X-Git-Url: http://nitlanguage.org

diff --git a/src/literal.nit b/src/literal.nit
index ef4851b..bc361ab 100644
--- a/src/literal.nit
+++ b/src/literal.nit
@@ -20,6 +20,7 @@ module literal
 import phase
 
 redef class ToolContext
+	# Parses literal values in the whole AST and produces errors if needed
 	var literal_phase: Phase = new LiteralPhase(self, null)
 end
 
@@ -44,11 +45,6 @@ private class LiteralVisitor
 
 	var toolcontext: ToolContext
 
-	init(toolcontext: ToolContext)
-	do
-		self.toolcontext = toolcontext
-	end
-
 	redef fun visit(n)
 	do
 		n.accept_literal(self)
@@ -60,6 +56,38 @@ redef class ANode
 	private fun accept_literal(v: LiteralVisitor) do end
 end
 
+redef class AExpr
+	# Get `self` as a `String`.
+	# Return null if not a string.
+	fun as_string: nullable String
+	do
+		if not self isa AStringFormExpr then return null
+		return self.value.as(not null)
+	end
+
+	# Get `self` as an `Int`.
+	# Return null if not an integer.
+	fun as_int: nullable Int
+	do
+		if not self isa AIntExpr then return null
+		return self.value.as(not null)
+	end
+
+	# Get `self` as a single identifier.
+	# Return null if not a single identifier.
+	fun as_id: nullable String
+	do
+		if self isa AMethidExpr then
+			return self.collect_text
+		end
+		if not self isa ACallExpr then return null
+		if not self.n_expr isa AImplicitSelfExpr then return null
+		if not self.n_args.n_exprs.is_empty then return null
+		return self.n_id.text
+	end
+end
+
+
 redef class AIntExpr
 	# The value of the literal int once computed.
 	var value: nullable Int