[internal] clean up format calls in interpolations, add format(val::is string) without quotes

anselme/ast/StringInterpolation.lua

@@ -36,10 +36,10 @@ local StringInterpolation = ast.abstract.Node {
 		local t = {}
 		for _, e in ipairs(self.list) do
 			local r = e:eval(state)
-			if String:is(r) then
+			if String:is(e) then -- raw string
-				r = r.string
+				r = e.string
-			else
+			else -- interpolation
-				r = r:format(state)
+				r = e:format_custom(state)
 			end
 			table.insert(t, r)
 		end

anselme/ast/TextInterpolation.lua

@@ -39,14 +39,14 @@ local TextInterpolation = ast.abstract.Node {
 		local tags = tag_manager:get(state)
 		for _, e in ipairs(self.list) do
 			local r = e:eval(state)
-			if String:is(r) then
+			if String:is(e) then -- raw string
 				t:insert(r, tags)
-			elseif Text:is(r) then
+			elseif Text:is(r) then -- interpolation
 				for _, v in ipairs(r.list) do
 					t:insert(v[1], v[2])
 				end
 			else
-				t:insert(String:new(r:format(state)), tags)
+				t:insert(String:new(r:format_custom(state)), tags)
 			end
 		end
 		return t

anselme/ast/Typed.lua

@@ -2,10 +2,6 @@ local ast = require("anselme.ast")
 
 local operator_priority = require("anselme.common").operator_priority
 
-local format_identifier
-
-local ArgumentTuple
-
 local Typed
 Typed = ast.abstract.Runtime {
 	type = "typed",
@@ -19,15 +15,6 @@ Typed = ast.abstract.Runtime {
 	end,
 
 	_format = function(self, state, prio, ...)
-		-- try custom format
-		if state and state.scope:defined(format_identifier) then
-			local custom_format = format_identifier:eval(state)
-			local args = ArgumentTuple:new(self)
-			local fn, d_args = custom_format:dispatch(state, args)
-			if fn then
-				return custom_format:call(state, d_args):format(state, prio, ...)
-			end
-		end
 		return ("type(%s, %s)"):format(self.expression:format(state, operator_priority["_,_"], ...), self.type_expression:format_right(state, operator_priority["_,_"], ...))
 	end,
 
@@ -37,8 +24,4 @@ Typed = ast.abstract.Runtime {
 	end
 }
 
-package.loaded[...] = Typed
-format_identifier = ast.Identifier:new("format")
-ArgumentTuple = ast.ArgumentTuple
-
 return Typed

anselme/ast/abstract/Node.lua

@@ -14,10 +14,10 @@ local unpack = table.unpack or unpack
 
 local uuid = require("anselme.common").uuid
 
-local Call, Identifier, Struct, Tuple, String, Pair
+local Call, Identifier, Struct, Tuple, String, Pair, ArgumentTuple
 local resume_manager
 
-local custom_call_identifier
+local custom_call_identifier, custom_format_identifier
 
 local context_max_length = 50
 local function cutoff_text(str)
@@ -372,6 +372,18 @@ Node = class {
 	_format_priority_cache = nil, -- cached priority
 	from_symbol = nil, -- last symbol this node was retrived from
 
+	-- return a human-readable, string representation of the node
+	-- this works by calling the `format(node)` anselme method (if the method returns a non-string value, it is converted to a string using :format)
+	format_custom = function(self, state)
+		local custom_format = custom_format_identifier:eval(state)
+		local r = custom_format:call(state, ArgumentTuple:new(self))
+		if String:is(r) then
+			return r.string
+		else
+			return r:format(state)
+		end
+	end,
+
 	-- return Lua value
 	-- this should probably be only called on a Node that is already evaluated
 	-- redefine if you want, probably only for nodes that are already evaluated
@@ -430,8 +442,9 @@ Node = class {
 	-- Thus, any require here that may require other Nodes shall be done here. This method is called in anselme.lua after everything else is required.
 	_i_hate_cycles = function(self)
 		local ast = require("anselme.ast")
-		Call, Identifier, Struct, Tuple, String, Pair = ast.Call, ast.Identifier, ast.Struct, ast.Tuple, ast.String, ast.Pair
+		Call, Identifier, Struct, Tuple, String, Pair, ArgumentTuple = ast.Call, ast.Identifier, ast.Struct, ast.Tuple, ast.String, ast.Pair, ast.ArgumentTuple
 		custom_call_identifier = Identifier:new("_!")
+		custom_format_identifier = Identifier:new("format")
 
 		resume_manager = require("anselme.state.resume_manager")
 	end,

anselme/stdlib/base.lua

@@ -5,12 +5,18 @@ return {
 	{
 		"print", "(a)",
 		function(state, a)
-			print(a:format(state))
+			print(a:format_custom(state))
 			return Nil:new()
 		end
 	},
 	{
 		"hash", "(a)",
+		"format", "(val)",
+		function(state, val)
+			return String:new(val:format(state))
+		end
+	},
+	{
 		function(state, a)
 			return String:new(a:hash())
 		end

anselme/stdlib/string.lua

@@ -9,5 +9,11 @@ return {
 		function(state, s)
 			return Number:new(utf8.len(s.string))
 		end
+	},
+	{
+		"format", "(val::is string)",
+		function(state, val)
+			return val
+		end
 	}
 }

doc/language.md

@@ -485,7 +485,7 @@ Strings literal starts with a `"` and end with a `"`. Specials characters, inclu
 * `\n` is replaced with a newline
 * `\t` is replaced with a tab character
 
-Non-escaped `{` in the string start an interpolated expression; any expression can then follow, but a closing `}` is expected after it. When the string literal is evaluated, each interpolated expression will be evaluated, the returned value will be formatted to a string and appear in the string where the `{` expression `}` appeared in the literal.
+Non-escaped `{` in the string start an interpolated expression; any expression can then follow, but a closing `}` is expected after it. When the string literal is evaluated, each interpolated expression will be evaluated, the returned value will be converted to a string using `format` and appear in the string where the `{` expression `}` appeared in the literal.
 
 Strings can contain newlines.
 
@@ -680,7 +680,7 @@ var!type // returns "$"
 var!value // returns 10
 ```
 
-When trying to convert the custom type to a string, for example in a string interpolation, the `format(custom type)` function call will be tried. If the function can be called, its return value will be used as the string representation of the value.
+When trying to convert the custom type to a string, for example in a string interpolation, the `format(custom type)` function will be called. How custom types appear in strings can therefore be changed by overloading the `format` function.
 
 ```
 :var = type(10, "$")

test/results/custom text formatting.ans

@@ -1,6 +1,6 @@
 --# run #--
 --- text ---
-| {}"" {}"\"Name: Darmanin\nAge: 38\"" {}"" |
+| {}"" {}"Name: Darmanin\nAge: 38" {}"" |
 --- return ---
 ()
 --# saved #--