Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89 Commit: 93712b24bf Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256 Reviewed-by: https://github.com/sideshowbarker
2025-07-31 05:09:12 +00:00 · 2024-11-09 12:25:08 -05:00 · 2024-11-09 12:25:08 -05:00 · 93712b24bf · 2024-11-10 11:51:52 +00:00
commit 93712b24bf
parent 950e819ee7
4547 changed files with 104 additions and 113 deletions
--- a/Libraries/LibWeb/SVG/AttributeParser.cpp
+++ b/Libraries/LibWeb/SVG/AttributeParser.cpp
@ -0,0 +1,746 @@
+/*
+ * Copyright (c) 2020, Matthew Olsson <mattco@serenityos.org>
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ * Copyright (c) 2023, MacDue <macdue@dueutil.tech>
+ * Copyright (c) 2024, Tim Ledbetter <timledbetter@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "AttributeParser.h"
+#include <AK/FloatingPointStringConversions.h>
+#include <AK/GenericShorthands.h>
+#include <AK/StringBuilder.h>
+#include <ctype.h>
+
+namespace Web::SVG {
+
+AttributeParser::AttributeParser(StringView source)
+    : m_lexer(source)
+{
+}
+
+Optional<Vector<Transform>> AttributeParser::parse_transform(StringView input)
+{
+    AttributeParser parser { input };
+    return parser.parse_transform();
+}
+
+Vector<PathInstruction> AttributeParser::parse_path_data(StringView input)
+{
+    AttributeParser parser { input };
+    parser.parse_whitespace();
+    while (!parser.done()) {
+        auto maybe_error = parser.parse_drawto();
+        if (maybe_error.is_error())
+            break;
+    }
+    if (!parser.m_instructions.is_empty() && parser.m_instructions[0].type != PathInstructionType::Move) {
+        // Invalid. "A path data segment (if there is one) must begin with a "moveto" command."
+        return {};
+    }
+    return parser.m_instructions;
+}
+
+Optional<float> AttributeParser::parse_coordinate(StringView input)
+{
+    AttributeParser parser { input };
+    parser.parse_whitespace();
+    auto result_or_error = parser.parse_coordinate();
+    if (result_or_error.is_error())
+        return {};
+    parser.parse_whitespace();
+    if (parser.done())
+        return result_or_error.value();
+    return {};
+}
+
+Optional<float> AttributeParser::parse_length(StringView input)
+{
+    AttributeParser parser { input };
+    parser.parse_whitespace();
+    auto result_or_error = parser.parse_length();
+    if (result_or_error.is_error())
+        return {};
+    parser.parse_whitespace();
+    if (parser.done())
+        return result_or_error.value();
+
+    return {};
+}
+
+float NumberPercentage::resolve_relative_to(float length) const
+{
+    if (!m_is_percentage)
+        return m_value;
+    return m_value * length;
+}
+
+Optional<NumberPercentage> AttributeParser::parse_number_percentage(StringView input)
+{
+    AttributeParser parser { input };
+    parser.parse_whitespace();
+
+    auto number_or_error = parser.parse_number();
+    if (number_or_error.is_error())
+        return {};
+    bool is_percentage = parser.match('%');
+    if (is_percentage)
+        parser.consume();
+    parser.parse_whitespace();
+    if (parser.done())
+        return NumberPercentage(number_or_error.value(), is_percentage);
+
+    return {};
+}
+
+Optional<float> AttributeParser::parse_positive_length(StringView input)
+{
+    // FIXME: Where this is used, the spec usually (always?) says "A negative value is an error (see Error processing)."
+    //        So, implement error processing! Maybe this should return ErrorOr.
+    auto result = parse_length(input);
+    if (result.has_value() && result.value() < 0)
+        result.clear();
+    return result;
+}
+
+Vector<Gfx::FloatPoint> AttributeParser::parse_points(StringView input)
+{
+    AttributeParser parser { input };
+
+    parser.parse_whitespace();
+
+    auto coordinate_pair_sequence_or_error = parser.parse_coordinate_pair_sequence();
+    if (coordinate_pair_sequence_or_error.is_error())
+        return {};
+
+    auto coordinate_pair_sequence = coordinate_pair_sequence_or_error.release_value();
+
+    // FIXME: This is awkward. Can we return Gfx::FloatPoints from some of these parsing methods instead of Vector<float>?
