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diff --git a/guava/src/com/google/common/base/Splitter.java b/guava/src/com/google/common/base/Splitter.java
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+++ b/guava/src/com/google/common/base/Splitter.java
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+/*
+ * Copyright (C) 2009 The Guava Authors
+ *
+ * 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.
+ */
+
+package com.google.common.base;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.annotations.Beta;
+import com.google.common.annotations.GwtCompatible;
+import com.google.common.annotations.GwtIncompatible;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.annotation.CheckReturnValue;
+
+/**
+ * An object that divides strings (or other instances of {@code CharSequence})
+ * into substrings, by recognizing a <i>separator</i> (a.k.a. "delimiter")
+ * which can be expressed as a single character, literal string, regular
+ * expression, {@code CharMatcher}, or by using a fixed substring length. This
+ * class provides the complementary functionality to {@link Joiner}.
+ *
+ * <p>Here is the most basic example of {@code Splitter} usage: <pre>   {@code
+ *
+ *   Splitter.on(',').split("foo,bar")}</pre>
+ *
+ * This invocation returns an {@code Iterable<String>} containing {@code "foo"}
+ * and {@code "bar"}, in that order.
+ *
+ * <p>By default {@code Splitter}'s behavior is very simplistic: <pre>   {@code
+ *
+ *   Splitter.on(',').split("foo,,bar, quux")}</pre>
+ *
+ * This returns an iterable containing {@code ["foo", "", "bar", " quux"]}.
+ * Notice that the splitter does not assume that you want empty strings removed,
+ * or that you wish to trim whitespace. If you want features like these, simply
+ * ask for them: <pre> {@code
+ *
+ *   private static final Splitter MY_SPLITTER = Splitter.on(',')
+ *       .trimResults()
+ *       .omitEmptyStrings();}</pre>
+ *
+ * Now {@code MY_SPLITTER.split("foo, ,bar, quux,")} returns an iterable
+ * containing just {@code ["foo", "bar", "quux"]}. Note that the order in which
+ * the configuration methods are called is never significant; for instance,
+ * trimming is always applied first before checking for an empty result,
+ * regardless of the order in which the {@link #trimResults()} and
+ * {@link #omitEmptyStrings()} methods were invoked.
+ *
+ * <p><b>Warning: splitter instances are always immutable</b>; a configuration
+ * method such as {@code omitEmptyStrings} has no effect on the instance it
+ * is invoked on! You must store and use the new splitter instance returned by
+ * the method. This makes splitters thread-safe, and safe to store as {@code
+ * static final} constants (as illustrated above). <pre>   {@code
+ *
+ *   // Bad! Do not do this!
+ *   Splitter splitter = Splitter.on('/');
+ *   splitter.trimResults(); // does nothing!
+ *   return splitter.split("wrong / wrong / wrong");}</pre>
+ *
+ * The separator recognized by the splitter does not have to be a single
+ * literal character as in the examples above. See the methods {@link
+ * #on(String)}, {@link #on(Pattern)} and {@link #on(CharMatcher)} for examples
+ * of other ways to specify separators.
+ *
+ * <p><b>Note:</b> this class does not mimic any of the quirky behaviors of
+ * similar JDK methods; for instance, it does not silently discard trailing
+ * separators, as does {@link String#split(String)}, nor does it have a default
+ * behavior of using five particular whitespace characters as separators, like
+ * {@link java.util.StringTokenizer}.
+ *
+ * <p>See the Guava User Guide article on <a href=
+ * "http://code.google.com/p/guava-libraries/wiki/StringsExplained#Splitter">
+ * {@code Splitter}</a>.
+ *
+ * @author Julien Silland
+ * @author Jesse Wilson
+ * @author Kevin Bourrillion
+ * @author Louis Wasserman
+ * @since 1.0
+ */
+@GwtCompatible(emulated = true)
+public final class Splitter {
+  private final CharMatcher trimmer;
+  private final boolean omitEmptyStrings;
+  private final Strategy strategy;
+  private final int limit;
+
+  private Splitter(Strategy strategy) {
+    this(strategy, false, CharMatcher.NONE, Integer.MAX_VALUE);
+  }
+
+  private Splitter(Strategy strategy, boolean omitEmptyStrings,
+      CharMatcher trimmer, int limit) {
+    this.strategy = strategy;
+    this.omitEmptyStrings = omitEmptyStrings;
+    this.trimmer = trimmer;
+    this.limit = limit;
+  }
+
+  /**
+   * Returns a splitter that uses the given single-character separator. For
+   * example, {@code Splitter.on(',').split("foo,,bar")} returns an iterable
+   * containing {@code ["foo", "", "bar"]}.
