tools/lexer/jflex-1.4/examples/interpreter/Tprogram.java

   1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
   2  * Copyright (C) 2001       Gerwin Klein <lsf@jflex.de>                    *
   3  * Copyright (C) 2001       Bernhard Rumpe <rumpe@in.tum.de>               *
   4  * All rights reserved.                                                    *
   5  *                                                                         *
   6  * This program is free software; you can redistribute it and/or modify    *
   7  * it under the terms of the GNU General Public License. See the file      *
   8  * COPYRIGHT for more information.                                         *
   9  *                                                                         *
  10  * This program is distributed in the hope that it will be useful,         *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
  13  * GNU General Public License for more details.                            *
  14  *                                                                         *
  15  * You should have received a copy of the GNU General Public License along *
  16  * with this program; if not, write to the Free Software Foundation, Inc., *
  17  * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA                 *
  18  *                                                                         *
  19  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
  20
  21
  22 /**
  23  * AST node for the whole program (top node).
  24  *
  25  * Also contains two symbol tables, one for input variables,
  26  * one for function names.
  27  *
  28  * All operations like context check, symbol table build up
  29  * etc. start here.
  30  */
  31 class Tprogram implements AST {
  32
  33   Tparlist parlist;           // input variables
  34   Tdekllist dekllist;         // function declarations
  35   Texplist explist;           // result expressions
  36   Texplist arguments;         // input values
  37
  38   public Tprogram(Tparlist p, Tdekllist d, Texplist e, Texplist a) {
  39     parlist=p;
  40     dekllist=d;
  41     explist=e;
  42     arguments=a;
  43   }
  44
  45   public String toString() {
  46     return("Program:\n=============\ninput "+parlist+
  47            "\nfunctions\n"+dekllist+"\noutput "+explist+
  48            "\narguments "+arguments+"\nend");
  49   }
  50
  51   SymTab inputs;      // table of input variables
  52   SymTab functions;   // table of functions
  53
  54   public void setSymtabs() {          // calculate symbol table entries
  55     inputs = new SymTab();            // set input variables
  56     parlist.setSymtab(inputs, true, 0);
  57     functions = new SymTab(inputs);
  58     dekllist.setSymtab(functions);
  59   }
  60
  61   public void printSymtabs() {
  62     System.out.print("Input variables-\n"+inputs);
  63     System.out.print("Functions-\n"+functions);
  64     dekllist.printSymtabs();
  65   }
  66
  67   public void checkcontext() {
  68     dekllist.checkcontext();          // CoCo (DefFun,DefVar,Arity)
  69                                       // in function bodies
  70     explist.checkcontext(functions);  // CoCo (DefFun,DefVar,Arity)
  71                                       // in result expressions
  72     arguments.checkcontext(new SymTab()); // CoCo  (constants)
  73                                           // in arguments
  74     if (arguments.length()!=inputs.size())
  75       Main.error("Argument list and input variables list differ!");
  76   }
  77
  78   public void prepInterp() {          // set pointers and indices
  79     dekllist.prepInterp(functions);
  80     explist.prepInterp(functions);
  81   }
  82
  83   public void interpret() {
  84     int[] inputEnv = new int[inputs.size()];      // set input
  85
  86     arguments.interpret(null,null,inputEnv,0);
  87
  88     System.out.println("Result:\n=============");
  89
  90     int[] ergebnis = new int[explist.length()];
  91     explist.interpret(inputEnv,null,ergebnis,0);  // calculate result
  92
  93     int i;
  94     for (i=explist.length()-1; i > 0; i--)
  95       System.out.print(ergebnis[i]+",  ");
  96     System.out.println(ergebnis[i]);
  97   }
  98 }
  99