* Throughout the documentation of this class, the phrase "matching character" * is used to mean "any character {@code c} for which {@code this.matches(c)} * returns {@code true}". * *
* Note: This class deals only with {@code char} values; it does not * understand supplementary Unicode code points in the range {@code 0x10000} to * {@code 0x10FFFF}. Such logical characters are encoded into a {@code String} * using surrogate pairs, and a {@code CharMatcher} treats these just as two * separate characters. * *
* Example usages: * *
* String trimmed = {@link #WHITESPACE WHITESPACE}.{@link #trimFrom trimFrom}(userInput);
* if ({@link #ASCII ASCII}.{@link #matchesAllOf matchesAllOf}(s)) { ... }
*
*
*
* See the Guava User Guide article on
* {@code CharMatcher}.
*
* @author Kevin Bourrillion
* @since 1.0
*/
@Beta // Possibly change from chars to code points; decide constants vs. methods
@GwtCompatible(emulated = true)
public abstract class CharMatcher implements Predicate
* Note: as the reference file evolves, we will modify this constant to
* keep it up to date.
*/
public static final CharMatcher SINGLE_WIDTH = new RangesMatcher("CharMatcher.SINGLE_WIDTH",
new char[] { 0x0000, 0x05be, 0x05d0, 0x05f3, 0x0600, 0x0750, 0x0e00, 0x1e00, 0x2100, 0xfb50, 0xfe70, 0xff61 },
new char[] { 0x04f9, 0x05be, 0x05ea, 0x05f4, 0x06ff, 0x077f, 0x0e7f, 0x20af, 0x213a, 0xfdff, 0xfeff, 0xffdc });
/** Matches any character. */
public static final CharMatcher ANY = new FastMatcher("CharMatcher.ANY") {
@Override
public boolean matches(char c) {
return true;
}
@Override
public int indexIn(CharSequence sequence) {
return (sequence.length() == 0) ? -1 : 0;
}
@Override
public int indexIn(CharSequence sequence, int start) {
int length = sequence.length();
Preconditions.checkPositionIndex(start, length);
return (start == length) ? -1 : start;
}
@Override
public int lastIndexIn(CharSequence sequence) {
return sequence.length() - 1;
}
@Override
public boolean matchesAllOf(CharSequence sequence) {
checkNotNull(sequence);
return true;
}
@Override
public boolean matchesNoneOf(CharSequence sequence) {
return sequence.length() == 0;
}
@Override
public String removeFrom(CharSequence sequence) {
checkNotNull(sequence);
return "";
}
@Override
public String replaceFrom(CharSequence sequence, char replacement) {
char[] array = new char[sequence.length()];
Arrays.fill(array, replacement);
return new String(array);
}
@Override
public String replaceFrom(CharSequence sequence, CharSequence replacement) {
StringBuilder retval = new StringBuilder(sequence.length() * replacement.length());
for (int i = 0; i < sequence.length(); i++) {
retval.append(replacement);
}
return retval.toString();
}
@Override
public String collapseFrom(CharSequence sequence, char replacement) {
return (sequence.length() == 0) ? "" : String.valueOf(replacement);
}
@Override
public String trimFrom(CharSequence sequence) {
checkNotNull(sequence);
return "";
}
@Override
public int countIn(CharSequence sequence) {
return sequence.length();
}
@Override
public CharMatcher and(CharMatcher other) {
return checkNotNull(other);
}
@Override
public CharMatcher or(CharMatcher other) {
checkNotNull(other);
return this;
}
@Override
public CharMatcher negate() {
return NONE;
}
};
/** Matches no characters. */
public static final CharMatcher NONE = new FastMatcher("CharMatcher.NONE") {
@Override
public boolean matches(char c) {
return false;
}
@Override
public int indexIn(CharSequence sequence) {
checkNotNull(sequence);
return -1;
}
@Override
public int indexIn(CharSequence sequence, int start) {
int length = sequence.length();
Preconditions.checkPositionIndex(start, length);
return -1;
}
@Override
public int lastIndexIn(CharSequence sequence) {
checkNotNull(sequence);
return -1;
}
@Override
public boolean matchesAllOf(CharSequence sequence) {
return sequence.length() == 0;
}
@Override
public boolean matchesNoneOf(CharSequence sequence) {
checkNotNull(sequence);
return true;
}
@Override
public String removeFrom(CharSequence sequence) {
return sequence.toString();
}
@Override
public String replaceFrom(CharSequence sequence, char replacement) {
return sequence.toString();
}
@Override
public String replaceFrom(CharSequence sequence, CharSequence replacement) {
checkNotNull(replacement);
return sequence.toString();
}
@Override
public String collapseFrom(CharSequence sequence, char replacement) {
return sequence.toString();
}
@Override
public String trimFrom(CharSequence sequence) {
return sequence.toString();
}
@Override
public String trimLeadingFrom(CharSequence sequence) {
return sequence.toString();
}
@Override
public String trimTrailingFrom(CharSequence sequence) {
return sequence.toString();
}
@Override
public int countIn(CharSequence sequence) {
checkNotNull(sequence);
return 0;
}
@Override
public CharMatcher and(CharMatcher other) {
checkNotNull(other);
return this;
}
@Override
public CharMatcher or(CharMatcher other) {
return checkNotNull(other);
}
@Override
public CharMatcher negate() {
return ANY;
}
};
// Static factories
/**
* Returns a {@code char} matcher that matches only one specified character.