+   *
+   * @param separator the character to recognize as a separator
+   * @return a splitter, with default settings, that recognizes that separator
+   */
+  public static Splitter on(char separator) {
+    return on(CharMatcher.is(separator));
+  }
+
+  /**
+   * Returns a splitter that considers any single character matched by the
+   * given {@code CharMatcher} to be a separator. For example, {@code
+   * Splitter.on(CharMatcher.anyOf(";,")).split("foo,;bar,quux")} returns an
+   * iterable containing {@code ["foo", "", "bar", "quux"]}.
+   *
+   * @param separatorMatcher a {@link CharMatcher} that determines whether a
+   *     character is a separator
+   * @return a splitter, with default settings, that uses this matcher
+   */
+  public static Splitter on(final CharMatcher separatorMatcher) {
+    checkNotNull(separatorMatcher);
+
+    return new Splitter(new Strategy() {
+      @Override public SplittingIterator iterator(
+          Splitter splitter, final CharSequence toSplit) {
+        return new SplittingIterator(splitter, toSplit) {
+          @Override int separatorStart(int start) {
+            return separatorMatcher.indexIn(toSplit, start);
+          }
+
+          @Override int separatorEnd(int separatorPosition) {
+            return separatorPosition + 1;
+          }
+        };
+      }
+    });
+  }
+
+  /**
+   * Returns a splitter that uses the given fixed string as a separator. For
+   * example, {@code Splitter.on(", ").split("foo, bar, baz,qux")} returns an
+   * iterable containing {@code ["foo", "bar", "baz,qux"]}.
+   *
+   * @param separator the literal, nonempty string to recognize as a separator
+   * @return a splitter, with default settings, that recognizes that separator
+   */
+  public static Splitter on(final String separator) {
+    checkArgument(separator.length() != 0,
+        "The separator may not be the empty string.");
+
+    return new Splitter(new Strategy() {
+      @Override public SplittingIterator iterator(
+          Splitter splitter, CharSequence toSplit) {
+        return new SplittingIterator(splitter, toSplit) {
+          @Override public int separatorStart(int start) {
+            int delimeterLength = separator.length();
+
+            positions:
+            for (int p = start, last = toSplit.length() - delimeterLength;
+                p <= last; p++) {
+              for (int i = 0; i < delimeterLength; i++) {
+                if (toSplit.charAt(i + p) != separator.charAt(i)) {
+                  continue positions;
+                }
+              }
+              return p;
+            }
+            return -1;
+          }
+
+          @Override public int separatorEnd(int separatorPosition) {
+            return separatorPosition + separator.length();
+          }
+        };
+      }
+    });
+  }
+
+  /**
+   * Returns a splitter that considers any subsequence matching {@code
+   * pattern} to be a separator. For example, {@code
+   * Splitter.on(Pattern.compile("\r?\n")).split(entireFile)} splits a string
+   * into lines whether it uses DOS-style or UNIX-style line terminators.
+   *
+   * @param separatorPattern the pattern that determines whether a subsequence
+   *     is a separator. This pattern may not match the empty string.
+   * @return a splitter, with default settings, that uses this pattern
+   * @throws IllegalArgumentException if {@code separatorPattern} matches the
+   *     empty string
+   */
+  @GwtIncompatible("java.util.regex")
+  public static Splitter on(final Pattern separatorPattern) {
+    checkNotNull(separatorPattern);
+    checkArgument(!separatorPattern.matcher("").matches(),
+        "The pattern may not match the empty string: %s", separatorPattern);
+
+    return new Splitter(new Strategy() {
+      @Override public SplittingIterator iterator(
+          final Splitter splitter, CharSequence toSplit) {
+        final Matcher matcher = separatorPattern.matcher(toSplit);
+        return new SplittingIterator(splitter, toSplit) {
+          @Override public int separatorStart(int start) {
+            return matcher.find(start) ? matcher.start() : -1;
+          }
+
+          @Override public int separatorEnd(int separatorPosition) {
+            return matcher.end();
+          }
+        };
+      }
+    });
+  }
+
+  /**
+   * Returns a splitter that considers any subsequence matching a given
+   * pattern (regular expression) to be a separator. For example, {@code
+   * Splitter.onPattern("\r?\n").split(entireFile)} splits a string into lines
+   * whether it uses DOS-style or UNIX-style line terminators. This is
+   * equivalent to {@code Splitter.on(Pattern.compile(pattern))}.
