ADT/StringRef: Add ::lower() and ::upper() methods.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143880 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp
index 576b95f6a4..c78b6d0afc 100644
--- a/lib/Support/StringRef.cpp
+++ b/lib/Support/StringRef.cpp
@@ -25,6 +25,12 @@ static char ascii_tolower(char x) {
   return x;
 }
 
+static char ascii_toupper(char x) {
+  if (x >= 'a' && x <= 'z')
+    return x - 'a' + 'A';
+  return x;
+}
+
 static bool ascii_isdigit(char x) {
   return x >= '0' && x <= '9';
 }
@@ -132,6 +138,26 @@ unsigned StringRef::edit_distance(llvm::StringRef Other,
 }
 
 //===----------------------------------------------------------------------===//
+// String Operations
+//===----------------------------------------------------------------------===//
+
+std::string StringRef::lower() const {
+  std::string Result(size(), char());
+  for (size_type i = 0, e = size(); i != e; ++i) {
+    Result[i] = ascii_tolower(Data[i]);
+  }
+  return Result;
+}
+
+std::string StringRef::upper() const {
+  std::string Result(size(), char());
+  for (size_type i = 0, e = size(); i != e; ++i) {
+    Result[i] = ascii_tolower(Data[i]);
+  }
+  return Result;
+}
+
+//===----------------------------------------------------------------------===//
 // String Searching
 //===----------------------------------------------------------------------===//