Meta: Replace GenerateCSSPseudoClass with a python generator

Author: https://github.com/AtkinsSJ
Commit: https://github.com/LadybirdBrowser/ladybird/commit/91022151d65
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/9083

Meta/Generators/generate_libweb_css_pseudo_class.py

@@ -0,0 +1,191 @@
+#!/usr/bin/env python3
+
+# Copyright (c) 2022-2026, Sam Atkins <sam@ladybird.org>
+# Copyright (c) 2026-present, the Ladybird developers.
+#
+# SPDX-License-Identifier: BSD-2-Clause
+
+import argparse
+import json
+import sys
+
+from pathlib import Path
+from typing import TextIO
+
+sys.path.append(str(Path(__file__).resolve().parent.parent))
+
+from Utils.utils import title_casify
+
+PARAMETER_TYPES = {
+    "<an+b>": "ANPlusB",
+    "<an+b-of>": "ANPlusBOf",
+    "<compound-selector>": "CompoundSelector",
+    "<forgiving-selector-list>": "ForgivingSelectorList",
+    "<forgiving-relative-selector-list>": "ForgivingRelativeSelectorList",
+    "<ident>": "Ident",
+    "<language-ranges>": "LanguageRanges",
+    "<level>#": "LevelList",
+    "<relative-selector-list>": "RelativeSelectorList",
+    "<selector-list>": "SelectorList",
+}
+
+
+def write_header_file(out: TextIO, pseudo_classes_data: dict) -> None:
+    out.write("""
+#pragma once
+
+#include <AK/Optional.h>
+#include <AK/StringView.h>
+
+namespace Web::CSS {
+
+enum class PseudoClass {
+""")
+
+    for name, value in pseudo_classes_data.items():
+        if "legacy-alias-for" in value:
+            continue
+        out.write(f"    {title_casify(name)},\n")
+
+    out.write("""
+    __Count,
+};
+
+Optional<PseudoClass> pseudo_class_from_string(StringView);
+StringView pseudo_class_name(PseudoClass);
+
+struct PseudoClassMetadata {
+    enum class ParameterType {
+        None,
+        ANPlusB,
+        ANPlusBOf,
+        CompoundSelector,
+        ForgivingSelectorList,
+        ForgivingRelativeSelectorList,
+        Ident,
+        LanguageRanges,
+        LevelList,
+        RelativeSelectorList,
+        SelectorList,
+    } parameter_type;
+    bool is_valid_as_function;
+    bool is_valid_as_identifier;
+};
+PseudoClassMetadata pseudo_class_metadata(PseudoClass);
+
+}
+""")
+
+
+def write_implementation_file(out: TextIO, pseudo_classes_data: dict) -> None:
+    out.write("""
+#include <LibWeb/CSS/PseudoClass.h>
+
+namespace Web::CSS {
+
+Optional<PseudoClass> pseudo_class_from_string(StringView string)
+{
+""")
+
+    for name, value in pseudo_classes_data.items():
+        alias_for = value.get("legacy-alias-for")
+        target_name = title_casify(alias_for) if alias_for is not None else title_casify(name)
+        out.write(f"""
+    if (string.equals_ignoring_ascii_case("{name}"sv))
+        return PseudoClass::{target_name};
+""")
+
+    out.write("""
+
+    return {};
+}
+
+StringView pseudo_class_name(PseudoClass pseudo_class)
+{
+    switch (pseudo_class) {
+    case PseudoClass::__Count:
+        VERIFY_NOT_REACHED();
+""")
+
+    for name, value in pseudo_classes_data.items():
+        if "legacy-alias-for" in value:
+            continue
+        out.write(f"""
+    case PseudoClass::{title_casify(name)}:
+        return "{name}"sv;
+""")
+
+    out.write("""
+    }
+    VERIFY_NOT_REACHED();
+}
+
+PseudoClassMetadata pseudo_class_metadata(PseudoClass pseudo_class)
+{
+    switch (pseudo_class) {
+    case PseudoClass::__Count:
+        VERIFY_NOT_REACHED();
+""")
+
+    for name, value in pseudo_classes_data.items():
+        if "legacy-alias-for" in value:
+            continue
+
+        argument_string = value["argument"]
+        is_valid_as_identifier = argument_string == ""
+        is_valid_as_function = argument_string != ""
+
+        if argument_string.endswith("?"):
+            is_valid_as_identifier = True
+            argument_string = argument_string[:-1]
+
+        parameter_type = "None"
+        if is_valid_as_function:
+            if argument_string not in PARAMETER_TYPES:
+                print(f"Unrecognized pseudo-class argument type: `{argument_string}`", file=sys.stderr)
+                sys.exit(1)
+            parameter_type = PARAMETER_TYPES[argument_string]
+
+        is_valid_as_function_str = "true" if is_valid_as_function else "false"
+        is_valid_as_identifier_str = "true" if is_valid_as_identifier else "false"
+
+        out.write(f"""
+    case PseudoClass::{title_casify(name)}:
+        return {{
+            .parameter_type = PseudoClassMetadata::ParameterType::{parameter_type},
+            .is_valid_as_function = {is_valid_as_function_str},
+            .is_valid_as_identifier = {is_valid_as_identifier_str},
+        }};
+""")
+
+    out.write("""
+    }
+    VERIFY_NOT_REACHED();
+}
+
+}
+""")
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Generate CSS PseudoClasses", add_help=False)
+    parser.add_argument("--help", action="help", help="Show this help message and exit")
+    parser.add_argument("-h", "--header", required=True, help="Path to the PseudoClasses header file to generate")
+    parser.add_argument(
+        "-c", "--implementation", required=True, help="Path to the PseudoClasses implementation file to generate"
+    )
+    parser.add_argument("-j", "--json", required=True, help="Path to the JSON file to read from")
+    args = parser.parse_args()
+
+    with open(args.json, "r", encoding="utf-8") as input_file:
+        pseudo_classes_data = json.load(input_file)
+
+    with open(args.header, "w", encoding="utf-8") as output_file:
+        write_header_file(output_file, pseudo_classes_data)
+
+    with open(args.implementation, "w", encoding="utf-8") as output_file:
+        write_implementation_file(output_file, pseudo_classes_data)
+
+
+if __name__ == "__main__":
+    main()