Rename REAMDE to README.md

[nit.git] / src / literal.nit

diff --git a/src/literal.nit b/src/literal.nit
index 23dcacd..d6cb84e 100644 (file)
--- a/src/literal.nit
+++ b/src/literal.nit
@@ -56,6 +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
@@ -91,7 +123,7 @@ redef class ACharExpr
        do
                var txt = self.n_char.text.unescape_nit
                if txt.length != 3 then
-                       v.toolcontext.error(self.hot_location, "Invalid character literal {txt}")
+                       v.toolcontext.error(self.hot_location, "Syntax Error: invalid character literal `{txt}`.")
                        return
                end
                self.value = txt.chars[1]