*/
public static CharMatcher is(final char match) {
String description = "CharMatcher.is('" + showCharacter(match) + "')";
return new FastMatcher(description) {
@Override
public boolean matches(char c) {
return c == match;
}
@Override
public String replaceFrom(CharSequence sequence, char replacement) {
return sequence.toString().replace(match, replacement);
}
@Override
public CharMatcher and(CharMatcher other) {
return other.matches(match) ? this : NONE;
}
@Override
public CharMatcher or(CharMatcher other) {
return other.matches(match) ? other : super.or(other);
}
@Override
public CharMatcher negate() {
return isNot(match);
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
table.set(match);
}
};
}
/**
* Returns a {@code char} matcher that matches any character except the one
* specified.
*
*
* To negate another {@code CharMatcher}, use {@link #negate()}.
*/
public static CharMatcher isNot(final char match) {
String description = "CharMatcher.isNot('" + showCharacter(match) + "')";
return new FastMatcher(description) {
@Override
public boolean matches(char c) {
return c != match;
}
@Override
public CharMatcher and(CharMatcher other) {
return other.matches(match) ? super.and(other) : other;
}
@Override
public CharMatcher or(CharMatcher other) {
return other.matches(match) ? ANY : this;
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
table.set(0, match);
table.set(match + 1, Character.MAX_VALUE + 1);
}
@Override
public CharMatcher negate() {
return is(match);
}
};
}
/**
* Returns a {@code char} matcher that matches any character present in the
* given character sequence.
*/
public static CharMatcher anyOf(final CharSequence sequence) {
switch (sequence.length()) {
case 0:
return NONE;
case 1:
return is(sequence.charAt(0));
case 2:
return isEither(sequence.charAt(0), sequence.charAt(1));
default:
// continue below to handle the general case
}
// TODO(user): is it potentially worth just going ahead and building a
// precomputed matcher?
final char[] chars = sequence.toString().toCharArray();
Arrays.sort(chars);
StringBuilder description = new StringBuilder("CharMatcher.anyOf(\"");
for (char c : chars) {
description.append(showCharacter(c));
}
description.append("\")");
return new CharMatcher(description.toString()) {
@Override
public boolean matches(char c) {
return Arrays.binarySearch(chars, c) >= 0;
}
@Override
@GwtIncompatible("java.util.BitSet")
void setBits(BitSet table) {
for (char c : chars) {
table.set(c);
}
}
};
}
private static CharMatcher isEither(final char match1, final char match2) {
String description = "CharMatcher.anyOf(\"" + showCharacter(match1) + showCharacter(match2) + "\")";
return new FastMatcher(description) {
@Override
public boolean matches(char c) {
return c == match1 || c == match2;
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
table.set(match1);
table.set(match2);
}
};
}
/**
* Returns a {@code char} matcher that matches any character not present in the
* given character sequence.
*/
public static CharMatcher noneOf(CharSequence sequence) {
return anyOf(sequence).negate();
}
/**
* Returns a {@code char} matcher that matches any character in a given range
* (both endpoints are inclusive). For example, to match any lowercase letter of
* the English alphabet, use {@code
* CharMatcher.inRange('a', 'z')}.
