/* * Copyright (c) 2024-2025, Sam Atkins * * SPDX-License-Identifier: BSD-2-Clause */ #pragma once #include #include namespace Web::CSS { inline bool is_invalid_custom_property_name_string(StringView string) { // https://drafts.csswg.org/css-variables-2/#typedef-custom-property-name // The production corresponds to this: it’s defined as any // (a valid identifier that starts with two dashes), except -- itself, which is reserved for future use by CSS. return string == "--"sv; } // https://drafts.css-houdini.org/css-typed-om-1/#custom-property-name-string inline bool is_a_custom_property_name_string(StringView string) { // A string is a custom property name string if it starts with two dashes (U+002D HYPHEN-MINUS), like --foo. return string.starts_with("--"sv) && !is_invalid_custom_property_name_string(string); } // https://drafts.css-houdini.org/css-typed-om-1/#valid-css-property inline bool is_a_valid_css_property(StringView string) { // A string is a valid CSS property if it is a custom property name string, or is a CSS property name recognized by // the user agent. return is_a_custom_property_name_string(string) || property_id_from_string(string).has_value(); } }