+   *
+   * @param separatorPattern the pattern that determines whether a subsequence
+   *     is a separator. This pattern may not match the empty string.
+   * @return a splitter, with default settings, that uses this pattern
+   * @throws java.util.regex.PatternSyntaxException if {@code separatorPattern}
+   *     is a malformed expression
+   * @throws IllegalArgumentException if {@code separatorPattern} matches the
+   *     empty string
+   */
+  @GwtIncompatible("java.util.regex")
+  public static Splitter onPattern(String separatorPattern) {
+    return on(Pattern.compile(separatorPattern));
+  }
+
+  /**
+   * Returns a splitter that divides strings into pieces of the given length.
+   * For example, {@code Splitter.fixedLength(2).split("abcde")} returns an
+   * iterable containing {@code ["ab", "cd", "e"]}. The last piece can be
+   * smaller than {@code length} but will never be empty.
+   *
+   * @param length the desired length of pieces after splitting
+   * @return a splitter, with default settings, that can split into fixed sized
+   *     pieces
+   */
+  public static Splitter fixedLength(final int length) {
+    checkArgument(length > 0, "The length may not be less than 1");
+
+    return new Splitter(new Strategy() {
+      @Override public SplittingIterator iterator(
+          final Splitter splitter, CharSequence toSplit) {
+        return new SplittingIterator(splitter, toSplit) {
+          @Override public int separatorStart(int start) {
+            int nextChunkStart = start + length;
+            return (nextChunkStart < toSplit.length() ? nextChunkStart : -1);
+          }
+
+          @Override public int separatorEnd(int separatorPosition) {
+            return separatorPosition;
+          }
+        };
+      }
+    });
+  }
+
+  /**
+   * Returns a splitter that behaves equivalently to {@code this} splitter, but
+   * automatically omits empty strings from the results. For example, {@code
+   * Splitter.on(',').omitEmptyStrings().split(",a,,,b,c,,")} returns an
+   * iterable containing only {@code ["a", "b", "c"]}.
+   *
+   * <p>If either {@code trimResults} option is also specified when creating a
+   * splitter, that splitter always trims results first before checking for
+   * emptiness. So, for example, {@code
+   * Splitter.on(':').omitEmptyStrings().trimResults().split(": : : ")} returns
+   * an empty iterable.
+   *
+   * <p>Note that it is ordinarily not possible for {@link #split(CharSequence)}
+   * to return an empty iterable, but when using this option, it can (if the
+   * input sequence consists of nothing but separators).
+   *
+   * @return a splitter with the desired configuration
+   */
+  @CheckReturnValue
+  public Splitter omitEmptyStrings() {
+    return new Splitter(strategy, true, trimmer, limit);
+  }
+
+  /**
+   * Returns a splitter that behaves equivalently to {@code this} splitter but
+   * stops splitting after it reaches the limit.
+   * The limit defines the maximum number of items returned by the iterator.
+   *
+   * <p>For example,
+   * {@code Splitter.on(',').limit(3).split("a,b,c,d")} returns an iterable
+   * containing {@code ["a", "b", "c,d"]}.  When omitting empty strings, the
+   * omitted strings do no count.  Hence,
+   * {@code Splitter.on(',').limit(3).omitEmptyStrings().split("a,,,b,,,c,d")}
+   * returns an iterable containing {@code ["a", "b", "c,d"}.
+   * When trim is requested, all entries, including the last are trimmed.  Hence
+   * {@code Splitter.on(',').limit(3).trimResults().split(" a , b , c , d ")}
+   * results in @{code ["a", "b", "c , d"]}.