*
* @throws IllegalArgumentException if {@code endInclusive < startInclusive}
*/
public static CharMatcher inRange(final char startInclusive, final char endInclusive) {
checkArgument(endInclusive >= startInclusive);
String description = "CharMatcher.inRange('" + showCharacter(startInclusive) + "', '"
+ showCharacter(endInclusive) + "')";
return inRange(startInclusive, endInclusive, description);
}
static CharMatcher inRange(final char startInclusive, final char endInclusive, String description) {
return new FastMatcher(description) {
@Override
public boolean matches(char c) {
return startInclusive <= c && c <= endInclusive;
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
table.set(startInclusive, endInclusive + 1);
}
};
}
/**
* Returns a matcher with identical behavior to the given
* {@link Character}-based predicate, but which operates on primitive
* {@code char} instances instead.
*/
public static CharMatcher forPredicate(final Predicate predicate) {
checkNotNull(predicate);
if (predicate instanceof CharMatcher) {
return (CharMatcher) predicate;
}
String description = "CharMatcher.forPredicate(" + predicate + ")";
return new CharMatcher(description) {
@Override
public boolean matches(char c) {
return predicate.apply(c);
}
@Override
public boolean apply(Character character) {
return predicate.apply(checkNotNull(character));
}
};
}
// State
final String description;
// Constructors
/**
* Sets the {@code toString()} from the given description.
*/
CharMatcher(String description) {
this.description = description;
}
/**
* Constructor for use by subclasses. When subclassing, you may want to override
* {@code toString()} to provide a useful description.
*/
protected CharMatcher() {
description = super.toString();
}
// Abstract methods
/** Determines a true or false value for the given character. */
public abstract boolean matches(char c);
// Non-static factories
/**
* Returns a matcher that matches any character not matched by this matcher.
*/
public CharMatcher negate() {
return new NegatedMatcher(this);
}
private static class NegatedMatcher extends CharMatcher {
final CharMatcher original;
NegatedMatcher(String toString, CharMatcher original) {
super(toString);
this.original = original;
}
NegatedMatcher(CharMatcher original) {
this(original + ".negate()", original);
}
@Override
public boolean matches(char c) {
return !original.matches(c);
}
@Override
public boolean matchesAllOf(CharSequence sequence) {
return original.matchesNoneOf(sequence);
}
@Override
public boolean matchesNoneOf(CharSequence sequence) {
return original.matchesAllOf(sequence);
}
@Override
public int countIn(CharSequence sequence) {
return sequence.length() - original.countIn(sequence);
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
BitSet tmp = new BitSet();
original.setBits(tmp);
tmp.flip(Character.MIN_VALUE, Character.MAX_VALUE + 1);
table.or(tmp);
}
@Override
public CharMatcher negate() {
return original;
}
@Override
CharMatcher withToString(String description) {
return new NegatedMatcher(description, original);
}
}
/**
* Returns a matcher that matches any character matched by both this matcher and
* {@code other}.
*/
public CharMatcher and(CharMatcher other) {
return new And(this, checkNotNull(other));
}
private static class And extends CharMatcher {
final CharMatcher first;
final CharMatcher second;
And(CharMatcher a, CharMatcher b) {
this(a, b, "CharMatcher.and(" + a + ", " + b + ")");
}
And(CharMatcher a, CharMatcher b, String description) {
super(description);
first = checkNotNull(a);
second = checkNotNull(b);
}
@Override
public boolean matches(char c) {
return first.matches(c) && second.matches(c);
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
BitSet tmp1 = new BitSet();
first.setBits(tmp1);
BitSet tmp2 = new BitSet();
second.setBits(tmp2);
tmp1.and(tmp2);
table.or(tmp1);
}
@Override
CharMatcher withToString(String description) {
return new And(first, second, description);
}
}
/**
* Returns a matcher that matches any character matched by either this matcher
* or {@code other}.
*/
public CharMatcher or(CharMatcher other) {
return new Or(this, checkNotNull(other));
}
private static class Or extends CharMatcher {
final CharMatcher first;
final CharMatcher second;
Or(CharMatcher a, CharMatcher b, String description) {
super(description);
first = checkNotNull(a);
second = checkNotNull(b);
}
Or(CharMatcher a, CharMatcher b) {
this(a, b, "CharMatcher.or(" + a + ", " + b + ")");
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
first.setBits(table);
second.setBits(table);
}
@Override
public boolean matches(char c) {
return first.matches(c) || second.matches(c);
}
@Override
CharMatcher withToString(String description) {
return new Or(first, second, description);
}
}
/**
* Returns a {@code char} matcher functionally equivalent to this one, but which
* may be faster to query than the original; your mileage may vary.