+    Vector<Gfx::FloatPoint> points;
+    points.ensure_capacity(coordinate_pair_sequence.size());
+
+    for (auto const& pair : coordinate_pair_sequence)
+        points.empend(pair[0], pair[1]);
+
+    return points;
+}
+
+ErrorOr<void> AttributeParser::parse_drawto()
+{
+    if (match('M') || match('m')) {
+        return parse_moveto();
+    } else if (match('Z') || match('z')) {
+        parse_closepath();
+        return {};
+    } else if (match('L') || match('l')) {
+        return parse_lineto();
+    } else if (match('H') || match('h')) {
+        return parse_horizontal_lineto();
+    } else if (match('V') || match('v')) {
+        return parse_vertical_lineto();
+    } else if (match('C') || match('c')) {
+        return parse_curveto();
+    } else if (match('S') || match('s')) {
+        return parse_smooth_curveto();
+    } else if (match('Q') || match('q')) {
+        return parse_quadratic_bezier_curveto();
+    } else if (match('T') || match('t')) {
+        return parse_smooth_quadratic_bezier_curveto();
+    } else if (match('A') || match('a')) {
+        return parse_elliptical_arc();
+    }
+
+    dbgln("AttributeParser::parse_drawto failed to match: '{}'", ch());
+    return Error::from_string_literal("Invalid drawto command");
+}
+
+// https://www.w3.org/TR/SVG2/paths.html#PathDataMovetoCommands
+ErrorOr<void> AttributeParser::parse_moveto()
+{
+    bool absolute = consume() == 'M';
+    parse_whitespace();
+
+    bool is_first = true;
+    for (auto& pair : TRY(parse_coordinate_pair_sequence())) {
+        // NOTE: "M 1 2 3 4" is equivalent to "M 1 2 L 3 4".
+        auto type = is_first ? PathInstructionType::Move : PathInstructionType::Line;
+        m_instructions.append({ type, absolute, pair });
+        is_first = false;
+    }
+
+    return {};
+}
+
+void AttributeParser::parse_closepath()
+{
+    bool absolute = consume() == 'Z';
+    parse_whitespace();
+    m_instructions.append({ PathInstructionType::ClosePath, absolute, {} });
+}
+
+ErrorOr<void> AttributeParser::parse_lineto()
+{
+    bool absolute = consume() == 'L';
+    parse_whitespace();
+    for (auto& pair : TRY(parse_coordinate_pair_sequence()))
+        m_instructions.append({ PathInstructionType::Line, absolute, pair });
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_horizontal_lineto()
+{
+    bool absolute = consume() == 'H';
+    parse_whitespace();
+    for (auto coordinate : TRY(parse_coordinate_sequence()))
+        m_instructions.append({ PathInstructionType::HorizontalLine, absolute, { coordinate } });
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_vertical_lineto()
+{
+    bool absolute = consume() == 'V';
+    parse_whitespace();
+    for (auto coordinate : TRY(parse_coordinate_sequence()))
+        m_instructions.append({ PathInstructionType::VerticalLine, absolute, { coordinate } });
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_curveto()
+{
+    bool absolute = consume() == 'C';
+    parse_whitespace();
+
+    while (true) {
+        m_instructions.append({ PathInstructionType::Curve, absolute, TRY(parse_coordinate_pair_triplet()) });
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_coordinate())
+            break;
+    }
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_smooth_curveto()
+{
+    bool absolute = consume() == 'S';
+    parse_whitespace();
+
+    while (true) {
+        m_instructions.append({ PathInstructionType::SmoothCurve, absolute, TRY(parse_coordinate_pair_double()) });
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_coordinate())
+            break;
+    }
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_quadratic_bezier_curveto()
+{
+    bool absolute = consume() == 'Q';
+    parse_whitespace();
+
+    while (true) {
+        m_instructions.append({ PathInstructionType::QuadraticBezierCurve, absolute, TRY(parse_coordinate_pair_double()) });
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_coordinate())
+            break;
+    }
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_smooth_quadratic_bezier_curveto()
+{
+    bool absolute = consume() == 'T';
+    parse_whitespace();
+
+    while (true) {
+        m_instructions.append({ PathInstructionType::SmoothQuadraticBezierCurve, absolute, TRY(parse_coordinate_pair()) });
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_coordinate())
+            break;
+    }
+
+    return {};
+}
+
+ErrorOr<void> AttributeParser::parse_elliptical_arc()
+{
+    bool absolute = consume() == 'A';
+    parse_whitespace();
+
+    while (true) {
