Add StringRef::{rfind, rsplit}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82087 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 152 insertions, 44 deletions

diff --git a/include/llvm/ADT/StringRef.h b/include/llvm/ADT/StringRef.h
index acfc335..74d3eaa 100644
--- a/include/llvm/ADT/StringRef.h
+++ b/include/llvm/ADT/StringRef.h
@@ -147,7 +147,7 @@ namespace llvm {
     /// @name String Searching
     /// @{
 
-    /// find - Search for the character \arg C in the string.
+    /// find - Search for the first character \arg C in the string.
     ///
     /// \return - The index of the first occurence of \arg C, or npos if not
     /// found.
@@ -158,7 +158,7 @@ namespace llvm {
       return npos;
     }
 
-    /// find - Search for the string \arg Str in the string.
+    /// find - Search for the first string \arg Str in the string.
     ///
     /// \return - The index of the first occurence of \arg Str, or npos if not
     /// found.
@@ -172,6 +172,35 @@ namespace llvm {
       return npos;
     }
 
+    /// rfind - Search for the last character \arg C in the string.
+    ///
+    /// \return - The index of the last occurence of \arg C, or npos if not
+    /// found.
+    size_t rfind(char C) const {
+      for (size_t i = Length, e = 0; i != e;) {
+        --i;
+        if (Data[i] == C)
+          return i;
+      }
+      return npos;
+    }
+
+    /// rfind - Search for the last string \arg Str in the string.
+    ///
+    /// \return - The index of the last occurence of \arg Str, or npos if not
+    /// found.
+    size_t rfind(const StringRef &Str) const {
+      size_t N = Str.size();
+      if (N > Length)
+        return npos;
+      for (size_t i = Length - N + 1, e = 0; i != e;) {
+        --i;
+        if (substr(i, N).equals(Str))
+          return i;
+      }
+      return npos;
+    }
+
     /// count - Return the number of occurrences of \arg C in the string.
     size_t count(char C) const {
       size_t Count = 0;
@@ -245,6 +274,23 @@ namespace llvm {
       return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
     }
 
+    /// rsplit - Split into two substrings around the last occurence of a
+    /// separator character.
+    ///
+    /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
+    /// such that (*this == LHS + Separator + RHS) is true and RHS is
+    /// minimal. If \arg Separator is not in the string, then the result is a
+    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+    ///
+    /// \param Separator - The character to split on.
+    /// \return - The split substrings.
+    std::pair<StringRef, StringRef> rsplit(char Separator) const {
+      size_t Idx = rfind(Separator);
+      if (Idx == npos)
+        return std::make_pair(*this, StringRef());
+      return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
+    }
+
     /// @}
   };
 
diff --git a/lib/Support/CMakeLists.txt b/lib/Support/CMakeLists.txt
index 4f02397..cd355ff 100644
--- a/lib/Support/CMakeLists.txt
+++ b/lib/Support/CMakeLists.txt
@@ -27,6 +27,7 @@ add_llvm_library(LLVMSupport
   StringExtras.cpp
   StringMap.cpp
   StringPool.cpp
+  StringRef.cpp
   SystemUtils.cpp
   TargetRegistry.cpp
   Timer.cpp
diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp
new file mode 100644
index 0000000..4751f06
--- /dev/null
+++ b/lib/Support/StringRef.cpp
@@ -0,0 +1,13 @@
+//===-- StringRef.cpp - Lightweight String References ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/StringRef.h"
+using namespace llvm;
+
+const size_t StringRef::npos;
diff --git a/unittests/ADT/StringRefTest.cpp b/unittests/ADT/StringRefTest.cpp
index 320633a..cdc476e 100644
--- a/unittests/ADT/StringRefTest.cpp
+++ b/unittests/ADT/StringRefTest.cpp
@@ -14,18 +14,29 @@ using namespace llvm;
 
 namespace {
 
+std::ostream &operator<<(std::ostream &OS, const StringRef &S) {
+  OS << S;
+  return OS;
+}
+
+std::ostream &operator<<(std::ostream &OS,
+                         const std::pair<StringRef, StringRef> &P) {
+  OS << "(" << P.first << ", " << P.second << ")";
+  return OS;
+}
+
 TEST(StringRefTest, Construction) {
-  EXPECT_TRUE(StringRef() == "");
-  EXPECT_TRUE(StringRef("hello") == "hello");
-  EXPECT_TRUE(StringRef("hello world", 5) == "hello");
-  EXPECT_TRUE(StringRef(std::string("hello")) == "hello");
+  EXPECT_EQ("", StringRef());
+  EXPECT_EQ("hello", StringRef("hello"));
+  EXPECT_EQ("hello", StringRef("hello world", 5));
+  EXPECT_EQ("hello", StringRef(std::string("hello")));
 }
 
