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LibRegex: Implement lookaround in ERE

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This commit is contained in:
Ali Mohammad Pur 2021-07-13 02:16:09 +04:30 • committed by Gunnar Beutner
parent 5f4e1338a1
commit 6e35b94034
1 changed files with 30 additions and 7 deletions
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37
Userland/Libraries/LibRegex/RegexParser.cpp
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@ -218,7 +218,7 @@ ALWAYS_INLINE bool AbstractPosixParser::parse_bracket_expression(Vector<CompareT
// FIXME: Parse collating element, this is needed when we have locale support // FIXME: Parse collating element, this is needed when we have locale support
// This could have impact on length parameter, I guess. // This could have impact on length parameter, I guess.
VERIFY_NOT_REACHED(); set_error(Error::InvalidCollationElement);
consume(TokenType::Period, Error::InvalidCollationElement); consume(TokenType::Period, Error::InvalidCollationElement);
consume(TokenType::RightBracket, Error::MismatchingBracket); consume(TokenType::RightBracket, Error::MismatchingBracket);
@ -227,7 +227,7 @@ ALWAYS_INLINE bool AbstractPosixParser::parse_bracket_expression(Vector<CompareT
consume(); consume();
// FIXME: Parse collating element, this is needed when we have locale support // FIXME: Parse collating element, this is needed when we have locale support
// This could have impact on length parameter, I guess. // This could have impact on length parameter, I guess.
VERIFY_NOT_REACHED(); set_error(Error::InvalidCollationElement);
consume(TokenType::EqualSign, Error::InvalidCollationElement); consume(TokenType::EqualSign, Error::InvalidCollationElement);
consume(TokenType::RightBracket, Error::MismatchingBracket); consume(TokenType::RightBracket, Error::MismatchingBracket);
@ -711,6 +711,13 @@ ALWAYS_INLINE bool PosixExtendedParser::parse_sub_expression(ByteCode& stack, si
return false; return false;
if (match(TokenType::LeftParen)) { if (match(TokenType::LeftParen)) {
enum GroupMode {
Normal,
Lookahead,
NegativeLookahead,
Lookbehind,
NegativeLookbehind,
} group_mode { Normal };
consume(); consume();
Optional<StringView> capture_group_name; Optional<StringView> capture_group_name;
bool prevent_capture_group = false; bool prevent_capture_group = false;
@ -739,16 +746,16 @@ ALWAYS_INLINE bool PosixExtendedParser::parse_sub_expression(ByteCode& stack, si
} else if (match(TokenType::EqualSign)) { // positive lookahead } else if (match(TokenType::EqualSign)) { // positive lookahead
consume(); consume();
VERIFY_NOT_REACHED(); group_mode = Lookahead;
} else if (consume("!")) { // negative lookahead } else if (consume("!")) { // negative lookahead
VERIFY_NOT_REACHED(); group_mode = NegativeLookahead;
} else if (consume("<")) { } else if (consume("<")) {
if (match(TokenType::EqualSign)) { // positive lookbehind if (match(TokenType::EqualSign)) { // positive lookbehind
consume(); consume();
VERIFY_NOT_REACHED(); group_mode = Lookbehind;
} }
if (consume("!")) // negative lookbehind if (consume("!")) // negative lookbehind
VERIFY_NOT_REACHED(); group_mode = NegativeLookbehind;
} else { } else {
return set_error(Error::InvalidRepetitionMarker); return set_error(Error::InvalidRepetitionMarker);
} }
@ -766,7 +773,23 @@ ALWAYS_INLINE bool PosixExtendedParser::parse_sub_expression(ByteCode& stack, si
if (!parse_root(capture_group_bytecode, length)) if (!parse_root(capture_group_bytecode, length))
return set_error(Error::InvalidPattern); return set_error(Error::InvalidPattern);
bytecode.extend(move(capture_group_bytecode)); switch (group_mode) {
case Normal:
bytecode.extend(move(capture_group_bytecode));
break;
case Lookahead:
bytecode.insert_bytecode_lookaround(move(capture_group_bytecode), ByteCode::LookAroundType::LookAhead, length);
break;
case NegativeLookahead:
bytecode.insert_bytecode_lookaround(move(capture_group_bytecode), ByteCode::LookAroundType::NegatedLookAhead, length);
break;
case Lookbehind:
bytecode.insert_bytecode_lookaround(move(capture_group_bytecode), ByteCode::LookAroundType::LookBehind, length);
break;
case NegativeLookbehind:
bytecode.insert_bytecode_lookaround(move(capture_group_bytecode), ByteCode::LookAroundType::NegatedLookBehind, length);
break;
}
consume(TokenType::RightParen, Error::MismatchingParen); consume(TokenType::RightParen, Error::MismatchingParen);