ladybird/Userland/Libraries/LibWeb/Infra/Strings.cpp
Timothy Flynn 1edb96376b AK+Everywhere: Make UTF-8 and UTF-32 to UTF-16 converters fallible
These could fail to allocate the underlying storage needed to store the
UTF-16 data. Propagate these errors.
2023-01-08 12:13:15 +01:00

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/*
* Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
* Copyright (c) 2022, networkException <networkexception@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/DeprecatedString.h>
#include <AK/Utf16View.h>
#include <AK/Utf8View.h>
#include <LibWeb/Infra/CharacterTypes.h>
#include <LibWeb/Infra/Strings.h>
namespace Web::Infra {
// https://infra.spec.whatwg.org/#strip-and-collapse-ascii-whitespace
DeprecatedString strip_and_collapse_whitespace(StringView string)
{
// Replace any sequence of one or more consecutive code points that are ASCII whitespace in the string with a single U+0020 SPACE code point.
StringBuilder builder;
for (auto code_point : Utf8View { string }) {
if (Infra::is_ascii_whitespace(code_point)) {
if (!builder.string_view().ends_with(' '))
builder.append(' ');
continue;
}
builder.append_code_point(code_point);
}
// ...and then remove any leading and trailing ASCII whitespace from that string.
return builder.string_view().trim(Infra::ASCII_WHITESPACE);
}
// https://infra.spec.whatwg.org/#code-unit-prefix
bool is_code_unit_prefix(StringView potential_prefix, StringView input)
{
auto potential_prefix_utf16 = utf8_to_utf16(potential_prefix).release_value_but_fixme_should_propagate_errors();
auto input_utf16 = utf8_to_utf16(input).release_value_but_fixme_should_propagate_errors();
// 1. Let i be 0.
size_t i = 0;
// 2. While true:
while (true) {
// 1. If i is greater than or equal to potentialPrefixs length, then return true.
if (i >= potential_prefix.length())
return true;
// 2. If i is greater than or equal to inputs length, then return false.
if (i >= input.length())
return false;
// 3. Let potentialPrefixCodeUnit be the ith code unit of potentialPrefix.
auto potential_prefix_code_unit = Utf16View(potential_prefix_utf16).code_unit_at(i);
// 4. Let inputCodeUnit be the ith code unit of input.
auto input_code_unit = Utf16View(input_utf16).code_unit_at(i);
// 5. Return false if potentialPrefixCodeUnit is not inputCodeUnit.
if (potential_prefix_code_unit != input_code_unit)
return false;
// 6. Set i to i + 1.
++i;
}
}
}