From e71096cab76e956698c038873bff52ce0c569c3d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89tienne=20Reuh=20Fildadut?= <fildadut@reuh.eu>
Date: Tue, 2 Jan 2024 00:34:30 +0100
Subject: [PATCH] Remove ~, ~?, and @ operators and replace with function calls

---
 anselme/common/init.lua                       |  5 +--
 anselme/parser/expression/primary/init.lua    |  6 ---
 .../parser/expression/primary/prefix/else.lua |  8 ----
 .../expression/primary/prefix/return.lua      | 15 --------
 .../parser/expression/secondary/infix/if.lua  |  9 -----
 .../infix/implicit_multiplication.lua         |  2 +-
 .../expression/secondary/infix/while.lua      |  9 -----
 anselme/parser/expression/secondary/init.lua  | 19 ----------
 .../expression/secondary/suffix/call.lua      |  6 ++-
 anselme/state/State.lua                       |  6 ++-
 anselme/stdlib/checkpoint.lua                 |  2 +-
 anselme/stdlib/closure.lua                    |  9 ++++-
 anselme/stdlib/conditionals.lua               | 38 +++++++++++++++----
 anselme/stdlib/script_script.lua              | 30 +++++++--------
 14 files changed, 65 insertions(+), 99 deletions(-)
 delete mode 100644 anselme/parser/expression/primary/prefix/else.lua
 delete mode 100644 anselme/parser/expression/primary/prefix/return.lua
 delete mode 100644 anselme/parser/expression/secondary/infix/if.lua
 delete mode 100644 anselme/parser/expression/secondary/infix/while.lua

diff --git a/anselme/common/init.lua b/anselme/common/init.lua
index bdad1ce..acf07a8 100644
--- a/anselme/common/init.lua
+++ b/anselme/common/init.lua
@@ -31,7 +31,6 @@ local common = {
 	regular_operators = {
 		prefixes = {
 			{ ">", 3.1 }, -- just above _=_
-			{ "~", 3.5 }, -- just below _~_ so else-if (~ condition ~ expression) parses as (~ (condition ~ expression))
 			{ "!", 11 },
 			{ "-", 11 },
 			{ "*", 11 },
@@ -44,7 +43,6 @@ local common = {
 		infixes = {
 			{ ";", 1 },
 			{ "#", 2 }, { "->", 2 },
-			{ "~", 4 }, { "~?", 4 },
 			{ "|>", 5 }, { "&", 5 }, { "|", 5 },
 			{ "==", 7 }, { "!=", 7 }, { ">=", 7 }, { "<=", 7 }, { "<", 7 }, { ">", 7 },
 			{ "+", 8 }, { "-", 8 },
@@ -58,8 +56,7 @@ local common = {
 	-- list of all operators and their priority
 	operator_priority = {
 		[";_"] = 1,
-		["$_"] = 1,
-		["@_"] = 1,
+		["$_"] = 2,
 		["_,_"] = 2,
 		["_=_"] = 3,
 		["_!_"] = 12,
diff --git a/anselme/parser/expression/primary/init.lua b/anselme/parser/expression/primary/init.lua
index 82ce6d8..e7c717d 100644
--- a/anselme/parser/expression/primary/init.lua
+++ b/anselme/parser/expression/primary/init.lua
@@ -18,15 +18,9 @@ local primaries = {
 	r("struct"),
 
