From c5be1088c5bcb58592e3de23347cdb31be1ee644 Mon Sep 17 00:00:00 2001
From: Reuh <fildadut@reuh.eu>
Date: Fri, 26 Dec 2025 15:12:33 +0100
Subject: [PATCH] feat: add named varargs from Lua 5.5

---
 candran/can-parser/parser.lua    |  6 ++--
 candran/can-parser/validator.lua |  4 +--
 compiler/lua55.can               | 48 ++++++++++++++++++--------------
 3 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/candran/can-parser/parser.lua b/candran/can-parser/parser.lua
index 615e006..baf92f7 100644
--- a/candran/can-parser/parser.lua
+++ b/candran/can-parser/parser.lua
@@ -34,7 +34,7 @@ expr:
   | `Boolean{ <boolean> }
   | `Number{ <string> }  -- we don't use convert to number to avoid losing precision when tostring()-ing it later
   | `String{ <string> }
-  | `Function{ { ( `ParPair{ Id expr } | `Id{ <string> } )* `Dots? } block }
+  | `Function{ { ( `ParPair{ Id expr } | `Id{ <string> } )* `ParDots? } block }
   | `Table{ ( `Pair{ expr expr } | expr )* }
   | `Op{ opid expr expr? }
   | `Paren{ expr }       -- significant to cut multiple values returns
@@ -573,8 +573,8 @@ local G = { V"Lua",
               * (sym(":") * expect(V"StrId", "NameFunc2"))^-1 / markMethod;
   FuncBody    = tagC("Function", V"FuncParams" * expectBlockWithEnd("EndFunc"));
   FuncParams  = expect(sym("("), "OParenPList") * V"ParList" * expect(sym(")"), "CParenPList");
-  ParList     = V"NamedParList" * (sym(",") * expect(tagC("Dots", sym("...")), "ParList"))^-1 / addDots
-              + Ct(tagC("Dots", sym("...")))
+  ParList     = V"NamedParList" * (sym(",") * expect(tagC("ParDots", sym("...") * V"Id"^-1), "ParList"))^-1 / addDots
+              + Ct(tagC("ParDots", sym("...") * V"Id"^-1))
               + Ct(Cc()); -- Cc({}) generates a bug since the {} would be shared across parses
 
   ShortFuncDef    = tagC("Function", V"ShortFuncParams" * maybeBlockWithEnd()) / fixShortFunc;
diff --git a/candran/can-parser/validator.lua b/candran/can-parser/validator.lua
index 6e7bd8d..c722003 100644
--- a/candran/can-parser/validator.lua
+++ b/candran/can-parser/validator.lua
@@ -71,7 +71,7 @@ local traverse_block, traverse_explist, traverse_varlist, traverse_parlist
 function traverse_parlist (env, parlist)
   local len = #parlist
   local is_vararg = false
-  if len > 0 and parlist[len].tag == "Dots" then
+  if len > 0 and parlist[len].tag == "ParDots" then
     is_vararg = true
   end
   set_vararg(env, is_vararg)
@@ -348,7 +348,7 @@ function traverse_exp (env, exp)
     return true
   elseif tag == "Dots" then
     return traverse_vararg(env, exp)
-  elseif tag == "Function" then -- `Function{ { `Id{ <string> }* `Dots? } block }
+  elseif tag == "Function" then -- `Function{ { `Id{ <string> }* `ParDots? } block }
     return traverse_function(env, exp)
   elseif tag == "Table" then -- `Table{ ( `Pair{ expr expr } | expr )* }
     return traverse_table(env, exp)
diff --git a/compiler/lua55.can b/compiler/lua55.can
index 08c87c8..add25c5 100644
--- a/compiler/lua55.can
+++ b/compiler/lua55.can
@@ -587,33 +587,35 @@ return function(code, ast, options, macros={functions={}, variables={}})
 		String = (t)
 			return "%q":format(t[1])
 		end,
-		-- Function{ { ( `ParPair{ Id expr } | `Id{ <string> } )* `Dots? } block }
+		-- Function{ { ( `ParPair{ Id expr } | `Id{ <string> } )* `ParDots? } block }
+		_functionParameter = {
+			ParPair = (t, decl)
+				local id = lua(t[1])
+				indentLevel += 1
+				table.insert(decl, "if "..id.." == nil then "..id.." = "..lua(t[2]).." end")
+				indentLevel -= 1
+				return id
+			end,
+			ParDots = (t, decl)
+				if #t == 1 then
+					return "..." .. lua(t[1])
+				else
+					return "..."
+				end
+			end,
+		},
 		_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
+			local pars = {}
+			for i=1, #t[1], 1 do
+				if tags._functionParameter[t[1][i].tag] then
+					table.insert(pars, tags._functionParameter[t[1][i].tag](t[1][i], decl))
 				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
+					table.insert(pars, lua(t[1][i]))
 				end
 			end
-			r ..= ")"..indent()
+			r ..= table.concat(pars, ", ")..")"..indent()
 			for _, d in ipairs(decl) do
 				r ..= d..newline()
 			end
@@ -851,6 +853,10 @@ return function(code, ast, options, macros={functions={}, variables={}})
 		AttributeNameList = (t)
 			return lua(t, "_lhs")
 		end,
+		-- NameList{ {Id+} }
+		NameList = (t)
+			return lua(t, "_lhs")
+		end,
 		-- AttributeId{ <string> <string>? }
 		AttributeId = (t)
 			if t[2] then