diff -r 000000000000 -r 6474c204b198 xpcom/ds/nsWhitespaceTokenizer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/ds/nsWhitespaceTokenizer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,165 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __nsWhitespaceTokenizer_h
+#define __nsWhitespaceTokenizer_h
+
+#include "mozilla/RangedPtr.h"
+#include "nsDependentSubstring.h"
+#include "nsCRT.h"
+
+template<bool IsWhitespace(char16_t) = NS_IsAsciiWhitespace>
+class nsWhitespaceTokenizerTemplate
+{
+public:
+    nsWhitespaceTokenizerTemplate(const nsSubstring& aSource)
+        : mIter(aSource.Data(), aSource.Length()),
+          mEnd(aSource.Data() + aSource.Length(), aSource.Data(),
+               aSource.Length()),
+          mWhitespaceBeforeFirstToken(false),
+          mWhitespaceAfterCurrentToken(false)
+    {
+        while (mIter < mEnd && IsWhitespace(*mIter)) {
+            mWhitespaceBeforeFirstToken = true;
+            ++mIter;
+        }
+    }
+
+    /**
+     * Checks if any more tokens are available.
+     */
+    bool hasMoreTokens() const
+    {
+        return mIter < mEnd;
+    }
+
+    /*
+     * Returns true if there is whitespace prior to the first token.
+     */
+    bool whitespaceBeforeFirstToken() const
+    {
+        return mWhitespaceBeforeFirstToken;
+    }
+
+    /*
+     * Returns true if there is any whitespace after the current token.
+     * This is always true unless we're reading the last token.
+     */
+    bool whitespaceAfterCurrentToken() const
+    {
+        return mWhitespaceAfterCurrentToken;
+    }
+
+    /**
+     * Returns the next token.
+     */
+    const nsDependentSubstring nextToken()
+    {
+        const mozilla::RangedPtr<const char16_t> tokenStart = mIter;
+        while (mIter < mEnd && !IsWhitespace(*mIter)) {
+            ++mIter;
+        }
+        const mozilla::RangedPtr<const char16_t> tokenEnd = mIter;
+        mWhitespaceAfterCurrentToken = false;
+        while (mIter < mEnd && IsWhitespace(*mIter)) {
+            mWhitespaceAfterCurrentToken = true;
+            ++mIter;
+        }
+        return Substring(tokenStart.get(), tokenEnd.get());
+    }
+
+private:
+    mozilla::RangedPtr<const char16_t> mIter;
+    const mozilla::RangedPtr<const char16_t> mEnd;
+    bool mWhitespaceBeforeFirstToken;
+    bool mWhitespaceAfterCurrentToken;
+};
+
+class nsWhitespaceTokenizer: public nsWhitespaceTokenizerTemplate<>
+{
+public:
+    nsWhitespaceTokenizer(const nsSubstring& aSource)
+      : nsWhitespaceTokenizerTemplate<>(aSource)
+    {
+    }
+};
+
+template<bool IsWhitespace(char16_t) = NS_IsAsciiWhitespace>
+class nsCWhitespaceTokenizerTemplate
+{
+public:
+    nsCWhitespaceTokenizerTemplate(const nsCSubstring& aSource)
+        : mIter(aSource.Data(), aSource.Length()),
+          mEnd(aSource.Data() + aSource.Length(), aSource.Data(),
+               aSource.Length()),
+          mWhitespaceBeforeFirstToken(false),
+          mWhitespaceAfterCurrentToken(false)
+    {
+        while (mIter < mEnd && IsWhitespace(*mIter)) {
+            mWhitespaceBeforeFirstToken = true;
+            ++mIter;
+        }
+    }
+
+    /**
+     * Checks if any more tokens are available.
+     */
+    bool hasMoreTokens() const
+    {
+        return mIter < mEnd;
+    }
+
+    /*
+     * Returns true if there is whitespace prior to the first token.
+     */
+    bool whitespaceBeforeFirstToken() const
+    {
+        return mWhitespaceBeforeFirstToken;
+    }
+
+    /*
+     * Returns true if there is any whitespace after the current token.
+     * This is always true unless we're reading the last token.
+     */
+    bool whitespaceAfterCurrentToken() const
+    {
+        return mWhitespaceAfterCurrentToken;
+    }
+
+    /**
+     * Returns the next token.
+     */
+    const nsDependentCSubstring nextToken()
+    {
+        const mozilla::RangedPtr<const char> tokenStart = mIter;
+        while (mIter < mEnd && !IsWhitespace(*mIter)) {
+            ++mIter;
+        }
+        const mozilla::RangedPtr<const char> tokenEnd = mIter;
+        mWhitespaceAfterCurrentToken = false;
+        while (mIter < mEnd && IsWhitespace(*mIter)) {
+            mWhitespaceAfterCurrentToken = true;
+            ++mIter;
+        }
+        return Substring(tokenStart.get(), tokenEnd.get());
+    }
+
+private:
+    mozilla::RangedPtr<const char> mIter;
+    const mozilla::RangedPtr<const char> mEnd;
+    bool mWhitespaceBeforeFirstToken;
+    bool mWhitespaceAfterCurrentToken;
+};
+
+class nsCWhitespaceTokenizer: public nsCWhitespaceTokenizerTemplate<>
+{
+public:
+    nsCWhitespaceTokenizer(const nsCSubstring& aSource)
+      : nsCWhitespaceTokenizerTemplate<>(aSource)
+    {
+    }
+};
+
+#endif /* __nsWhitespaceTokenizer_h */