+   *
+   * @param limit the maximum number of items returns
+   * @return a splitter with the desired configuration
+   * @since 9.0
+   */
+  @CheckReturnValue
+  public Splitter limit(int limit) {
+    checkArgument(limit > 0, "must be greater than zero: %s", limit);
+    return new Splitter(strategy, omitEmptyStrings, trimmer, limit);
+  }
+
+  /**
+   * Returns a splitter that behaves equivalently to {@code this} splitter, but
+   * automatically removes leading and trailing {@linkplain
+   * CharMatcher#WHITESPACE whitespace} from each returned substring; equivalent
+   * to {@code trimResults(CharMatcher.WHITESPACE)}. For example, {@code
+   * Splitter.on(',').trimResults().split(" a, b ,c ")} returns an iterable
+   * containing {@code ["a", "b", "c"]}.
+   *
+   * @return a splitter with the desired configuration
+   */
+  @CheckReturnValue
+  public Splitter trimResults() {
+    return trimResults(CharMatcher.WHITESPACE);
+  }
+
+  /**
+   * Returns a splitter that behaves equivalently to {@code this} splitter, but
+   * removes all leading or trailing characters matching the given {@code
+   * CharMatcher} from each returned substring. For example, {@code
+   * Splitter.on(',').trimResults(CharMatcher.is('_')).split("_a ,_b_ ,c__")}
+   * returns an iterable containing {@code ["a ", "b_ ", "c"]}.
+   *
+   * @param trimmer a {@link CharMatcher} that determines whether a character
+   *     should be removed from the beginning/end of a subsequence
+   * @return a splitter with the desired configuration
+   */
+  // TODO(kevinb): throw if a trimmer was already specified!
+  @CheckReturnValue
+  public Splitter trimResults(CharMatcher trimmer) {
+    checkNotNull(trimmer);
+    return new Splitter(strategy, omitEmptyStrings, trimmer, limit);
+  }
+
+  /**
+   * Splits {@code sequence} into string components and makes them available
+   * through an {@link Iterator}, which may be lazily evaluated.
+   *
+   * @param sequence the sequence of characters to split
+   * @return an iteration over the segments split from the parameter.
+   */
+  public Iterable<String> split(final CharSequence sequence) {
+    checkNotNull(sequence);
+
+    return new Iterable<String>() {
+      @Override public Iterator<String> iterator() {
+        return spliterator(sequence);
+      }
+      @Override public String toString() {
+        return Joiner.on(", ")
+            .appendTo(new StringBuilder().append('['), this)
+            .append(']')
+            .toString();
+      }
+    };
+  }
+
+  private Iterator<String> spliterator(CharSequence sequence) {
+    return strategy.iterator(this, sequence);
+  }
+
+  /**
+   * Returns a {@code MapSplitter} which splits entries based on this splitter,
+   * and splits entries into keys and values using the specified separator.
+   *
+   * @since 10.0
+   */
+  @CheckReturnValue
+  @Beta
+  public MapSplitter withKeyValueSeparator(String separator) {
+    return withKeyValueSeparator(on(separator));
+  }
+
+  /**
+   * Returns a {@code MapSplitter} which splits entries based on this splitter,
+   * and splits entries into keys and values using the specified key-value
+   * splitter.
+   *
+   * @since 10.0
+   */
+  @CheckReturnValue
+  @Beta
+  public MapSplitter withKeyValueSeparator(Splitter keyValueSplitter) {
+    return new MapSplitter(this, keyValueSplitter);
+  }
+
+  /**
+   * An object that splits strings into maps as {@code Splitter} splits
+   * iterables and lists. Like {@code Splitter}, it is thread-safe and
+   * immutable.
+   *
+   * @since 10.0
+   */
+  @Beta
+  public static final class MapSplitter {
+    private static final String INVALID_ENTRY_MESSAGE =
+        "Chunk [%s] is not a valid entry";
+    private final Splitter outerSplitter;
+    private final Splitter entrySplitter;
+
+    private MapSplitter(Splitter outerSplitter, Splitter entrySplitter) {
+      this.outerSplitter = outerSplitter; // only "this" is passed
+      this.entrySplitter = checkNotNull(entrySplitter);
+    }
+
+    /**
+     * Splits {@code sequence} into substrings, splits each substring into
+     * an entry, and returns an unmodifiable map with each of the entries. For
+     * example, <code>
+     * Splitter.on(';').trimResults().withKeyValueSeparator("=>")
+     * .split("a=>b ; c=>b")
+     * </code> will return a mapping from {@code "a"} to {@code "b"} and
+     * {@code "c"} to {@code b}.
