Replace checkpoint system

The previous system needed to store of the scope and full AST to build a Resumable object, which means that if persisted, updating the resumable script will have no effect.
The new system instead uses an anchor token and does not require any information besides the anchor name.

parser/expression/secondary/infix/choice.lua

@@ -3,7 +3,7 @@ local infix = require("parser.expression.secondary.infix.infix")
 local operator_priority = require("common").operator_priority
 
 local ast = require("ast")
-local Call, Identifier, ArgumentTuple, ResumeParentFunction, ParameterTuple, Function = ast.Call, ast.Identifier, ast.ArgumentTuple, ast.ResumeParentFunction, ast.ParameterTuple, ast.Function
+local Call, Identifier, ArgumentTuple, ParameterTuple, Function = ast.Call, ast.Identifier, ast.ArgumentTuple, ast.ParameterTuple, ast.Function
 
 return infix {
 	operator = "|>",
@@ -11,7 +11,7 @@ return infix {
 	priority = operator_priority["_|>_"],
 
 	build_ast = function(self, left, right)
-		right = Function:new(ParameterTuple:new(), ResumeParentFunction:new(right))
+		right = Function:new(ParameterTuple:new(), right)
 		return Call:new(Identifier:new(self.identifier), ArgumentTuple:new(left, right))
 	end
 }

parser/expression/secondary/infix/resume.lua

@@ -0,0 +1,9 @@
+local infix_quote_right = require("parser.expression.secondary.infix.infix_quote_right")
+
+local operator_priority = require("common").operator_priority
+
+return infix_quote_right {
+	operator = "~>",
+	identifier = "_~>_",
+	priority = operator_priority["_~>_"]
+}

parser/expression/secondary/init.lua

@@ -8,10 +8,11 @@ local secondaries = {
 	-- binary infix operators
 	-- 1
 	r("infix.semicolon"),
-	r("infix.translate"),
 	-- 2
 	r("infix.tuple"),
 	r("infix.tag"),
+	r("infix.translate"),
+	r("infix.resume"),
 	-- 4
 	r("infix.while"),
 	r("infix.if"),