4 static public final int EXPR=0;
5 static public final int POSITION=1;
6 static public final int ABSTRACT=2;
14 public String toString() {
16 return leftexpr.name()+opcode.toString()+rightexpr.name();
17 else if (type==POSITION)
18 return leftexpr.name()+opcode.toString()+"Position("+String.valueOf(rightposition)+")";
19 else if (type==ABSTRACT) {
20 if (negate) return "!"+leftexpr.name();
21 else return leftexpr.name();
22 } else throw new Error("Unrecognized type");
25 public Updates(Expr lexpr, Expr rexpr, Opcode op, boolean negate) {
29 /* remove negation through opcode translation */
32 else if (op==Opcode.GE)
34 else if (op==Opcode.EQ)
36 else if (op==Opcode.NE)
38 else if (op==Opcode.LT)
40 else if (op==Opcode.LE)
48 if (leftexpr instanceof VarExpr)
53 VarDescriptor getVar() {
55 return ((VarExpr)leftexpr).getVar();
56 } else if (isField()) {
58 for(;e instanceof DotExpr;e=((DotExpr)e).getExpr()) ;
59 return ((VarExpr)e).getVar();
61 System.out.println(toString());
62 throw new Error("Unrecognized Update");
66 Descriptor getDescriptor() {
68 return ((VarExpr)leftexpr).getVar();
69 } else if (isField()) {
70 return ((DotExpr)leftexpr).getField();
72 System.out.println(toString());
73 throw new Error("Unrecognized Update");
78 if (leftexpr instanceof DotExpr) {
79 assert ((DotExpr)leftexpr).getIndex()==null;
86 return type==Updates.EXPR;
94 public Updates(Expr lexpr, Expr rexpr) {
101 public Updates(Expr lexpr, int rpos) {
104 type=Updates.POSITION;
108 boolean isAbstract() {
109 return type==Updates.ABSTRACT;
112 public Updates(Expr lexpr,boolean negates) {
114 type=Updates.ABSTRACT;
119 public int getType() {
122 public Expr getLeftExpr() {
125 public int getRightPos() {
126 assert type==Updates.POSITION;
127 return rightposition;
129 public Expr getRightExpr() {
130 assert type==Updates.EXPR;