Rename REAMDE to README.md

[nit.git] / src / literal.nit

diff --git a/src/literal.nit b/src/literal.nit
index 668f72a..d6cb84e 100644 (file)
--- a/src/literal.nit
+++ b/src/literal.nit
@@ -17,11 +17,10 @@
 # Parsing of literal values in the abstract syntax tree.
 module literal
 
-import parser
-import toolcontext
 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
 
@@ -46,11 +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)
@@ -62,15 +56,57 @@ 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
+end
+
+redef class ADecIntExpr
        redef fun accept_literal(v)
        do
                self.value = self.n_number.text.to_i
        end
 end
 
+redef class AHexIntExpr
+       redef fun accept_literal(v)
+       do
+               self.value = self.n_hex_number.text.substring_from(2).to_hex
+       end
+end
+
 redef class AFloatExpr
        # The value of the literal float once computed.
        var value: nullable Float
@@ -87,10 +123,10 @@ 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[1]
+               self.value = txt.chars[1]
        end
 end
 
@@ -100,8 +136,13 @@ redef class AStringFormExpr
        redef fun accept_literal(v)
        do
                var txt = self.n_string.text
-               var skip = 1
-               if txt[0] == txt[1] and txt.length >= 6 then skip = 3
-               self.value = txt.substring(skip, txt.length-(2*skip)).unescape_nit
+               var behead = 1
+               var betail = 1
+               if txt.chars[0] == txt.chars[1] and txt.length >= 6 then
+                       behead = 3
+                       betail = 3
+                       if txt.chars[0] == '"' and txt.chars[3] == '\n' then behead = 4 # ignore first \n in """
+               end
+               self.value = txt.substring(behead, txt.length - behead - betail).unescape_nit
        end
 end