+        auto argument = TRY(parse_elliptical_arc_argument());
+        m_instructions.append({ PathInstructionType::EllipticalArc, absolute, move(argument) });
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_coordinate())
+            break;
+    }
+
+    return {};
+}
+
+ErrorOr<float> AttributeParser::parse_length()
+{
+    // https://www.w3.org/TR/SVG11/types.html#DataTypeLength
+    return parse_number();
+}
+
+ErrorOr<float> AttributeParser::parse_coordinate()
+{
+    // https://www.w3.org/TR/SVG11/types.html#DataTypeCoordinate
+    // coordinate ::= length
+    return parse_length();
+}
+
+ErrorOr<Vector<float>> AttributeParser::parse_coordinate_pair()
+{
+    Vector<float> coordinates;
+    coordinates.append(TRY(parse_coordinate()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    coordinates.append(TRY(parse_coordinate()));
+    return coordinates;
+}
+
+ErrorOr<Vector<float>> AttributeParser::parse_coordinate_sequence()
+{
+    Vector<float> sequence;
+    bool is_first = true;
+    while (true) {
+        auto coordinate_or_error = parse_coordinate();
+        if (coordinate_or_error.is_error()) {
+            if (is_first)
+                return Error::from_string_literal("Expected coordinate sequence");
+        }
+        is_first = false;
+        sequence.append(coordinate_or_error.release_value());
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_comma_whitespace() && !match_coordinate())
+            break;
+    }
+    return sequence;
+}
+
+ErrorOr<Vector<Vector<float>>> AttributeParser::parse_coordinate_pair_sequence()
+{
+    Vector<Vector<float>> sequence;
+    bool is_first = true;
+    while (true) {
+        auto coordinate_pair_or_error = parse_coordinate_pair();
+        if (coordinate_pair_or_error.is_error()) {
+            if (is_first)
+                return Error::from_string_literal("Expected coordinate pair sequence");
+            break;
+        }
+        is_first = false;
+        sequence.append(coordinate_pair_or_error.release_value());
+        if (match_comma_whitespace())
+            parse_comma_whitespace();
+        if (!match_comma_whitespace() && !match_coordinate())
+            break;
+    }
+    return sequence;
+}
+
+ErrorOr<Vector<float>> AttributeParser::parse_coordinate_pair_double()
+{
+    Vector<float> coordinates;
+    coordinates.extend(TRY(parse_coordinate_pair()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    coordinates.extend(TRY(parse_coordinate_pair()));
+    return coordinates;
+}
+
+ErrorOr<Vector<float>> AttributeParser::parse_coordinate_pair_triplet()
+{
+    Vector<float> coordinates;
+    coordinates.extend(TRY(parse_coordinate_pair()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    coordinates.extend(TRY(parse_coordinate_pair()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    coordinates.extend(TRY(parse_coordinate_pair()));
+    return coordinates;
+}
+
+ErrorOr<Vector<float>> AttributeParser::parse_elliptical_arc_argument()
+{
+    Vector<float> numbers;
+    numbers.append(TRY(parse_number()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    numbers.append(TRY(parse_number()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    numbers.append(TRY(parse_number()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    numbers.append(TRY(parse_flag()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    numbers.append(TRY(parse_flag()));
+    if (match_comma_whitespace())
+        parse_comma_whitespace();
+    numbers.extend(TRY(parse_coordinate_pair()));
+
+    return numbers;
+}
+
+void AttributeParser::parse_whitespace(bool must_match_once)
+{
+    bool matched = false;
+    while (!done() && match_whitespace()) {
+        consume();
+        matched = true;
+    }
+
+    VERIFY(!must_match_once || matched);
+}
+
+void AttributeParser::parse_comma_whitespace()
+{
+    if (match(',')) {
+        consume();
+        parse_whitespace();
+    } else {
+        parse_whitespace(1);
+        if (match(','))
+            consume();
+        parse_whitespace();
+    }
+}
+
+// https://www.w3.org/TR/SVG11/types.html#DataTypeNumber
+ErrorOr<float> AttributeParser::parse_number()
+{
+    auto sign = parse_sign();
+    return sign * TRY(parse_nonnegative_number());
+}
+
+// https://www.w3.org/TR/SVG11/paths.html#PathDataBNF
+ErrorOr<float> AttributeParser::parse_nonnegative_number()
+{
+    // NOTE: The grammar is almost a floating point except we cannot have a sign
+    //       at the start. That condition should have been checked by the caller.
