mcs/class/Microsoft.JScript/Microsoft.JScript/IdentificationTable.cs

   1 //
   2 // ExecutionContext.cs: The stack of possible executions environments.
   3 //
   4 // Author:
   5 //      Cesar Lopez Nataren
   6 //
   7 // (C) 2003, Cesar Lopez Nataren
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Collections;
  32 using System.Text;
  33
  34 namespace Microsoft.JScript {
  35
  36         internal class IdentificationTable {
  37
  38                 internal Stack stack;
  39
  40                 internal IdentificationTable ()
  41                 {
  42                         stack = new Stack ();
  43                         stack.Push (new SymbolTable (null));
  44                 }
  45
  46                 internal void OpenBlock ()
  47                 {
  48                         SymbolTable parent = (SymbolTable) stack.Peek ();
  49                         stack.Push (new SymbolTable (parent));
  50                 }
  51
  52                 internal void CloseBlock ()
  53                 {
  54                         stack.Pop ();
  55                 }
  56
  57                 internal void Enter (string id, object decl)
  58                 {
  59                         ((SymbolTable) stack.Peek ()).Add (id , decl);
  60                 }
  61
  62                 internal void Remove (string id)
  63                 {
  64                         ((SymbolTable) stack.Peek ()).Remove (id);
  65                 }
  66                 //
  67                 // It'll return the object asociated with the 'id', if found.
  68                 //
  69                 internal object Contains (string id)
  70                 {
  71                         SymbolTable parent, current_scope = (SymbolTable) stack.Peek ();
  72                         object found = current_scope.Contains (id);
  73
  74                         if (found == null) {
  75                                 parent = current_scope.parent;
  76
  77                                 if (parent != null)
  78                                         found = parent.Contains (id);
  79                         }
  80                         return found;
  81                 }
  82
  83                 public override string ToString ()
  84                 {
  85                         StringBuilder sb = new StringBuilder ();
  86
  87                         int i, size = stack.Count;
  88
  89                         for (i = 0; i < size; i++)
  90                                 sb.Append (stack.Pop ().ToString ());
  91
  92                         return sb.ToString ();
  93                 }
  94
  95                 internal int num_of_locals {
  96                         get { return  ((SymbolTable) stack.Peek ()).size; }
  97                 }
  98
  99                 internal DictionaryEntry [] current_locals {
 100                         get { return  ((SymbolTable) stack.Peek ()).current_symbols; }
 101                 }
 102         }
 103 }