void Generator::generateNonGreedyQuantifier(JumpList& failures, GenerateAtomFunctor& functor, unsigned min, unsigned max)
{
JumpList atomFailedList;
JumpList alternativeFailedList;
// (0) Setup: Save, then init repeatCount.
push(repeatCount);
move(Imm32(0), repeatCount);
Jump start = jump();
// (4) Quantifier failed: No more atom reading possible.
Label quantifierFailed(this);
pop(repeatCount);
failures.append(jump());
// (3) Alternative failed: If we can, read another atom, then fall through to (2) to try again.
Label alternativeFailed(this);
pop(index);
if (max != Quantifier::Infinity)
je32(repeatCount, Imm32(max), quantifierFailed);
// (1) Read an atom.
if (min)
start.link(this);
Label readAtom(this);
functor.generateAtom(this, atomFailedList);
atomFailedList.linkTo(quantifierFailed, this);
add32(Imm32(1), repeatCount);
// (2) Keep reading if we're under the minimum.
if (min > 1)
jl32(repeatCount, Imm32(min), readAtom);
// (3) Test the rest of the alternative.
if (!min)
start.link(this);
push(index);
m_parser.parseAlternative(alternativeFailedList);
alternativeFailedList.linkTo(alternativeFailed, this);
pop();
pop(repeatCount);
}
void Generator::generateGreedyQuantifier(JumpList& failures, GenerateAtomFunctor& functor, unsigned min, unsigned max)
{
if (!max)
return;
JumpList doneReadingAtomsList;
JumpList alternativeFailedList;
// (0) Setup: Save, then init repeatCount.
push(repeatCount);
move(Imm32(0), repeatCount);
// (1) Greedily read as many copies of the atom as possible, then jump to (2).
Label readAtom(this);
functor.generateAtom(this, doneReadingAtomsList);
add32(Imm32(1), repeatCount);
if (max == Quantifier::Infinity)
jump(readAtom);
else if (max == 1)
doneReadingAtomsList.append(jump());
else {
jne32(repeatCount, Imm32(max), readAtom);
doneReadingAtomsList.append(jump());
}
// (5) Quantifier failed: No more backtracking possible.
Label quantifierFailed(this);
pop(repeatCount);
failures.append(jump());
// (4) Alternative failed: Backtrack, then fall through to (2) to try again.
Label alternativeFailed(this);
pop(index);
functor.backtrack(this);
sub32(Imm32(1), repeatCount);
// (2) Verify that we have enough atoms.
doneReadingAtomsList.link(this);
jl32(repeatCount, Imm32(min), quantifierFailed);
// (3) Test the rest of the alternative.
push(index);
m_parser.parseAlternative(alternativeFailedList);
alternativeFailedList.linkTo(alternativeFailed, this);
pop();
pop(repeatCount);
}
