src/literal.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2012 Jean Privat <jean@pryen.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Parsing of literal values in the abstract syntax tree.
  18 module literal
  19
  20 import parser
  21 import toolcontext
  22 import phase
  23
  24 redef class ToolContext
  25         var literal_phase: Phase = new LiteralPhase(self, null)
  26 end
  27
  28 private class LiteralPhase
  29         super Phase
  30
  31         redef fun process_nmodule(nmodule) do nmodule.do_literal(toolcontext)
  32 end
  33
  34 redef class AModule
  35         # Visit the module to compute the real value of the literal-related node of the AST.
  36         # Warnings and errors are displayed on the toolcontext.
  37         fun do_literal(toolcontext: ToolContext)
  38         do
  39                 var v = new LiteralVisitor(toolcontext)
  40                 v.enter_visit(self)
  41         end
  42 end
  43
  44 private class LiteralVisitor
  45         super Visitor
  46
  47         var toolcontext: ToolContext
  48
  49         init(toolcontext: ToolContext)
  50         do
  51                 self.toolcontext = toolcontext
  52         end
  53
  54         redef fun visit(n)
  55         do
  56                 n.accept_literal(self)
  57                 n.visit_all(self)
  58         end
  59 end
  60
  61 redef class ANode
  62         private fun accept_literal(v: LiteralVisitor) do end
  63 end
  64
  65 redef class AIntExpr
  66         # The value of the literal int once computed.
  67         var value: nullable Int
  68         redef fun accept_literal(v)
  69         do
  70                 self.value = self.n_number.text.to_i
  71         end
  72 end
  73
  74 redef class AFloatExpr
  75         # The value of the literal float once computed.
  76         var value: nullable Float
  77         redef fun accept_literal(v)
  78         do
  79                 self.value = self.n_float.text.to_f
  80         end
  81 end
  82
  83 redef class ACharExpr
  84         # The value of the literal char once computed.
  85         var value: nullable Char
  86         redef fun accept_literal(v)
  87         do
  88                 var txt = self.n_char.text.unescape_nit
  89                 if txt.length != 3 then
  90                         v.toolcontext.error(self.hot_location, "Invalid character literal {txt}")
  91                         return
  92                 end
  93                 self.value = txt[1]
  94         end
  95 end
  96
  97 redef class AStringFormExpr
  98         # The value of the literal string once computed.
  99         var value: nullable String
 100         redef fun accept_literal(v)
 101         do
 102                 var txt = self.n_string.text
 103                 var skip = 1
 104                 if txt[0] == txt[1] and txt.length >= 6 then skip = 3
 105                 self.value = txt.substring(skip, txt.length-(2*skip)).unescape_nit
 106         end
 107 end