[stdlib] Add keep return(function)

anselme/ast/Function.lua

@@ -27,6 +27,16 @@ Function = ast.abstract.Overloadable {
 		return Function:new(parameters, ReturnBoundary:new(expression))
 	end,
 
+	-- returns the same function, without the return boundary
+	-- this does not create a new function scope
+	without_return_boundary = function(self)
+		if ReturnBoundary:is(self.expression) then
+			return Function:new(self.parameters, self.expression.expression, self.scope, self.upvalues)
+		else
+			return self
+		end
+	end,
+
 	_format = function(self, ...)
 		if self.parameters.assignment then
 			return "$"..self.parameters:format_short(...).."; "..self.expression:format_right(...)

anselme/stdlib/function.lua

@@ -26,6 +26,13 @@ return {
 		end
 	},
 
+	{
+		"keep return", "(f::is function)",
+		function(state, f)
+			return f:without_return_boundary()
+		end
+	},
+
 	{
 		"_._", "(c::is function, s::is string)",
 		function(state, c, s)

anselme/stdlib/language/frFR.lua

@@ -12,6 +12,7 @@ return [[
 
 :@défini = stdlib.defined
 :@surcharge = stdlib.overload
+:@préserver retour = stdlib.keep return
 
 :@si = stdlib.if
 :@sinon = stdlib.else