[language] convert identifier to string when used as the name in a pair

anselme/ast/Identifier.lua

@@ -4,6 +4,7 @@ local Symbol, String
 local Identifier
 Identifier = ast.abstract.Node {
 	type = "identifier",
+	parenthesied = false, -- true if identifier was wrapped in parentheses
 
 	name = nil,
 

anselme/parser/expression/primary/parenthesis.lua

@@ -3,7 +3,7 @@
 local primary = require("anselme.parser.expression.primary.primary")
 
 local ast = require("anselme.ast")
-local Nil = ast.Nil
+local Nil, Identifier = ast.Nil, ast.Identifier
 
 local expression_to_ast = require("anselme.parser.expression.to_ast")
 
@@ -27,6 +27,9 @@ return primary {
 			if not s then error("invalid expression inside parentheses: "..exp, 0) end
 			rem = source:consume_leading_whitespace(opts, rem)
 			if not rem:match("^%)") then error(("unexpected %q at end of parenthesis"):format(rem:match("^[^\n]*")), 0) end
+			if Identifier:is(exp) then
+				exp.parenthesied = true
+			end
 		end
 		rem = source:consume(rem:match("^(%))(.*)$"))
 

anselme/parser/expression/secondary/infix/pair.lua

@@ -2,8 +2,18 @@ local infix = require("anselme.parser.expression.secondary.infix.infix")
 
 local operator_priority = require("anselme.common").operator_priority
 
+local ast = require("anselme.ast")
+local Call, Identifier, ArgumentTuple = ast.Call, ast.Identifier, ast.ArgumentTuple
+
 return infix {
 	operator = ":",
 	identifier = "_:_",
-	priority = operator_priority["_:_"]
+	priority = operator_priority["_:_"],
+
+	build_ast = function(self, left, right)
+		if Identifier:is(left) and not left.parenthesied then
+			left = left:to_string()
+		end
+		return Call:new(Identifier:new(self.identifier), ArgumentTuple:new(left, right))
+	end
 }

doc/language.md

@@ -415,10 +415,15 @@ The `break` and `continue` functions from the standard library also return retur
 
 Pairs associate two arbitrary values.
 
-Pairs are built using the `_:_` identifier, with the left argument giving the name and the right the value of the pair.
+Pairs are built using the `_:_` identifier, with the left argument giving the name and the right the value of the pair. If the left argument is an identifier, it will be converted to a string for convenience.
 
 ```
-"name":"value"
+"name":"value" -- is the same as
+name:"value"
+
+-- if you need to use the value associated with the `name` variable instead, the identifier can be wrapped in parentheses
+:name = "key"
+(name):"value"
 ```
 
 ### Tuple

test/results/pair operator.ans

@@ -1,7 +1,7 @@
 --# run #--
 --- text ---
-| {}"" {}"[\"test\":1, 3:\"p\", \"test\":\"foo\", \"ho\":\"ah\", \"test\":\"test\"]" {}"" |
 | {}"" {}"[\"name\":1, 3:\"p\", \"test\":\"foo\", \"ho\":\"ah\", \"name\":\"test\"]" {}"" |
+| {}"" {}"[\"name\":1, 3:\"p\", \"name\":\"foo\", \"ho\":\"ah\", \"name\":\"test\"]" {}"" |
 --- return ---
 ()
 --# saved #--

test/tests/function call struct.ans

@@ -1,4 +1,4 @@
 :f = $(l)
 	|{l}
 
-f{4:3,true:6,"l":8}
+f{4:3,(true):6,"l":8}