren = (t)
+			return "("..lua(t[1])..")"
+		end,
+		-- MethodStub{ expr expr }
+		MethodStub = (t)
+			return "(function()"..indent() ..
+					"local "..var"object".." = "..lua(t[1])..newline()..
+					"local "..var"method".." = "..var"object".."."..lua(t[2], "Id")..newline() ..
+					"if "..var"method".." == nil then return nil end"..newline()..
+					"return function(...) return "..var"method".."("..var"object"..", ...) end"..unindent()..
+				"end)()"
+		end,
+		-- SafeMethodStub{ expr expr }
+		SafeMethodStub = (t)
+			return "(function()"..indent() ..
+					"local "..var"object".." = "..lua(t[1])..newline()..
+					"if "..var"object".." == nil then return nil end"..newline()..
+					"local "..var"method".." = "..var"object".."."..lua(t[2], "Id")..newline() ..
+					"if "..var"method".." == nil then return nil end"..newline()..
+					"return function(...) return "..var"method".."("..var"object"..", ...) end"..unindent()..
+				"end)()"
+		end,
+		-- statexpr (below)
+		-- apply (below)
+		-- lhs (below)
+
+		-- lexpr --
+		LetExpr = (t)
+			return lua(t[1][1])
+		end,
+
+		-- statexpr --
+		_statexpr = (t, stat)
+			local hasPush = any(t, { "Push" }, func)
+			local r = "(function()"..indent()
+			if hasPush then
+				r ..= push("push", var"push").."local "..var"push".." = {}"..newline()
+			else
+				push("push", false) -- no push here (make sure higher push don't affect us)
+			end
+			r ..= lua(t, stat)
+			if hasPush then
+				r ..= newline().."return "..UNPACK(var"push")
+			end
+			pop("push")
+			r ..= unindent().."end)()"
+			return r
+		end,
+		-- DoExpr{ stat* }
+		DoExpr = (t)
+			if t[#t].tag == "Push" then -- convert final push to return
+				t[#t].tag = "Return"
+			end
+			return lua(t, "_statexpr", "Do")
+		end,
+		-- WhileExpr{ expr block }
+		WhileExpr = (t)
+			return lua(t, "_statexpr", "While")
+		end,
+		-- RepeatExpr{ block expr }
+		RepeatExpr = (t)
+			return lua(t, "_statexpr", "Repeat")
+		end,
+		-- IfExpr{ (expr block)+ block? }
+		IfExpr = (t)
+			for i=2, #t do -- convert final pushes to returns
+				local block = t[i]
+				if block[#block] and block[#block].tag == "Push" then
+					block[#block].tag = "Return"
+				end
+			end
+			return lua(t, "_statexpr", "If")
+		end,
+		-- FornumExpr{ ident expr expr expr? block }
+		FornumExpr = (t)
+			return lua(t, "_statexpr", "Fornum")
+		end,
+		-- ForinExpr{ {ident+} {expr+} block }
+		ForinExpr = (t)
+			return lua(t, "_statexpr", "Forin")
+		end,
+
+		-- apply --
+
+		-- Call{ expr expr* }
+		Call = (t)
+			if t[1].tag == "String" or t[1].tag == "Table" then
+				return "("..lua(t[1])..")("..lua(t, "_lhs", 2)..")"
+			elseif t[1].tag == "Id" and not nomacro.functions[t[1][1]] and macros.functions[t[1][1]] then
+				local macro = macros.functions[t[1][1]]
+				local replacement = macro.replacement
+				local r
+				nomacro.functions[t[1][1]] = true
+				if type(replacement) == "function" then
+					local args = {}
+					for i=2, #t do
+						table.insert(args, lua(t[i]))
+					end
+					r = replacement(unpack(args))
+				else
+					local macroargs = util.merge(peek("macroargs"))
+					for i, arg in ipairs(macro.args) do
+						if arg.tag == "Dots" then
+							macroargs["..."] = [for j=i+1, #t do t[j] end]
+						elseif arg.tag == "Id" then
+							if t[i+1] == nil then
+								error("bad argument #%s to macro %s (value expected)":format(i, t[1][1]))
+							end
+							macroargs[arg[1]] = t[i+1]
+						else
+							error("unexpected argument type %s in macro %s":format(arg.tag, t[1][1]))
+						end
+					end
+					push("macroargs", macroargs)
+					r = lua(replacement)
+					pop("macroargs")
+				end
+				nomacro.functions[t[1][1]] = nil
+				return r
+			elseif t[1].tag == "MethodStub" then -- method call
+				if t[1][1].tag == "String" or t[1][1].tag == "Table" then
