gcc/m2/gm2-compiler/SymbolKey.def

   1 (* SymbolKey.def binary tree operations for storing symbols.
   2
   3 Copyright (C) 2001-2024 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Modula-2; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  *)
  21
  22 DEFINITION MODULE SymbolKey ;
  23
  24 (*
  25    Author     : Gaius Mulley
  26    Title      : SymbolKey
  27    Date       : 4/3/87
  28    Description: Provides binary tree operations for storing symbols.
  29                 Used by the MODULE SymbolTable to provide scoping of symbols.
  30    Last update: Date: Wed 31-01-1990 Time: 18:20:32.63
  31                 Mon Aug 30 12:07:12 BST 1999
  32 *)
  33
  34 FROM SYSTEM IMPORT WORD ;
  35 FROM NameKey IMPORT Name ;
  36 EXPORT QUALIFIED NulKey, SymbolTree,
  37                  IsSymbol, PerformOperation,
  38                  InitTree, KillTree, GetSymKey, PutSymKey, DelSymKey,
  39                  IsEmptyTree,
  40                  DoesTreeContainAny, ForeachNodeDo, ContainsSymKey,
  41                  NoOfNodes, ForeachNodeConditionDo ;
  42
  43 CONST
  44    NulKey = 0 ;
  45
  46 TYPE
  47    SymbolTree ;
  48
  49    IsSymbol         = PROCEDURE (WORD) : BOOLEAN ;
  50    PerformOperation = PROCEDURE (WORD) ;
  51
  52
  53 (*
  54    InitTree - Initializes a SymbolTree pointed to by t.
  55 *)
  56
  57 PROCEDURE InitTree (VAR t: SymbolTree) ;
  58
  59
  60 (*
  61    KillTree - Destroys the SymbolTree pointed to by t.
  62 *)
  63
  64 PROCEDURE KillTree (VAR t: SymbolTree) ;
  65
  66
  67 (*
  68    GetSymKey - Searches the SymbolTree t for an entry NameKey. If
  69                found then the SymKey is returned. NulKey = not found.
  70 *)
  71
  72 PROCEDURE GetSymKey (t: SymbolTree; NameKey: Name) : WORD ;
  73
  74
  75 (*
  76    PutSymKey - Puts an symbol entry NameKey in the SymbolTree t.
  77                SymKey is the value stored with NameKey.
  78 *)
  79
  80 PROCEDURE PutSymKey (t: SymbolTree; NameKey: Name; SymKey: WORD) ;
  81
  82
  83 (*
  84    DelSymKey - Deletes a symbol entry NameKey in the SymbolTree t.
  85 *)
  86
  87 PROCEDURE DelSymKey (t: SymbolTree; NameKey: Name) ;
  88
  89
  90 (*
  91    IsEmptyTree - returns true if SymbolTree, t, is empty.
  92 *)
  93
  94 PROCEDURE IsEmptyTree (t: SymbolTree) : BOOLEAN ;
  95
  96
  97 (*
  98    DoesTreeContainAny - returns true if SymbolTree, t, contains any
  99                         symbols which in turn return true when procedure,
 100                         P, is called with a symbol as its parameter.
 101 *)
 102
 103 PROCEDURE DoesTreeContainAny (t: SymbolTree; P: IsSymbol) : BOOLEAN ;
 104
 105
 106 (*
 107    ForeachNodeDo - for each node in SymbolTree, t, a procedure, P,
 108                    is called with the node symbol as its parameter.
 109                    It traverse the tree in order.
 110 *)
 111
 112 PROCEDURE ForeachNodeDo (t: SymbolTree; P: PerformOperation) ;
 113
 114
 115 (*
 116    ContainsSymKey - return TRUE if tree, t, contains an entry for, NameKey.
 117 *)
 118
 119 PROCEDURE ContainsSymKey (t: SymbolTree; NameKey: Name) : BOOLEAN ;
 120
 121
 122 (*
 123    NoOfNodes - returns the number of nodes in the tree t.
 124 *)
 125
 126 PROCEDURE NoOfNodes (t: SymbolTree; condition: IsSymbol) : CARDINAL ;
 127
 128
 129 (*
 130    ForeachNodeConditionDo - traverse the tree t and for any node which satisfied
 131                             condition call P.
 132 *)
 133
 134 PROCEDURE ForeachNodeConditionDo (t: SymbolTree;
 135                                   condition: IsSymbol;
 136                                   P: PerformOperation) ;
 137
 138
 139 END SymbolKey.