 TEST(StringRefTest, Iteration) {
   StringRef S("hello");
   const char *p = "hello";
   for (const char *it = S.begin(), *ie = S.end(); it != ie; ++it, ++p)
-    EXPECT_TRUE(*p == *it);
+    EXPECT_EQ(*it, *p);
 }
 
 TEST(StringRefTest, StringOps) {
@@ -41,7 +52,7 @@ TEST(StringRefTest, StringOps) {
 }
 
 TEST(StringRefTest, Operators) {
-  EXPECT_TRUE(StringRef() == "");
+  EXPECT_EQ("", StringRef());
   EXPECT_TRUE(StringRef("aab") < StringRef("aad"));
   EXPECT_FALSE(StringRef("aab") < StringRef("aab"));
   EXPECT_TRUE(StringRef("aab") <= StringRef("aab"));
@@ -50,58 +61,95 @@ TEST(StringRefTest, Operators) {
   EXPECT_FALSE(StringRef("aab") > StringRef("aab"));
   EXPECT_TRUE(StringRef("aab") >= StringRef("aab"));
   EXPECT_FALSE(StringRef("aaa") >= StringRef("aab"));
-  EXPECT_TRUE(StringRef("aab") == StringRef("aab"));
+  EXPECT_EQ(StringRef("aab"), StringRef("aab"));
   EXPECT_FALSE(StringRef("aab") == StringRef("aac"));
   EXPECT_FALSE(StringRef("aab") != StringRef("aab"));
   EXPECT_TRUE(StringRef("aab") != StringRef("aac"));
   EXPECT_EQ('a', StringRef("aab")[1]);
 }
 
-TEST(StringRefTest, Utilities) {
+TEST(StringRefTest, Substr) {
   StringRef Str("hello");
-  EXPECT_TRUE(Str.substr(3) == "lo");
-  EXPECT_TRUE(Str.substr(100) == "");
-  EXPECT_TRUE(Str.substr(0, 100) == "hello");
-  EXPECT_TRUE(Str.substr(4, 10) == "o");
-
-  EXPECT_TRUE(Str.slice(2, 3) == "l");
-  EXPECT_TRUE(Str.slice(1, 4) == "ell");
-  EXPECT_TRUE(Str.slice(2, 100) == "llo");
-  EXPECT_TRUE(Str.slice(2, 1) == "");
-  EXPECT_TRUE(Str.slice(10, 20) == "");
-
-  EXPECT_TRUE(Str.split('X') == std::make_pair(StringRef("hello"), 
-                                               StringRef("")));
-  EXPECT_TRUE(Str.split('e') == std::make_pair(StringRef("h"), 
-                                               StringRef("llo")));
-  EXPECT_TRUE(Str.split('h') == std::make_pair(StringRef(""), 
-                                               StringRef("ello")));
-  EXPECT_TRUE(Str.split('o') == std::make_pair(StringRef("hell"), 
-                                               StringRef("")));
+  EXPECT_EQ("lo", Str.substr(3));
+  EXPECT_EQ("", Str.substr(100));
+  EXPECT_EQ("hello", Str.substr(0, 100));
+  EXPECT_EQ("o", Str.substr(4, 10));
+}
+
+TEST(StringRefTest, Slice) {
+  StringRef Str("hello");
+  EXPECT_EQ("l", Str.slice(2, 3));
+  EXPECT_EQ("ell", Str.slice(1, 4));
+  EXPECT_EQ("llo", Str.slice(2, 100));
+  EXPECT_EQ("", Str.slice(2, 1));
+  EXPECT_EQ("", Str.slice(10, 20));
+}
+
+TEST(StringRefTest, Split) {
+  StringRef Str("hello");
+  EXPECT_EQ(std::make_pair(StringRef("hello"), StringRef("")),
+            Str.split('X'));
+  EXPECT_EQ(std::make_pair(StringRef("h"), StringRef("llo")),
+            Str.split('e'));
+  EXPECT_EQ(std::make_pair(StringRef(""), StringRef("ello")),
+            Str.split('h'));
+  EXPECT_EQ(std::make_pair(StringRef("he"), StringRef("lo")),
+            Str.split('l'));
+  EXPECT_EQ(std::make_pair(StringRef("hell"), StringRef("")),
+            Str.split('o'));
+
+  EXPECT_EQ(std::make_pair(StringRef("hello"), StringRef("")),
+            Str.rsplit('X'));
+  EXPECT_EQ(std::make_pair(StringRef("h"), StringRef("llo")),
+            Str.rsplit('e'));
+  EXPECT_EQ(std::make_pair(StringRef(""), StringRef("ello")),
+            Str.rsplit('h'));
+  EXPECT_EQ(std::make_pair(StringRef("hel"), StringRef("o")),
+            Str.rsplit('l'));
+  EXPECT_EQ(std::make_pair(StringRef("hell"), StringRef("")),
+            Str.rsplit('o'));
+}
 