+    if (match('+') || match('-') || !match_number())
+        return Error::from_string_literal("Expected number");
+
+    auto remaining_source_text = m_lexer.remaining();
+    char const* start = remaining_source_text.characters_without_null_termination();
+
+    auto maybe_float = parse_first_floating_point<float>(start, start + remaining_source_text.length());
+    VERIFY(maybe_float.parsed_value());
+    m_lexer.ignore(maybe_float.end_ptr - start);
+
+    return maybe_float.value;
+}
+
+ErrorOr<float> AttributeParser::parse_flag()
+{
+    if (!match('0') && !match('1'))
+        return Error::from_string_literal("Expected flag");
+    return consume() - '0';
+}
+
+int AttributeParser::parse_sign()
+{
+    if (match('-')) {
+        consume();
+        return -1;
+    }
+    if (match('+'))
+        consume();
+    return 1;
+}
+
+static bool whitespace(char c)
+{
+    // wsp:
+    // Either a U+000A LINE FEED, U+000D CARRIAGE RETURN, U+0009 CHARACTER TABULATION, or U+0020 SPACE.
+    return AK::first_is_one_of(c, '\n', '\r', '\t', '\f', ' ');
+}
+
+// https://svgwg.org/svg2-draft/coords.html#PreserveAspectRatioAttribute
+Optional<PreserveAspectRatio> AttributeParser::parse_preserve_aspect_ratio(StringView input)
+{
+    // <align> <meetOrSlice>?
+    GenericLexer lexer { input };
+    lexer.ignore_while(whitespace);
+    auto align_string = lexer.consume_until(whitespace);
+    if (align_string.is_empty())
+        return {};
+    lexer.ignore_while(whitespace);
+    auto meet_or_slice_string = lexer.consume_until(whitespace);
+
+    // <align> =
+    //     none
+    //     | xMinYMin | xMidYMin | xMaxYMin
+    //     | xMinYMid | xMidYMid | xMaxYMid
+    //     | xMinYMax | xMidYMax | xMaxYMax
+    auto align = [&]() -> Optional<PreserveAspectRatio::Align> {
+        if (align_string == "none"sv)
+            return PreserveAspectRatio::Align::None;
+        if (align_string == "xMinYMin"sv)
+            return PreserveAspectRatio::Align::xMinYMin;
+        if (align_string == "xMidYMin"sv)
+            return PreserveAspectRatio::Align::xMidYMin;
+        if (align_string == "xMaxYMin"sv)
+            return PreserveAspectRatio::Align::xMaxYMin;
+        if (align_string == "xMinYMid"sv)
+            return PreserveAspectRatio::Align::xMinYMid;
+        if (align_string == "xMidYMid"sv)
+            return PreserveAspectRatio::Align::xMidYMid;
+        if (align_string == "xMaxYMid"sv)
+            return PreserveAspectRatio::Align::xMaxYMid;
+        if (align_string == "xMinYMax"sv)
+            return PreserveAspectRatio::Align::xMinYMax;
+        if (align_string == "xMidYMax"sv)
+            return PreserveAspectRatio::Align::xMidYMax;
+        if (align_string == "xMaxYMax"sv)
+            return PreserveAspectRatio::Align::xMaxYMax;
+        return {};
+    }();
+
+    if (!align.has_value())
+        return {};
+
+    // <meetOrSlice> = meet | slice
+    auto meet_or_slice = [&]() -> Optional<PreserveAspectRatio::MeetOrSlice> {
+        if (meet_or_slice_string.is_empty() || meet_or_slice_string == "meet"sv)
+            return PreserveAspectRatio::MeetOrSlice::Meet;