 	-- prefixes
-	-- 1
 	r("prefix.semicolon"),
 	r("prefix.function"),
-	r("prefix.return"),
-	-- 3.1
 	r("prefix.wrap"),
-	-- 3.5
-	r("prefix.else"),
-	-- 11
 	r("prefix.negation"),
 	r("prefix.not"),
 	r("prefix.mutable"),
diff --git a/anselme/parser/expression/primary/prefix/else.lua b/anselme/parser/expression/primary/prefix/else.lua
deleted file mode 100644
index 6da0d46..0000000
--- a/anselme/parser/expression/primary/prefix/else.lua
+++ /dev/null
@@ -1,8 +0,0 @@
-local prefix_quote_right = require("anselme.parser.expression.primary.prefix.prefix_quote_right")
-local operator_priority = require("anselme.common").operator_priority
-
-return prefix_quote_right {
-	operator = "~",
-	identifier = "~_",
-	priority = operator_priority["~_"]
-}
diff --git a/anselme/parser/expression/primary/prefix/return.lua b/anselme/parser/expression/primary/prefix/return.lua
deleted file mode 100644
index c3b8764..0000000
--- a/anselme/parser/expression/primary/prefix/return.lua
+++ /dev/null
@@ -1,15 +0,0 @@
-local prefix_maybe_nil_right = require("anselme.parser.expression.primary.prefix.prefix_maybe_nil_right")
-
-local ast = require("anselme.ast")
-local Return = ast.Return
-
-local operator_priority = require("anselme.common").operator_priority
-
-return prefix_maybe_nil_right {
-	operator = "@",
-	priority = operator_priority["@_"],
-
-	build_ast = function(self, right)
-		return Return:new(right)
-	end
-}
diff --git a/anselme/parser/expression/secondary/infix/if.lua b/anselme/parser/expression/secondary/infix/if.lua
deleted file mode 100644
index fc7c7ab..0000000
--- a/anselme/parser/expression/secondary/infix/if.lua
+++ /dev/null
@@ -1,9 +0,0 @@
-local infix_quote_right = require("anselme.parser.expression.secondary.infix.infix_quote_right")
-
-local operator_priority = require("anselme.common").operator_priority
-
-return infix_quote_right {
-	operator = "~",
-	identifier = "_~_",
-	priority = operator_priority["_~_"]
-}
diff --git a/anselme/parser/expression/secondary/infix/implicit_multiplication.lua b/anselme/parser/expression/secondary/infix/implicit_multiplication.lua
index ad5a9c7..4757e06 100644
--- a/anselme/parser/expression/secondary/infix/implicit_multiplication.lua
+++ b/anselme/parser/expression/secondary/infix/implicit_multiplication.lua
@@ -9,7 +9,7 @@ local Call, Identifier, ArgumentTuple = ast.Call, ast.Identifier, ast.ArgumentTu
 return infix {
 	operator = "*",
 	identifier = "_*_",
-	priority = operator_priority["_*_"]+.5, -- just above / so 1/2x gives 1/(2x)
+	priority = operator_priority["_*_"]+.1, -- just above / so 1/2x gives 1/(2x)
 
 	match = function(self, str, current_priority, primary)
 		return self.priority > current_priority and identifier:match(str)
diff --git a/anselme/parser/expression/secondary/infix/while.lua b/anselme/parser/expression/secondary/infix/while.lua
deleted file mode 100644
index 464dbb2..0000000
--- a/anselme/parser/expression/secondary/infix/while.lua
+++ /dev/null
@@ -1,9 +0,0 @@
-local infix_quote_both = require("anselme.parser.expression.secondary.infix.infix_quote_both")
-
-local operator_priority = require("anselme.common").operator_priority
-
-return infix_quote_both {
-	operator = "~?",
-	identifier = "_~?_",
-	priority = operator_priority["_~?_"]
-}
diff --git a/anselme/parser/expression/secondary/init.lua b/anselme/parser/expression/secondary/init.lua
index 08b50a3..cc4d412 100644
--- a/anselme/parser/expression/secondary/init.lua
+++ b/anselme/parser/expression/secondary/init.lua
@@ -6,58 +6,39 @@ end
 
 local secondaries = {
 	-- binary infix operators
-	-- 1
 	r("infix.semicolon"),
-	-- 2
 	r("infix.tuple"),
 	r("infix.tag"),
 	r("infix.translate"),
-	-- 4
-	r("infix.while"),
-	r("infix.if"),
-	-- 6
 	r("infix.choice"),
 	r("infix.and"),
 	r("infix.or"),
-	-- 7
 	r("infix.equal"),
 	r("infix.different"),
 	r("infix.greater_equal"),
 	r("infix.lower_equal"),
 	r("infix.greater"),
 	r("infix.lower"),
-	-- 8
 	r("infix.addition"),
 	r("infix.substraction"),
-	-- 9
 	r("infix.multiplication"),
 	r("infix.integer_division"),
 	r("infix.division"),
 	r("infix.modulo"),
-	-- 9.5
 	r("infix.implicit_multiplication"),
-	-- 10
 	r("infix.exponent"),
-	-- 11
 	r("infix.type_check"),
-	-- 12
 	r("infix.call"),
-	-- 14
 	r("infix.index_identifier"),
 	r("infix.index"),
-	-- 3
 	r("infix.assignment"), -- deported after equal
 	r("infix.assignment_call"),
 	r("infix.definition"),
-	-- 5
 	r("infix.pair"), -- deported after type_check
 
