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LibJS: Implement RegExp.prototype.hasIndices proposal

Browse source 
https://tc39.es/proposal-regexp-match-indices/
This commit is contained in:
Timothy Flynn 2021-07-09 19:51:56 -04:00 • committed by Linus Groh
parent d1e06b00e3
commit 6c67de8186
Notes: sideshowbarker 2024-07-18 09:25:07 +09:00
3 changed files with 152 additions and 3 deletions
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1
Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
View file

@ -198,6 +198,7 @@ namespace JS {
P(includes) \
P(index) \
P(indexOf) \
P(indices) \
P(info) \
P(input) \
P(instant) \

101
Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp
View file

@ -103,6 +103,79 @@ static void increment_last_index(GlobalObject& global_object, Object& regexp_obj
regexp_object.set(vm.names.lastIndex, Value(last_index), true);
}
// 1.1.2.1 Match Records, https://tc39.es/proposal-regexp-match-indices/#sec-match-records
struct Match {
static Match create(regex::Match const& match)
{
return { match.global_offset, match.global_offset + match.view.length() };
}
size_t start_index { 0 };
size_t end_index { 0 };
};
// 1.1.4.1.4 GetMatchIndicesArray ( S, match ), https://tc39.es/proposal-regexp-match-indices/#sec-getmatchindicesarray
static Value get_match_indices_array(GlobalObject& global_object, String const& string, Match const& match)
{
VERIFY(match.start_index <= string.length());
VERIFY(match.end_index >= match.start_index);
VERIFY(match.end_index <= string.length());
return Array::create_from(global_object, { Value(match.start_index), Value(match.end_index) });
}
// 1.1.4.1.5 MakeIndicesArray ( S , indices, groupNames, hasGroups ), https://tc39.es/proposal-regexp-match-indices/#sec-makeindicesarray
static Value make_indices_array(GlobalObject& global_object, String const& string, Vector<Optional<Match>> const& indices, HashMap<String, Match> const& group_names, bool has_groups)
{
// Note: This implementation differs from the spec, but has the same behavior.
//
// The spec dictates that [[RegExpMatcher]] results should contain one list of capture groups,
// where each entry holds its group name (if it has one). However, LibRegex stores named capture
// groups in a separate hash map.
//
// The spec further specifies that the group names provided to this abstraction align with the
// provided indices starting at indices[1], where any entry in indices that does not have a group
// name is undefined in the group names list. But, the undefined groups names are then just
// dropped when copying them to the output array.
//
// Therefore, this implementation tracks the group names without the assertion that the group
// names align with the indices. The end result is the same.
auto& vm = global_object.vm();
auto* array = Array::create(global_object, indices.size());
if (vm.exception())
return {};
auto groups = has_groups ? Object::create(global_object, nullptr) : js_undefined();
for (size_t i = 0; i < indices.size(); ++i) {
auto const& match_indices = indices[i];
auto match_indices_array = js_undefined();
if (match_indices.has_value())
match_indices_array = get_match_indices_array(global_object, string, *match_indices);
array->create_data_property(i, match_indices_array);
if (vm.exception())
return {};
}
for (auto const& entry : group_names) {
auto match_indices_array = get_match_indices_array(global_object, string, entry.value);
groups.as_object().create_data_property(entry.key, match_indices_array);
if (vm.exception())
return {};
}
array->create_data_property(vm.names.groups, groups);
if (vm.exception())
return {};
return array;
}
// 22.2.5.2.2 RegExpBuiltinExec ( R, S ), https://tc39.es/ecma262/#sec-regexpbuiltinexec
static Value regexp_builtin_exec(GlobalObject& global_object, RegExpObject& regexp_object, String const& string)
{
@ -119,6 +192,8 @@ static Value regexp_builtin_exec(GlobalObject& global_object, RegExpObject& rege
auto& regex = regexp_object.regex();
bool global = regex.options().has_flag_set(ECMAScriptFlags::Global);
bool sticky = regex.options().has_flag_set(ECMAScriptFlags::Sticky);
bool has_indices = regexp_object.flags().find('d').has_value();
if (!global && !sticky)
last_index = 0;
@ -175,24 +250,44 @@ static Value regexp_builtin_exec(GlobalObject& global_object, RegExpObject& rege
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()));
Vector<Optional<Match>> indices { Match::create(match) };
HashMap<String, Match> group_names;
for (size_t i = 0; i < result.n_capture_groups; ++i) {
auto capture_value = js_undefined();
auto& capture = result.capture_group_matches[0][i + 1];
if (!capture.view.is_null())
if (capture.view.is_null()) {
indices.append({});
} else {
capture_value = js_string(vm, capture.view.to_string());
indices.append(Match::create(capture));
}
array->create_data_property_or_throw(i + 1, capture_value);
}
bool has_groups = result.n_named_capture_groups > 0;
Value groups = js_undefined();
if (result.n_named_capture_groups > 0) {
if (has_groups) {
auto groups_object = Object::create(global_object, nullptr);
for (auto& entry : result.named_capture_group_matches[0])
for (auto& entry : result.named_capture_group_matches[0]) {
groups_object->create_data_property_or_throw(entry.key, js_string(vm, entry.value.view.to_string()));
group_names.set(entry.key, Match::create(entry.value));
}
groups = move(groups_object);
}
array->create_data_property_or_throw(vm.names.groups, groups);
if (has_indices) {
auto indices_array = make_indices_array(global_object, string, indices, group_names, has_groups);
array->create_data_property(vm.names.indices, indices_array);
if (vm.exception())
return {};
}
return array;
}

53
Userland/Libraries/LibJS/Tests/builtins/RegExp/RegExp.prototype.hasIndices.js Normal file
View file

@ -0,0 +1,53 @@
test("basic functionality", () => {
const str = "foo bar foo";
var regex = new RegExp("bar");
expect(regex.hasIndices).toBeFalse();
expect(regex.exec(str).indices).toBeUndefined();
regex = new RegExp("foo", "gd");
expect(regex.hasIndices).toBeTrue();
expect(regex.exec(str).indices[0]).toEqual([0, 3]);
expect(regex.exec(str).indices[0]).toEqual([8, 11]);
regex = new RegExp("(foo)", "gd");
expect(regex.hasIndices).toBeTrue();
{
var result = regex.exec(str).indices;
expect(result.length).toBe(2);
expect(result[0]).toEqual([0, 3]);
expect(result[1]).toEqual([0, 3]);
expect(result.groups).toBeUndefined();
}
{
var result = regex.exec(str).indices;
expect(result.length).toBe(2);
expect(result[0]).toEqual([8, 11]);
expect(result[1]).toEqual([8, 11]);
expect(result.groups).toBeUndefined();
}
regex = new RegExp("(?<group_name>foo)", "gd");
expect(regex.hasIndices).toBeTrue();
{
var result = regex.exec(str).indices;
expect(result.length).toBe(2);
expect(result[0]).toEqual([0, 3]);
expect(result[1]).toEqual([0, 3]);
expect(result.groups).toEqual({ group_name: [0, 3] });
}
{
var result = regex.exec(str).indices;
expect(result.length).toBe(2);
expect(result[0]).toEqual([8, 11]);
expect(result[1]).toEqual([8, 11]);
expect(result.groups).toEqual({ group_name: [8, 11] });
}
regex = /(?<keyword>let|const|var)\s+(?<id>[a-zA-Z_$][0-9a-zA-Z_$]*)/d;
expect(regex.hasIndices).toBeTrue();
{
var result = regex.exec("let foo").indices;
expect(result.groups).toEqual({ keyword: [0, 3], id: [4, 7] });
}
});