+					return "("..lua(t[1][1]).."):"..lua(t[1][2], "Id").."("..lua(t, "_lhs", 2)..")"
+				else
+					return lua(t[1][1])..":"..lua(t[1][2], "Id").."("..lua(t, "_lhs", 2)..")"
+				end
+			else
+				return lua(t[1]).."("..lua(t, "_lhs", 2)..")"
+			end
+		end,
+		-- SafeCall{ expr expr* }
+		SafeCall = (t)
+			if t[1].tag ~= "Id" then -- side effect possible, only evaluate each expr once (or already in a safe context)
+				return lua(t, "SafeIndex")
+			else -- no side effects possible
+				return "("..lua(t[1]).." ~= nil and "..lua(t[1]).."("..lua(t, "_lhs", 2)..") or nil)"
+			end
+		end,
+
+		-- lhs --
+		_lhs = (t, start=1, newlines)
+			local r
+			if t[start] then
+				r = lua(t[start])
+				for i=start+1, #t, 1 do
+					r ..= ","..(newlines and newline() or " ")..lua(t[i])
+				end
+			else
+				r = ""
+			end
+			return r
+		end,
+		-- Id{ <string> }
+		Id = (t)
+			local r = t[1]
+			local macroargs = peek("macroargs")
+			if not nomacro.variables[t[1]] then
+				nomacro.variables[t[1]] = true
+				if macroargs and macroargs[t[1]] then -- replace with macro argument
+					r = lua(macroargs[t[1]])
+				elseif macros.variables[t[1]] ~= nil then -- replace with macro variable
+					local macro = macros.variables[t[1]]
+					if type(macro) == "function" then
+						r = macro()
+					else
+						r = lua(macro)
+					end
+				end
+				nomacro.variables[t[1]] = nil
+			end
+			return r
+		end,
+		-- AttributeId{ <string> <string>? }
+		AttributeId = (t)
+			if t[2] then
+				return t[1] .. " <" .. t[2] .. ">"
+			else
+				return t[1]
+			end
+		end,
+		-- DestructuringId{ Id | Pair+ }
+		DestructuringId = (t)
+			if t.id then -- destructing already done before, use parent variable as id
+				return t.id
+			else
+				local d = assert(peek("destructuring"), "DestructuringId not in a destructurable assignement")
+				local vars = { id = tmp() }
+				for j=1, #t, 1 do
+					table.insert(vars, t[j])
+				end
+				table.insert(d, vars)
+				t.id = vars.id
+				return vars.id
+			end
+		end,
+		-- Index{ expr expr }
+		Index = (t)
+			if t[1].tag == "String" or t[1].tag == "Table" then
+				return "("..lua(t[1])..")["..lua(t[2]).."]"
+			else
+				return lua(t[1]).."["..lua(t[2]).."]"
+			end
+		end,
+		-- SafeIndex{ expr expr }
+		SafeIndex = (t)
+			if t[1].tag ~= "Id" then -- side effect possible, only evaluate each expr once (or already in a safe context)
+				local l = {} -- list of immediately chained safeindex, from deepest to nearest (to simply generated code)
+				while t.tag == "SafeIndex" or t.tag == "SafeCall" do
+					table.insert(l, 1, t)
+					t = t[1]
+				end
+				local r = "(function()"..indent().."local "..var"safe".." = "..lua(l[1][1])..newline() -- base expr
+				for _, e in ipairs(l) do
+					r ..= "if "..var"safe".." == nil then return nil end"..newline()
+					if e.tag == "SafeIndex" then
+						r ..= var"safe".." = "..var"safe".."["..lua(e[2]).."]"..newline()
+					else
+						r ..= var"safe".." = "..var"safe".."("..lua(e, "_lhs", 2)..")"..newline()
+					end
+				end
+				r ..= "return "..var"safe"..unindent().."end)()"
+				return r
+			else -- no side effects possible
+				return "("..lua(t[1]).." ~= nil and "..lua(t[1]).."["..lua(t[2]).."] or nil)"
+			end
+		end,
+
+		-- opid --
+		_opid = {
+			add = "+", sub = "-", mul = "*", div = "/",
+			idiv = "//", mod = "%", pow = "^", concat = "..",
+			band = "&", bor = "|", bxor = "~", shl = "<<", shr = ">>",
+			eq = "==", ne = "~=", lt = "<", gt = ">", le = "<=", ge = ">=",
+			["and"] = "and", ["or"] = "or", unm = "-", len = "#", bnot = "~", ["not"] = "not"
+		}
+	}, {
+		__index = (self, key)
+			error("don't know how to compile a "..tostring(key).." to "..targetName)
+		end
+	})
+
+	#placeholder("patch")
+
+	local code = lua(ast)..newline()
+	return requireStr..code
+end

