folly refactorings to better support cross-platform

[folly.git] / folly / StringBase.cpp

diff --git a/folly/StringBase.cpp b/folly/StringBase.cpp
new file mode 100644 (file)
index 0000000..6c428d6
--- /dev/null
+++ b/folly/StringBase.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2015 Facebook, Inc.
+ *
+ * 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 <folly/String.h>
+
+namespace folly {
+
+StringPiece skipWhitespace(StringPiece sp) {
+  // Spaces other than ' ' characters are less common but should be
+  // checked.  This configuration where we loop on the ' '
+  // separately from oddspaces was empirically fastest.
+  auto oddspace = [] (char c) {
+    return c == '\n' || c == '\t' || c == '\r';
+  };
+
+loop:
+  for (; !sp.empty() && sp.front() == ' '; sp.pop_front()) {
+  }
+  if (!sp.empty() && oddspace(sp.front())) {
+    sp.pop_front();
+    goto loop;
+  }
+
+  return sp;
+}
+
+}