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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright (C) 2001 Gerwin Klein <lsf@jflex.de> *
* Copyright (C) 2001 Bernhard Rumpe <rumpe@in.tum.de> *
* All rights reserved. *
* *
* License: BSD *
* *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/**
* AST node for bool expressions
*/
class Tboolexp implements AST {
Texp exp1, exp2; // left and right subexpression
char kind; // '=', '<' and '!' for "<="
public Tboolexp(Texp e1, char k, Texp e2) {
exp1=e1;
kind=k;
exp2=e2;
}
public String toString() {
if (kind!='!')
return(""+exp1+kind+exp2);
else
return(exp1+"<="+exp2);
}
public void checkcontext(SymTab st) { // context conditions
exp1.checkcontext(st);
exp2.checkcontext(st);
}
public void prepInterp(SymTab st) { // set pointers and indices
exp1.prepInterp(st);
exp2.prepInterp(st);
}
public boolean interpret(int[] in, int[] par) {
int e1 = exp1.interpret(in,par);
int e2 = exp2.interpret(in,par);
switch(kind) {
case '=': return(e1==e2);
case '<': return(e1<e2);
case '!': return(e1<=e2);
}
return(false); // error
}
}
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