 	-- unary suffix operators
-	-- 1
 	r("suffix.semicolon"),
-	-- 12
 	r("suffix.exclamation_call"),
-	-- 13
 	r("suffix.call"),
 }
 
diff --git a/anselme/parser/expression/secondary/suffix/call.lua b/anselme/parser/expression/secondary/suffix/call.lua
index 7f634c7..100015c 100644
--- a/anselme/parser/expression/secondary/suffix/call.lua
+++ b/anselme/parser/expression/secondary/suffix/call.lua
@@ -22,7 +22,11 @@ return secondary {
 		local exp, rem = parenthesis:parse(source, str, limit_pattern)
 
 		if Nil:is(exp) then
-			exp = Tuple:new()
+			if str:match("^%(%s*%(%s*%)%s*%)") then -- special case: single nil argument
+				exp = Tuple:new(Nil:new())
+			else -- no arguments
+				exp = Tuple:new()
+			end
 		elseif not Tuple:is(exp) or exp.explicit then -- single argument
 			exp = Tuple:new(exp)
 		end
diff --git a/anselme/state/State.lua b/anselme/state/State.lua
index 9fa3f98..6d3a169 100644
--- a/anselme/state/State.lua
+++ b/anselme/state/State.lua
@@ -12,7 +12,7 @@ local parser = require("anselme.parser")
 local binser = require("anselme.lib.binser")
 local assert0 = require("anselme.common").assert0
 local anselme
-local Identifier
+local Identifier, Return
 
 local State
 State = class {
@@ -158,6 +158,7 @@ State = class {
 		self._coroutine = coroutine.create(function()
 			local r = assert0(self:eval_local(code, source))
 			event_manager:final_flush(self)
+			if Return:is(r) then r = r.expression end
 			return "return", r
 		end)
 	end,
@@ -194,6 +195,7 @@ State = class {
 				local r = assert0(self:eval_local(code, source))
 				event_manager:final_flush(self)
 				self.scope:reset() -- scope stack is probably messed up after the switch
+				if Return:is(r) then r = r.expression end
 				return "return", r
 			end)
 		else
@@ -239,6 +241,6 @@ State = class {
 package.loaded[...] = State
 anselme = require("anselme")
 local ast = require("anselme.ast")
-Identifier = ast.Identifier
+Identifier, Return = ast.Identifier, ast.Return
 
 return State
diff --git a/anselme/stdlib/checkpoint.lua b/anselme/stdlib/checkpoint.lua
index 2abad0f..19e2912 100644
--- a/anselme/stdlib/checkpoint.lua
+++ b/anselme/stdlib/checkpoint.lua
@@ -45,5 +45,5 @@ return {
 			state:merge()
 			return Nil:new()
 		end
-	}
+	},
 }
diff --git a/anselme/stdlib/closure.lua b/anselme/stdlib/closure.lua
index 702e26c..f27747f 100644
--- a/anselme/stdlib/closure.lua
+++ b/anselme/stdlib/closure.lua
@@ -65,7 +65,14 @@ return {
 				return get
 			end
 		end
-	}
+	},
+	{
+		"return", "(value=())",
+		function(state, val)
+			if Return:is(val) then val = val.expression end
+			return Return:new(val)
+		end
+	},
 	{
 		"attached block", "(level::number=1)",
 		function(state, level)
diff --git a/anselme/stdlib/conditionals.lua b/anselme/stdlib/conditionals.lua
index 459fc6f..07b8308 100644
--- a/anselme/stdlib/conditionals.lua
+++ b/anselme/stdlib/conditionals.lua
@@ -1,8 +1,6 @@
 local ast = require("anselme.ast")
 local ArgumentTuple, Nil, Boolean, Identifier, Return = ast.ArgumentTuple, ast.Nil, ast.Boolean, ast.Identifier, ast.Return
 
-local resume_manager = require("anselme.state.resume_manager")
-
 local if_identifier = Identifier:new("_if_status")
 local if_symbol = if_identifier:to_symbol()
 
