// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/strings/str_replace.h"
#include <cstddef>
#include <initializer_list>
#include <string>
#include <utility>
#include <vector>
#include "absl/base/config.h"
#include "absl/base/nullability.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace strings_internal {
using FixedMapping =
std::initializer_list<std::pair<absl::string_view, absl::string_view>>;
// Applies the ViableSubstitutions in subs_ptr to the absl::string_view s, and
// stores the result in *result_ptr. Returns the number of substitutions that
// occurred.
int ApplySubstitutions(
absl::string_view s,
absl::Nonnull<std::vector<strings_internal::ViableSubstitution>*> subs_ptr,
absl::Nonnull<std::string*> result_ptr) {
auto& subs = *subs_ptr;
int substitutions = 0;
size_t pos = 0;
while (!subs.empty()) {
auto& sub = subs.back();
if (sub.offset >= pos) {
if (pos <= s.size()) {
StrAppend(result_ptr, s.substr(pos, sub.offset - pos), sub.replacement);
}
pos = sub.offset + sub.old.size();
substitutions += 1;
}
sub.offset = s.find(sub.old, pos);
if (sub.offset == s.npos) {
subs.pop_back();
}
else {
// Insertion sort to ensure the last ViableSubstitution continues to be
// before all the others.
size_t index = subs.size();
while (--index && subs[index - 1].OccursBefore(subs[index])) {
std::swap(subs[index], subs[index - 1]);
}
}
}
result_ptr->append(s.data() + pos, s.size() - pos);
return substitutions;
}
}
// namespace strings_internal
// We can implement this in terms of the generic StrReplaceAll, but
// we must specify the template overload because C++ cannot deduce the type
// of an initializer_list parameter to a function, and also if we don't specify
// the type, we just call ourselves.
//
// Note that we implement them here, rather than in the header, so that they
// aren't inlined.
std::string StrReplaceAll(absl::string_view s,
strings_internal::FixedMapping replacements) {
return StrReplaceAll<strings_internal::FixedMapping>(s, replacements);
}
int StrReplaceAll(strings_internal::FixedMapping replacements,
absl::Nonnull<std::string*> target) {
return StrReplaceAll<strings_internal::FixedMapping>(replacements, target);
}
ABSL_NAMESPACE_END
}
// namespace absl