+TEST(StringRefTest, StartsWith) {
+  StringRef Str("hello");
   EXPECT_TRUE(Str.startswith("he"));
   EXPECT_FALSE(Str.startswith("helloworld"));
   EXPECT_FALSE(Str.startswith("hi"));
+}
 
+TEST(StringRefTest, Find) {
+  StringRef Str("hello");
+  EXPECT_EQ(2U, Str.find('l'));
+  EXPECT_EQ(StringRef::npos, Str.find('z'));
+  EXPECT_EQ(StringRef::npos, Str.find("helloworld"));
+  EXPECT_EQ(0U, Str.find("hello"));
+  EXPECT_EQ(1U, Str.find("ello"));
+  EXPECT_EQ(StringRef::npos, Str.find("zz"));
+
+  EXPECT_EQ(3U, Str.rfind('l'));
+  EXPECT_EQ(StringRef::npos, Str.rfind('z'));
+  EXPECT_EQ(StringRef::npos, Str.rfind("helloworld"));
+  EXPECT_EQ(0U, Str.rfind("hello"));
+  EXPECT_EQ(1U, Str.rfind("ello"));
+  EXPECT_EQ(StringRef::npos, Str.rfind("zz"));
+}
+
+TEST(StringRefTest, Count) {
+  StringRef Str("hello");
+  EXPECT_EQ(2U, Str.count('l'));
+  EXPECT_EQ(1U, Str.count('o'));
+  EXPECT_EQ(0U, Str.count('z'));
+  EXPECT_EQ(0U, Str.count("helloworld"));
+  EXPECT_EQ(1U, Str.count("hello"));
+  EXPECT_EQ(1U, Str.count("ello"));
+  EXPECT_EQ(0U, Str.count("zz"));
+}
+
+TEST(StringRefTest, Misc) {
   std::string Storage;
   raw_string_ostream OS(Storage);
   OS << StringRef("hello");
   EXPECT_EQ("hello", OS.str());
-
-  EXPECT_TRUE(Str.find('l') == 2);
-  EXPECT_TRUE(Str.find('z') == StringRef::npos);
-  EXPECT_TRUE(Str.find("helloworld") == StringRef::npos);
-  EXPECT_TRUE(Str.find("hello") == 0);
-  EXPECT_TRUE(Str.find("ello") == 1);
-  EXPECT_TRUE(Str.find("zz") == StringRef::npos);
-
-  EXPECT_TRUE(Str.count('l') == 2);
-  EXPECT_TRUE(Str.count('o') == 1);
-  EXPECT_TRUE(Str.count('z') == 0);
-  EXPECT_TRUE(Str.count("helloworld") == 0);
-  EXPECT_TRUE(Str.count("hello") == 1);
-  EXPECT_TRUE(Str.count("ello") == 1);
-  EXPECT_TRUE(Str.count("zz") == 0);
 }
 
 } // end anonymous namespace