+        if (meet_or_slice_string == "slice"sv)
+            return PreserveAspectRatio::MeetOrSlice::Slice;
+        return {};
+    }();
+
+    if (!meet_or_slice.has_value())
+        return {};
+
+    return PreserveAspectRatio { *align, *meet_or_slice };
+}
+
+// https://svgwg.org/svg2-draft/pservers.html#LinearGradientElementGradientUnitsAttribute
+// https://drafts.fxtf.org/css-masking/#element-attrdef-mask-maskunits
+// https://drafts.fxtf.org/css-masking/#element-attrdef-mask-maskcontentunits
+Optional<SVGUnits> AttributeParser::parse_units(StringView input)
+{
+    GenericLexer lexer { input };
+    lexer.ignore_while(whitespace);
+    auto gradient_units_string = lexer.consume_until(whitespace);
+    if (gradient_units_string == "userSpaceOnUse"sv)
+        return SVGUnits::UserSpaceOnUse;
+    if (gradient_units_string == "objectBoundingBox"sv)
+        return SVGUnits::ObjectBoundingBox;
+    return {};
+}
+
+// https://svgwg.org/svg2-draft/pservers.html#RadialGradientElementSpreadMethodAttribute
+Optional<SpreadMethod> AttributeParser::parse_spread_method(StringView input)
+{
+    GenericLexer lexer { input };
+    lexer.ignore_while(whitespace);
+    auto spread_method_string = lexer.consume_until(whitespace);
+    if (spread_method_string == "pad"sv)
+        return SpreadMethod::Pad;
+    if (spread_method_string == "repeat"sv)
+        return SpreadMethod::Repeat;
+    if (spread_method_string == "reflect"sv)
+        return SpreadMethod::Reflect;
+    return {};
+}
+
+// https://drafts.csswg.org/css-transforms/#svg-syntax
+Optional<Vector<Transform>> AttributeParser::parse_transform()
+{
+    auto consume_whitespace = [&] {
+        m_lexer.ignore_while(whitespace);
+    };
+
+    auto consume_comma_whitespace = [&] {
+        consume_whitespace();
+        m_lexer.consume_specific(',');
+        consume_whitespace();
+    };
+
+    // FIXME: This parsing is quite lenient, so will accept (with default values) some transforms that should be rejected.
+    auto parse_optional_number = [&](float default_value = 0.0f) {
+        consume_comma_whitespace();
+        auto number_or_error = parse_number();
+        if (number_or_error.is_error())
+            return default_value;
+        return number_or_error.value();
+    };
+
+    auto try_parse_number = [&]() -> Optional<float> {
+        auto number_or_error = parse_number();
+        if (number_or_error.is_error())
+            return {};
+        return number_or_error.value();
+    };
+
+    auto parse_function = [&](auto body) -> Optional<Transform> {
+        consume_whitespace();
+        if (!m_lexer.consume_specific('('))
+            return {};
+        consume_whitespace();
+        auto maybe_operation = body();
+        if (!maybe_operation.has_value())
+            return {};
+        Transform transform { .operation = Transform::Operation { *maybe_operation } };
+        consume_whitespace();
+        if (m_lexer.consume_specific(')'))
+            return transform;
+        return {};
+    };
+
+    // NOTE: This looks very similar to the CSS transform but the syntax is not compatible.