compiler/luajit.can

@@ -3,13 +3,7 @@ targetName = "LuaJIT"
 UNPACK = (list, i, j)
 	return "unpack(" .. list .. (i and (", " .. i .. (j and (", " .. j) or "")) or "") .. ")"
 end
-APPEND = (t, toAppend)
-	return "do" .. indent() .. "local "..var("a")..", "..var("p").." = { " .. toAppend .. " }, #" .. t .. "+1" .. newline() .. "for i=1, #"..var("a").." do" .. indent() .. t .. "["..var("p").."] = "..var("a").."[i]" .. newline() .. ""..var("p").." = "..var("p").." + 1" .. unindent() .. "end" .. unindent() .. "end"
-end
 
-tags._opid.idiv = (left, right)
-	return "math.floor(" .. lua(left) .. " / " .. lua(right) .. ")"
-end
 tags._opid.band = (left, right)
 	addRequire("bit", "band", "band")
 	return var("band") .. "(" .. lua(left) .. ", " .. lua(right) .. ")"
@@ -39,6 +33,6 @@ end
 
 #local patch = output
 #output = ""
-#import("compiler.lua53", { patch = patch, loadPackage = false })
+#import("compiler.lua52", { preprocessorEnv = { patch = patch }, loadPackage = false })
 
-return lua53
+return lua52

rockspec/candran-1.0.0-1.rockspec

@@ -2,12 +2,12 @@ rockspec_format = "3.0"
 
 package = "candran"
 
-version = "0.12.0-1"
+version = "1.0.0-1"
 
 description = {
 	summary = "A simple Lua dialect and preprocessor.",
 	detailed = [[
-		Candran is a dialect of the Lua 5.3 programming language which compiles to Lua 5.3, LuaJIT and Lua 5.1 compatible code. It adds several useful syntax additions which aims to make Lua faster and easier to write, and a simple preprocessor.
+		Candran is a dialect of the Lua 5.4 programming language which compiles to Lua 5.4, Lua 5.3, Lua 5.2, LuaJIT and Lua 5.1 compatible code. It adds several useful syntax additions which aims to make Lua faster and easier to write, and a simple preprocessor.
 		Unlike Moonscript, Candran tries to stay close to the Lua syntax, and existing Lua code should be able to run on Candran unmodified.
 	]],
 	license = "MIT",
@@ -19,14 +19,15 @@ description = {
 
 source = {
 	url = "git://github.com/Reuh/candran",
-	tag = "v0.12.0"
+	tag = "v1.0.0"
 }
 
 dependencies = {
 	"lua >= 5.1",
 	"lpeglabel >= 1.5.0",
 	"linenoise >= 0.9",
-	"luacheck >= 0.23.0"
+	"luacheck >= 0.23.0",
+	"argparse >= 0.7.0"
 }
 
 build = {

rockspec/candran-scm-1.rockspec

@@ -25,7 +25,8 @@ dependencies = {
 	"lua >= 5.1",
 	"lpeglabel >= 1.5.0",
 	"linenoise >= 0.9",
-	"luacheck >= 0.23.0"
+	"luacheck >= 0.23.0",
+	"argparse >= 0.7.0"
 }
 
 build = {

test/test.lua

@@ -4,6 +4,37 @@ candran.default.mapLines = false
 
 local load = require("candran.util").load
 
+-- Text formatting
+local colors = {
+	black  = 30,
+	red    = 31,
+	green  = 32,
+	yellow = 33,
+	blue   = 34,
+	purple = 35,
+	cyan   = 36,
+	white  = 37,
+
+	bgBlack  = 40,
+	bgRed    = 41,
+	bgGreen  = 42,
+	bgYellow = 43,
+	bgBlue   = 44,
+	bgPurple = 45,
+	bgCyan   = 46,
+	bgWhite  = 47,
+
+	bold      = 1,
+	underline = 4
+}
+local function c(text, ...)
+	local codes = {}
+	for _, color in ipairs{...} do
+		table.insert(codes, colors[color])
+	end
+	return ("\027[%sm%s\027[0m"):format(table.concat(codes, ";"), text)
+end
+
 -- test helper
 local results = {} -- tests result
 local function test(name, candranCode, expectedResult, options)
@@ -18,7 +49,7 @@ local function test(name, candranCode, expectedResult, options)
 	local success, code = pcall(function() return assert(candran.make(candranCode, options)) end)
 	if not success then
 		self.result = "error"
-		self.message = "/!\\ error while making code:\n"..code
+		self.message = c("/!\\ error while making code:\n", "bold", "red")..c(code, "red")
 		return
 	end
 