@@ -20,9 +18,9 @@ end
 
 return {
 	{
-		"_~_", "(condition, expression)", function(state, condition, expression)
+		"if", "(condition, expression=attached block keep return!)", function(state, condition, expression)
 			ensure_if_variable(state)
-			if condition:truthy() or resume_manager:resuming(state) then--expression:contains_current_resume_target(state) then TODO fix
+			if condition:truthy() or expression:contains_current_resume_target(state) then
 				set_if_variable(state, true)
 				return expression:call(state, ArgumentTuple:new())
 			else
@@ -32,10 +30,35 @@ return {
 		end
 	},
 	{
-		"~_", "(expression)",
+		"if", "(condition, true, false)", function(state, condition, if_true, if_false)
+			ensure_if_variable(state)
+			if condition:truthy() or if_true:contains_current_resume_target(state) then
+				set_if_variable(state, true)
+				return if_true:call(state, ArgumentTuple:new())
+			else
+				set_if_variable(state, false)
+				return if_false:call(state, ArgumentTuple:new())
+			end
+		end
+	},
+	{
+		"else if", "(condition, expression=attached block keep return!)",
+		function(state, condition, expression)
+			ensure_if_variable(state)
+			if (not last_if_success(state) and condition:truthy()) or expression:contains_current_resume_target(state) then
+				set_if_variable(state, true)
+				return expression:call(state, ArgumentTuple:new())
+			else
+				set_if_variable(state, false)
+				return Nil:new()
+			end
+		end
+	},
+	{
+		"else", "(expression=attached block keep return!)",
 		function(state, expression)
 			ensure_if_variable(state)
-			if not last_if_success(state) or resume_manager:resuming(state) then--expression:contains_current_resume_target(state) then TODO fix
+			if not last_if_success(state) or expression:contains_current_resume_target(state) then
 				set_if_variable(state, true)
 				return expression:call(state, ArgumentTuple:new())
 			else
@@ -43,9 +66,8 @@ return {
 			end
 		end
 	},
-
 	{
-		"_~?_", "(condition, expression)",
+		"while", "(condition, expression=attached block keep return!)",
 		function(state, condition, expression)
 			ensure_if_variable(state)
 			local cond = condition:call(state, ArgumentTuple:new())
diff --git a/anselme/stdlib/script_script.lua b/anselme/stdlib/script_script.lua
index e4167b8..4078a07 100644
--- a/anselme/stdlib/script_script.lua
+++ b/anselme/stdlib/script_script.lua
@@ -1,5 +1,5 @@
 return [[
-:@script = $(name, fn)
+:@script = $(name, fn=attached block!)
 	fn.:&current checkpoint => "{name}.checkpoint"!persist(false)
 	fn.:&reached => "{name}.reached"!persist(*{})
 	fn.:&run => "{name}.run"!persist(0)
@@ -10,22 +10,22 @@ return [[
 		fn.reached(anchor) = (fn.reached(anchor) | 0) + 1
 	fn.:checkpoint = $(anchor::anchor)
 		fn.current checkpoint = anchor
-		resumed from != anchor ~
+		if(resumed from != anchor)
 			fn.reached(anchor) = (fn.reached(anchor) | 0) + 1
 			merge branch!
 	fn.:checkpoint = $(anchor::anchor, on resume::function)
 		fn.current checkpoint = anchor
-		resumed from == anchor | resuming(1) ~
+		if(resumed from == anchor | resuming(2))
 			on resume!
-		~
+		else!
 			fn.reached(anchor) = (fn.reached(anchor) | 0) + 1
 			merge branch!
 
 	:f = $
-		fn.current checkpoint ~
+		if(fn.current checkpoint)
 			resumed from = fn.current checkpoint
 			fn!resume(fn.current checkpoint)
-		~
+		else!
 			resumed from = ()
 			fn!
 		fn.run += 1
@@ -38,7 +38,7 @@ return [[
 	s!value!
 
 :@$_._(s::is script, k::string)
-	@(s!value).fn.(k)
+	(s!value).fn.(k)
 :@$_._(s::is script, k::string) = val
 	(s!value).fn.(k) = val
 :@$_._(s::is script, k::symbol) = val
@@ -46,25 +46,25 @@ return [[
 
 :@$from(s::is script, a::anchor)
 	s.current checkpoint = a
-	@s!
+	return(s!)
 :@$from(s::is script)
 	s.current checkpoint = ()
-	@s!
+	return(s!)
 
 /*Additionnal helpers*/
 :@$ cycle(l::tuple)
 	:i = 2
-	i <= l!len ~?
-		l(i).run < l(1).run ~
-			@l(i)!
+	while($i <= l!len)
+		if(l(i).run < l(1).run)
+			return(l(i)!)
 		i += 1
 	l(1)!
 
 :@$ next(l::tuple)
 	:i = 1
-	i <= l!len ~?
-		l(i).run == 0 ~
-			@l(i)!
+	while($i <= l!len)
+		if(l(i).run == 0)
+			return(l(i)!)
 		i += 1
 	l(i-1)!