[ADT] Fix a confusing interface spec and some annoying peculiarities

[oota-llvm.git] / lib / Support / StringRef.cpp

diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp
index f2e587cb527759b7e8fbbc27291f7f16228a24cd..88f920479dd2fefe7ca58547136fa239ce35ac31 100644 (file)
--- a/lib/Support/StringRef.cpp
+++ b/lib/Support/StringRef.cpp
@@ -274,44 +274,56 @@ StringRef::size_type StringRef::find_last_not_of(StringRef Chars,
 }
 
 void StringRef::split(SmallVectorImpl<StringRef> &A,
-                      StringRef Separators, int MaxSplit,
+                      StringRef Separator, int MaxSplit,
                       bool KeepEmpty) const {
-  StringRef rest = *this;
-
-  // rest.data() is used to distinguish cases like "a," that splits into
-  // "a" + "" and "a" that splits into "a" + 0.
-  for (int splits = 0;
-       rest.data() != nullptr && (MaxSplit < 0 || splits < MaxSplit);
-       ++splits) {
-    std::pair<StringRef, StringRef> p = rest.split(Separators);
-
-    if (KeepEmpty || p.first.size() != 0)
-      A.push_back(p.first);
-    rest = p.second;
+  StringRef S = *this;
+
+  // Count down from MaxSplit. When MaxSplit is -1, this will just split
+  // "forever". This doesn't support splitting more than 2^31 times
+  // intentionally; if we ever want that we can make MaxSplit a 64-bit integer
+  // but that seems unlikely to be useful.
+  while (MaxSplit-- != 0) {
+    size_t Idx = S.find(Separator);
+    if (Idx == npos)
+      break;
+
+    // Push this split.
+    if (KeepEmpty || Idx > 0)
+      A.push_back(S.slice(0, Idx));
+
+    // Jump forward.
+    S = S.slice(Idx + Separator.size(), npos);
   }
-  // If we have a tail left, add it.
-  if (rest.data() != nullptr && (rest.size() != 0 || KeepEmpty))
-    A.push_back(rest);
+
+  // Push the tail.
+  if (KeepEmpty || !S.empty())
+    A.push_back(S);
 }
 
 void StringRef::split(SmallVectorImpl<StringRef> &A, char Separator,
                       int MaxSplit, bool KeepEmpty) const {
-  StringRef rest = *this;
-
-  // rest.data() is used to distinguish cases like "a," that splits into
-  // "a" + "" and "a" that splits into "a" + 0.
-  for (int splits = 0;
-       rest.data() != nullptr && (MaxSplit < 0 || splits < MaxSplit);
-       ++splits) {
-    std::pair<StringRef, StringRef> p = rest.split(Separator);
-
-    if (KeepEmpty || p.first.size() != 0)
-      A.push_back(p.first);
-    rest = p.second;
+  StringRef S = *this;
+
+  // Count down from MaxSplit. When MaxSplit is -1, this will just split
+  // "forever". This doesn't support splitting more than 2^31 times
+  // intentionally; if we ever want that we can make MaxSplit a 64-bit integer
+  // but that seems unlikely to be useful.
+  while (MaxSplit-- != 0) {
+    size_t Idx = S.find(Separator);
+    if (Idx == npos)
+      break;
+
+    // Push this split.
+    if (KeepEmpty || Idx > 0)
+      A.push_back(S.slice(0, Idx));
+
+    // Jump forward.
+    S = S.slice(Idx + 1, npos);
   }
-  // If we have a tail left, add it.
-  if (rest.data() != nullptr && (rest.size() != 0 || KeepEmpty))
-    A.push_back(rest);
+
+  // Push the tail.
+  if (KeepEmpty || !S.empty())
+    A.push_back(S);
 }
 
 //===----------------------------------------------------------------------===//