@@ -28,7 +59,7 @@ local function test(name, candranCode, expectedResult, options)
 	local success, func = pcall(load, code, nil, env)
 	if not success then
 		self.result = "error"
-		self.message = "/!\\ error while loading code:\n"..func.."\ngenerated code:\n"..code
+		self.message = c("/!\\ error while loading code:\n"..func.."\ngenerated code:\n", "bold", "red")..c(code, "red")
 		return
 	end
 
@@ -36,14 +67,14 @@ local function test(name, candranCode, expectedResult, options)
 	local success, output = pcall(func)
 	if not success then
 		self.result = "error"
-		self.message = "/!\\ error while running code:\n"..output.."\ngenerated code:\n"..code
+		self.message = c("/!\\ error while running code:\n"..output.."\ngenerated code:\n", "bold", "red")..c(code, "red")
 		return
 	end
 
 	-- check result
 	if output ~= expectedResult then
 		self.result = "fail"
-		self.message = "/!\\ invalid result from the code; it returned "..tostring(output).." instead of "..tostring(expectedResult).."; generated code:\n"..code
+		self.message = c("/!\\ invalid result from the code; it returned "..tostring(output).." instead of "..tostring(expectedResult).."; generated code:\n", "bold", "purple")..c(code, "purple")
 		return
 	else
 		self.result = "success"
@@ -96,7 +127,7 @@ return a
 
 test("preprocessor placeholder function", [[
 #placeholder('foo')
-]], 5, { foo = "return 5" })
+]], 5, { preprocessorEnv = { foo = "return 5" } })
 
 test("preprocessor options", [[
 #if not foo == "sky" then
@@ -105,24 +136,80 @@ test("preprocessor options", [[
 return true
 ]], true, { foo = "sky" })
 
-test("preprocessor long comment", [[
---[[
+test("preprocessor long comment", "--[[\n"..[[
 #error("preprocessor should ignore long comments")
 ]].."]]"..[[
 return true
 ]], true)
 
 test("preprocessor long comment in long string", [[
-a=]].."[["..[[
---[[
+a=]].."[[--[[\n"..[[
 #error("preprocessor should ignore long strings")
 ]].."]]"..[[
 return a
-]], [[
---[[
+]], "--[[\n"..[[
 #error("preprocessor should ignore long strings")
 ]])
 
+test("preprocessor macro remove function", [[
+#define("log(...)", "")
+log("test")
+return true
+]], true)
+
+test("preprocessor macro replace function", [[
+#define("log(x)", "a = x")
+log("test")
+return a
+]], "test")
+
+test("preprocessor macro identifier replace function", [[
+#define("test(x)", "x = 42")
+test(hello)
+return hello
+]], 42)
+
+test("preprocessor macro replace function with vararg", [[
+#define("log(...)", "a, b, c = ...")
+log(1, 2, 3)
+assert(a == 1)
+assert(b == 2)
+assert(c == 3)
+return true
+]], true)
+
+test("preprocessor macro replace function with vararg and arg", [[
+#define("log(x, ...)", "a, b, c = x, ...")
+log(1, 2, 3)
+assert(a == 1)
+assert(b == 2)
+assert(c == 3)
+return true
+]], true)
+
+test("preprocessor macro replace variable", [[
+#define("a", "42")
+return a
+]], 42)
+
+test("preprocessor macro prevent recursive macro", [[
+#define("f(x)", "x")
+local x = 42
+x = f(x)
+return x
+]], 42)
+
+test("preprocessor macro replace variable with function", [[
+#define("a", function() return "42" end)
+return a
+]], 42)
+
+test("preprocessor macro replace function with function", [[
+#define("test(x)", function(x) return ("%s = 42"):format(x) end)
+test(hello)
+return hello
+]], 42)
+
 ----------------------
 -- SYNTAX ADDITIONS --
 ----------------------
@@ -585,6 +672,7 @@ test("table comprehension associative/self", [[
 	return a[1] and a[10]
 ]], true)
 test("table comprehension variable length", [[
+	local unpack = table.unpack or unpack
 	t1 = {"hey", "hop"}
 	t2 = {"foo", "bar"}
 	return table.concat([push unpack(t1); push unpack(t2)])
@@ -1024,7 +1112,8 @@ for name, t in pairs(results) do
 end
 
 -- print final results
-for name, count in pairs(resultCounter) do
-	print(count.." "..name.." (" .. math.floor((count / testCounter * 100)*100)/100 .. "%)")
+for _, name in ipairs{{"error", "red"}, {"fail", "purple"}, {"success", "green"}} do
+	local count = resultCounter[name[1]] or 0
+	print(c(count, "bold", name[2])..c(" "..name[1].." (" .. math.floor((count / testCounter * 100)*100)/100 .. "%)", name[2]))
 end
-print(testCounter.." total")
+print(c(testCounter.." total", "bold"))