* Precomputation takes time and is likely to be worthwhile only if the
* precomputed matcher is queried many thousands of times.
*
*
* This method has no effect (returns {@code this}) when called in GWT: it's
* unclear whether a precomputed matcher is faster, but it certainly consumes
* more memory, which doesn't seem like a worthwhile tradeoff in a browser.
*/
public CharMatcher precomputed() {
return Platform.precomputeCharMatcher(this);
}
/**
* Subclasses should provide a new CharMatcher with the same characteristics as
* {@code this}, but with their {@code toString} method overridden with the new
* description.
*
*
* This is unsupported by default.
*/
CharMatcher withToString(String description) {
throw new UnsupportedOperationException();
}
private static final int DISTINCT_CHARS = Character.MAX_VALUE - Character.MIN_VALUE + 1;
/**
* This is the actual implementation of {@link #precomputed}, but we bounce
* calls through a method on {@link Platform} so that we can have different
* behavior in GWT.
*
*
* This implementation tries to be smart in a number of ways. It recognizes
* cases where the negation is cheaper to precompute than the matcher itself; it
* tries to build small hash tables for matchers that only match a few
* characters, and so on. In the worst-case scenario, it constructs an
* eight-kilobyte bit array and queries that. In many situations this produces a
* matcher which is faster to query than the original.
*/
@GwtIncompatible("java.util.BitSet")
CharMatcher precomputedInternal() {
final BitSet table = new BitSet();
setBits(table);
int totalCharacters = table.cardinality();
if (totalCharacters * 2 <= DISTINCT_CHARS) {
return precomputedPositive(totalCharacters, table, description);
} else {
// TODO(user): is it worth it to worry about the last character of large
// matchers?
table.flip(Character.MIN_VALUE, Character.MAX_VALUE + 1);
int negatedCharacters = DISTINCT_CHARS - totalCharacters;
String suffix = ".negate()";
String negatedDescription = description.endsWith(suffix)
? description.substring(0, description.length() - suffix.length())
: description + suffix;
return new NegatedFastMatcher(toString(),
precomputedPositive(negatedCharacters, table, negatedDescription));
}
}
/**
* A matcher for which precomputation will not yield any significant benefit.
*/
abstract static class FastMatcher extends CharMatcher {
FastMatcher() {
super();
}
FastMatcher(String description) {
super(description);
}
@Override
public final CharMatcher precomputed() {
return this;
}
@Override
public CharMatcher negate() {
return new NegatedFastMatcher(this);
}
}
static final class NegatedFastMatcher extends NegatedMatcher {
NegatedFastMatcher(CharMatcher original) {
super(original);
}
NegatedFastMatcher(String toString, CharMatcher original) {
super(toString, original);
}
@Override
public final CharMatcher precomputed() {
return this;
}
@Override
CharMatcher withToString(String description) {
return new NegatedFastMatcher(description, original);
}
}
/**
* Helper method for {@link #precomputedInternal} that doesn't test if the
* negation is cheaper.
*/
@GwtIncompatible("java.util.BitSet")
private static CharMatcher precomputedPositive(int totalCharacters, BitSet table, String description) {
switch (totalCharacters) {
case 0:
return NONE;
case 1:
return is((char) table.nextSetBit(0));
case 2:
char c1 = (char) table.nextSetBit(0);
char c2 = (char) table.nextSetBit(c1 + 1);
return isEither(c1, c2);
default:
return isSmall(totalCharacters, table.length()) ? SmallCharMatcher.from(table, description)
: new BitSetMatcher(table, description);
}
}
@GwtIncompatible("SmallCharMatcher")
private static boolean isSmall(int totalCharacters, int tableLength) {
return totalCharacters <= SmallCharMatcher.MAX_SIZE && tableLength > (totalCharacters * 4 * Character.SIZE);
// err on the side of BitSetMatcher
}
@GwtIncompatible("java.util.BitSet")
private static class BitSetMatcher extends FastMatcher {
private final BitSet table;
private BitSetMatcher(BitSet table, String description) {
super(description);
if (table.length() + Long.SIZE < table.size()) {
table = (BitSet) table.clone();
// If only we could actually call BitSet.trimToSize() ourselves...