+    Vector<Transform> transform_list;
+    consume_whitespace();
+    while (!done()) {
+        Optional<Transform> maybe_transform;
+        if (m_lexer.consume_specific("translate"sv)) {
+            maybe_transform = parse_function([&]() -> Optional<Transform::Translate> {
+                Transform::Translate translate {};
+                auto maybe_x = try_parse_number();
+                if (!maybe_x.has_value())
+                    return {};
+                translate.x = *maybe_x;
+                translate.y = parse_optional_number();
+                return translate;
+            });
+        } else if (m_lexer.consume_specific("scale"sv)) {
+            maybe_transform = parse_function([&]() -> Optional<Transform::Scale> {
+                Transform::Scale scale {};
+                auto maybe_x = try_parse_number();
+                if (!maybe_x.has_value())
+                    return {};
+                scale.x = *maybe_x;
+                scale.y = parse_optional_number(scale.x);
+                return scale;
+            });
+        } else if (m_lexer.consume_specific("rotate"sv)) {
+            maybe_transform = parse_function([&]() -> Optional<Transform::Rotate> {
+                Transform::Rotate rotate {};
+                auto maybe_a = try_parse_number();
+                if (!maybe_a.has_value())
+                    return {};
+                rotate.a = *maybe_a;
+                rotate.x = parse_optional_number();
+                rotate.y = parse_optional_number();
+                return rotate;
+            });
+        } else if (m_lexer.consume_specific("skewX"sv)) {
+            maybe_transform = parse_function([&]() -> Optional<Transform::SkewX> {
+                Transform::SkewX skew_x {};
+                auto maybe_a = try_parse_number();
+                if (!maybe_a.has_value())
+                    return {};
+                skew_x.a = *maybe_a;
+                return skew_x;
+            });
+        } else if (m_lexer.consume_specific("skewY"sv)) {
+            maybe_transform = parse_function([&]() -> Optional<Transform::SkewY> {
+                Transform::SkewY skew_y {};
+                auto maybe_a = try_parse_number();
+                if (!maybe_a.has_value())
+                    return {};
+                skew_y.a = *maybe_a;
+                return skew_y;
+            });
+        } else if (m_lexer.consume_specific("matrix"sv)) {
+            maybe_transform = parse_function([&]() -> Optional<Transform::Matrix> {
+                Transform::Matrix matrix;
+                auto maybe_a = try_parse_number();
+                if (!maybe_a.has_value())
+                    return {};
+                matrix.a = *maybe_a;
+                consume_comma_whitespace();
+                auto maybe_b = try_parse_number();
+                if (!maybe_b.has_value())
+                    return {};
+                matrix.b = *maybe_b;
+                consume_comma_whitespace();
+                auto maybe_c = try_parse_number();
+                if (!maybe_c.has_value())
+                    return {};
+                matrix.c = *maybe_c;
+                consume_comma_whitespace();
+                auto maybe_d = try_parse_number();
+                if (!maybe_d.has_value())
+                    return {};
+                matrix.d = *maybe_d;
+                consume_comma_whitespace();
+                auto maybe_e = try_parse_number();
+                if (!maybe_e.has_value())
+                    return {};
+                matrix.e = *maybe_e;
+                consume_comma_whitespace();
+                auto maybe_f = try_parse_number();
+                if (!maybe_f.has_value())
+                    return {};
+                matrix.f = *maybe_f;
+                return matrix;
+            });
+        }
+        if (maybe_transform.has_value())
+            transform_list.append(*maybe_transform);
+        else
+            return {};
+        consume_comma_whitespace();
+    }
+    return transform_list;
+}
+
+bool AttributeParser::match_whitespace() const
+{
+    if (done())
+        return false;
+    char c = ch();
+    return c == 0x9 || c == 0x20 || c == 0xa || c == 0xc || c == 0xd;
+}
+
+bool AttributeParser::match_comma_whitespace() const
+{
+    return match_whitespace() || match(',');
+}
+
+bool AttributeParser::match_coordinate() const
+{
+    return match_length();
+}
+
+bool AttributeParser::match_number() const
+{
+    return match_length();
+}
+
+bool AttributeParser::match_length() const
+{
+    if (done())
+        return false;
+
+    size_t offset = 0;
+    if (ch() == '-' || ch() == '+')
+        offset++;
+
+    if (ch(offset) == '.')
+        offset++;
+
+    return !done() && isdigit(ch(offset));
+}
+
+}