in src/main/java/org/apache/xmlbeans/impl/regex/RegularExpression.java [489:639]
private Op compile(Token tok, Op next, boolean reverse) {
Op ret;
switch (tok.type) {
case Token.DOT:
ret = Op.createDot();
ret.next = next;
break;
case Token.CHAR:
ret = Op.createChar(tok.getChar());
ret.next = next;
break;
case Token.ANCHOR:
ret = Op.createAnchor(tok.getChar());
ret.next = next;
break;
case Token.RANGE:
case Token.NRANGE:
ret = Op.createRange(tok);
ret.next = next;
break;
case Token.CONCAT:
ret = next;
if (!reverse) {
for (int i = tok.size()-1; i >= 0; i --) {
ret = compile(tok.getChild(i), ret, false);
}
} else {
for (int i = 0; i < tok.size(); i ++) {
ret = compile(tok.getChild(i), ret, true);
}
}
break;
case Token.UNION:
Op.UnionOp uni = Op.createUnion(tok.size());
for (int i = 0; i < tok.size(); i ++) {
uni.addElement(compile(tok.getChild(i), next, reverse));
}
ret = uni; // ret.next is null.
break;
case Token.CLOSURE:
case Token.NONGREEDYCLOSURE:
Token child = tok.getChild(0);
int min = tok.getMin();
int max = tok.getMax();
if (min >= 0 && min == max) { // {n}
ret = next;
for (int i = 0; i < min; i ++) {
ret = compile(child, ret, reverse);
}
break;
}
if (min > 0 && max > 0)
max -= min;
if (max > 0) {
// X{2,6} -> XX(X(X(XX?)?)?)?
ret = next;
for (int i = 0; i < max; i ++) {
Op.ChildOp q = Op.createQuestion(tok.type == Token.NONGREEDYCLOSURE);
q.next = next;
q.setChild(compile(child, ret, reverse));
ret = q;
}
} else {
Op.ChildOp op;
if (tok.type == Token.NONGREEDYCLOSURE) {
op = Op.createNonGreedyClosure();
} else { // Token.CLOSURE
op = Op.createClosure(this.numberOfClosures++);
}
op.next = next;
op.setChild(compile(child, op, reverse));
ret = op;
}
if (min > 0) {
for (int i = 0; i < min; i ++) {
ret = compile(child, ret, reverse);
}
}
break;
case Token.EMPTY:
ret = next;
break;
case Token.STRING:
ret = Op.createString(tok.getString());
ret.next = next;
break;
case Token.BACKREFERENCE:
ret = Op.createBackReference(tok.getReferenceNumber());
ret.next = next;
break;
case Token.PAREN:
if (tok.getParenNumber() == 0) {
ret = compile(tok.getChild(0), next, reverse);
} else if (reverse) {
next = Op.createCapture(tok.getParenNumber(), next);
next = compile(tok.getChild(0), next, reverse);
ret = Op.createCapture(-tok.getParenNumber(), next);
} else {
next = Op.createCapture(-tok.getParenNumber(), next);
next = compile(tok.getChild(0), next, reverse);
ret = Op.createCapture(tok.getParenNumber(), next);
}
break;
case Token.LOOKAHEAD:
ret = Op.createLook(Op.LOOKAHEAD, next, compile(tok.getChild(0), null, false));
break;
case Token.NEGATIVELOOKAHEAD:
ret = Op.createLook(Op.NEGATIVELOOKAHEAD, next, compile(tok.getChild(0), null, false));
break;
case Token.LOOKBEHIND:
ret = Op.createLook(Op.LOOKBEHIND, next, compile(tok.getChild(0), null, true));
break;
case Token.NEGATIVELOOKBEHIND:
ret = Op.createLook(Op.NEGATIVELOOKBEHIND, next, compile(tok.getChild(0), null, true));
break;
case Token.INDEPENDENT:
ret = Op.createIndependent(next, compile(tok.getChild(0), null, reverse));
break;
case Token.MODIFIERGROUP:
ret = Op.createModifier(next, compile(tok.getChild(0), null, reverse),
((Token.ModifierToken)tok).getOptions(),
((Token.ModifierToken)tok).getOptionsMask());
break;
case Token.CONDITION:
Token.ConditionToken ctok = (Token.ConditionToken)tok;
int ref = ctok.refNumber;
Op condition = ctok.condition == null ? null : compile(ctok.condition, null, reverse);
Op yes = compile(ctok.yes, next, reverse);
Op no = ctok.no == null ? null : compile(ctok.no, next, reverse);
ret = Op.createCondition(next, ref, condition, yes, no);
break;
default:
throw new RuntimeException("Unknown token type: "+tok.type);
} // switch (tok.type)
return ret;
}