summaryrefslogtreecommitdiff
path: root/absl/strings/str_replace.cc
diff options
context:
space:
mode:
authorGravatar misterg <misterg@google.com>2017-09-19 16:54:40 -0400
committerGravatar misterg <misterg@google.com>2017-09-19 16:54:40 -0400
commitc2e754829628d1e9b7a16b3389cfdace76950fdf (patch)
tree5a7f056f44e27c30e10025113b644f0b3b5801fc /absl/strings/str_replace.cc
Initial Commit
Diffstat (limited to 'absl/strings/str_replace.cc')
-rw-r--r--absl/strings/str_replace.cc79
1 files changed, 79 insertions, 0 deletions
diff --git a/absl/strings/str_replace.cc b/absl/strings/str_replace.cc
new file mode 100644
index 00000000..69efa357
--- /dev/null
+++ b/absl/strings/str_replace.cc
@@ -0,0 +1,79 @@
+// 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
+//
+// http://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 "absl/strings/str_cat.h"
+
+namespace absl {
+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,
+ std::vector<strings_internal::ViableSubstitution>* subs_ptr,
+ 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, std::string* target) {
+ return StrReplaceAll<strings_internal::FixedMapping>(replacements, target);
+}
+
+} // namespace absl