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LibJS: Implement RegExpBuiltinExec closer to the spec

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Our RegExpBuiltinExec implementation differed from the spec in some
areas such as handling of the sticky/global flags and updating the
lastIndex property.
This commit is contained in:
Timothy Flynn 2021-07-09 09:37:54 -04:00 • committed by Linus Groh
parent 0f0ac37b56
commit 43918b0104
1 changed files with 56 additions and 26 deletions
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82
Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp
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@ -107,39 +107,69 @@ static Value regexp_builtin_exec(GlobalObject& global_object, RegExpObject& rege
// FIXME: This should try using internal slots [[RegExpMatcher]], [[OriginalFlags]], etc.
auto& vm = global_object.vm();
// RegExps without "global" and "sticky" always start at offset 0.
if (!regexp_object.regex().options().has_flag_set((ECMAScriptFlags)regex::AllFlags::Internal_Stateful)) {
regexp_object.set(vm.names.lastIndex, Value(0), true);
auto last_index_value = regexp_object.get(vm.names.lastIndex);
if (vm.exception())
return {};
auto last_index = last_index_value.to_length(global_object);
if (vm.exception())
return {};
auto& regex = regexp_object.regex();
bool global = regex.options().has_flag_set(ECMAScriptFlags::Global);
bool sticky = regex.options().has_flag_set(ECMAScriptFlags::Sticky);
if (!global && !sticky)
last_index = 0;
RegexResult result;
while (true) {
if (last_index > string.length()) {
if (global || sticky) {
regexp_object.set(vm.names.lastIndex, Value(0), true);
if (vm.exception())
return {};
}
return js_null();
}
regex.start_offset = last_index;
result = regex.match(string);
if (result.success)
break;
if (sticky) {
regexp_object.set(vm.names.lastIndex, Value(0), true);
if (vm.exception())
return {};
return js_null();
}
// FIXME: Implement AdvanceStringIndex to take Unicode code points into account - https://tc39.es/ecma262/#sec-advancestringindex
++last_index;
}
auto& match = result.matches[0];
// https://tc39.es/ecma262/#sec-notation:
// The endIndex is one plus the index of the last input character matched so far by the pattern.
auto end_index = match.global_offset + match.view.length();
// FIXME: Do code point index correction if the Unicode flag is set.
if (global || sticky) {
regexp_object.set(vm.names.lastIndex, Value(end_index), true);
if (vm.exception())
return {};
}
auto last_index = regexp_object.get(vm.names.lastIndex);
if (vm.exception())
return {};
regexp_object.regex().start_offset = last_index.to_length(global_object);
if (vm.exception())
return {};
auto result = regexp_object.regex().match(string);
// The 'lastIndex' property is reset on failing tests (if 'global')
if (!result.success && regexp_object.regex().options().has_flag_set(ECMAScriptFlags::Global))
regexp_object.regex().start_offset = 0;
regexp_object.set(vm.names.lastIndex, Value(regexp_object.regex().start_offset), true);
if (vm.exception())
return {};
if (!result.success)
return js_null();
auto& match = result.matches[0];
// FIXME: Do code point index correction if the Unicode flag is set.
auto* array = Array::create(global_object, result.n_capture_groups + 1);
if (vm.exception())
return {};
array->create_data_property_or_throw(vm.names.index, Value((i32)match.global_offset));
array->create_data_property_or_throw(vm.names.index, Value(match.global_offset));
array->create_data_property_or_throw(vm.names.input, js_string(vm, string));
array->create_data_property_or_throw(0, js_string(vm, match.view.to_string()));