+     *
+     * <p>The returned map preserves the order of the entries from
+     * {@code sequence}.
+     *
+     * @throws IllegalArgumentException if the specified sequence does not split
+     *         into valid map entries, or if there are duplicate keys
+     */
+    public Map<String, String> split(CharSequence sequence) {
+      Map<String, String> map = new LinkedHashMap<String, String>();
+      for (String entry : outerSplitter.split(sequence)) {
+        Iterator<String> entryFields = entrySplitter.spliterator(entry);
+
+        checkArgument(entryFields.hasNext(), INVALID_ENTRY_MESSAGE, entry);
+        String key = entryFields.next();
+        checkArgument(!map.containsKey(key), "Duplicate key [%s] found.", key);
+
+        checkArgument(entryFields.hasNext(), INVALID_ENTRY_MESSAGE, entry);
+        String value = entryFields.next();
+        map.put(key, value);
+
+        checkArgument(!entryFields.hasNext(), INVALID_ENTRY_MESSAGE, entry);
+      }
+      return Collections.unmodifiableMap(map);
+    }
+  }
+
+  private interface Strategy {
+    Iterator<String> iterator(Splitter splitter, CharSequence toSplit);
+  }
+
+  private abstract static class SplittingIterator extends AbstractIterator<String> {
+    final CharSequence toSplit;
+    final CharMatcher trimmer;
+    final boolean omitEmptyStrings;
+
+    /**
+     * Returns the first index in {@code toSplit} at or after {@code start}
+     * that contains the separator.
+     */
+    abstract int separatorStart(int start);
+
+    /**
+     * Returns the first index in {@code toSplit} after {@code
+     * separatorPosition} that does not contain a separator. This method is only
+     * invoked after a call to {@code separatorStart}.
+     */
+    abstract int separatorEnd(int separatorPosition);
+
+    int offset = 0;
+    int limit;
+
+    protected SplittingIterator(Splitter splitter, CharSequence toSplit) {
+      this.trimmer = splitter.trimmer;
+      this.omitEmptyStrings = splitter.omitEmptyStrings;
+      this.limit = splitter.limit;
+      this.toSplit = toSplit;
+    }
+
+    @Override protected String computeNext() {
+      /*
+       * The returned string will be from the end of the last match to the
+       * beginning of the next one. nextStart is the start position of the
+       * returned substring, while offset is the place to start looking for a
+       * separator.
+       */
+      int nextStart = offset;
+      while (offset != -1) {
+        int start = nextStart;
+        int end;
+
+        int separatorPosition = separatorStart(offset);
+        if (separatorPosition == -1) {
+          end = toSplit.length();
+          offset = -1;
+        } else {
+          end = separatorPosition;
+          offset = separatorEnd(separatorPosition);
+        }
+        if (offset == nextStart) {
+          /*
+           * This occurs when some pattern has an empty match, even if it
+           * doesn't match the empty string -- for example, if it requires
+           * lookahead or the like. The offset must be increased to look for
+           * separators beyond this point, without changing the start position
+           * of the next returned substring -- so nextStart stays the same.
+           */
+          offset++;
+          if (offset >= toSplit.length()) {
+            offset = -1;
+          }
+          continue;
+        }
+
+        while (start < end && trimmer.matches(toSplit.charAt(start))) {
+          start++;
+        }
+        while (end > start && trimmer.matches(toSplit.charAt(end - 1))) {
+          end--;
+        }
+
+        if (omitEmptyStrings && start == end) {
+          // Don't include the (unused) separator in next split string.
+          nextStart = offset;
+          continue;
+        }
+
+        if (limit == 1) {
+          // The limit has been reached, return the rest of the string as the
+          // final item.  This is tested after empty string removal so that
+          // empty strings do not count towards the limit.
+          end = toSplit.length();
+          offset = -1;
+          // Since we may have changed the end, we need to trim it again.
+          while (end > start && trimmer.matches(toSplit.charAt(end - 1))) {
+            end--;
+          }
+        } else {
+          limit--;
+        }
+
+        return toSplit.subSequence(start, end).toString();
+      }
+      return endOfData();
+    }
+  }
+}