}
this.table = table;
}
@Override
public boolean matches(char c) {
return table.get(c);
}
@Override
void setBits(BitSet bitSet) {
bitSet.or(table);
}
}
/**
* Sets bits in {@code table} matched by this matcher.
*/
@GwtIncompatible("java.util.BitSet")
void setBits(BitSet table) {
for (int c = Character.MAX_VALUE; c >= Character.MIN_VALUE; c--) {
if (matches((char) c)) {
table.set(c);
}
}
}
// Text processing routines
/**
* Returns {@code true} if a character sequence contains at least one matching
* character. Equivalent to {@code !matchesNoneOf(sequence)}.
*
*
* The default implementation iterates over the sequence, invoking
* {@link #matches} for each character, until this returns {@code true} or the
* end is reached.
*
* @param sequence the character sequence to examine, possibly empty
* @return {@code true} if this matcher matches at least one character in the
* sequence
* @since 8.0
*/
public boolean matchesAnyOf(CharSequence sequence) {
return !matchesNoneOf(sequence);
}
/**
* Returns {@code true} if a character sequence contains only matching
* characters.
*
*
* The default implementation iterates over the sequence, invoking
* {@link #matches} for each character, until this returns {@code false} or the
* end is reached.
*
* @param sequence the character sequence to examine, possibly empty
* @return {@code true} if this matcher matches every character in the sequence,
* including when the sequence is empty
*/
public boolean matchesAllOf(CharSequence sequence) {
for (int i = sequence.length() - 1; i >= 0; i--) {
if (!matches(sequence.charAt(i))) {
return false;
}
}
return true;
}
/**
* Returns {@code true} if a character sequence contains no matching characters.
* Equivalent to {@code !matchesAnyOf(sequence)}.
*
*
* The default implementation iterates over the sequence, invoking
* {@link #matches} for each character, until this returns {@code false} or the
* end is reached.
*
* @param sequence the character sequence to examine, possibly empty
* @return {@code true} if this matcher matches every character in the sequence,
* including when the sequence is empty
*/
public boolean matchesNoneOf(CharSequence sequence) {
return indexIn(sequence) == -1;
}
/**
* Returns the index of the first matching character in a character sequence, or
* {@code -1} if no matching character is present.
*
*
* The default implementation iterates over the sequence in forward order
* calling {@link #matches} for each character.
*
* @param sequence the character sequence to examine from the beginning
* @return an index, or {@code -1} if no character matches
*/
public int indexIn(CharSequence sequence) {
int length = sequence.length();
for (int i = 0; i < length; i++) {
if (matches(sequence.charAt(i))) {
return i;
}
}
return -1;
}
/**
* Returns the index of the first matching character in a character sequence,
* starting from a given position, or {@code -1} if no character matches after
* that position.
*
*
* The default implementation iterates over the sequence in forward order,
* beginning at {@code
* start}, calling {@link #matches} for each character.
*
* @param sequence the character sequence to examine
* @param start the first index to examine; must be nonnegative and no
* greater than {@code
* sequence.length()}
* @return the index of the first matching character, guaranteed to be no less
* than {@code start}, or {@code -1} if no character matches
* @throws IndexOutOfBoundsException if start is negative or greater than {@code
* sequence.length()}
*/
public int indexIn(CharSequence sequence, int start) {
int length = sequence.length();
Preconditions.checkPositionIndex(start, length);
for (int i = start; i < length; i++) {
if (matches(sequence.charAt(i))) {
return i;
}
}
return -1;
}
/**
* Returns the index of the last matching character in a character sequence, or
* {@code -1} if no matching character is present.
*
*
* The default implementation iterates over the sequence in reverse order
* calling {@link #matches} for each character.
*
* @param sequence the character sequence to examine from the end
* @return an index, or {@code -1} if no character matches
*/
public int lastIndexIn(CharSequence sequence) {
for (int i = sequence.length() - 1; i >= 0; i--) {
if (matches(sequence.charAt(i))) {
return i;
}
}
return -1;
}
/**
* Returns the number of matching characters found in a character sequence.
*/
public int countIn(CharSequence sequence) {
int count = 0;
for (int i = 0; i < sequence.length(); i++) {
if (matches(sequence.charAt(i))) {
count++;
}
}
return count;
}
/**
* Returns a string containing all non-matching characters of a character
* sequence, in order. For example:
*
*
* The default implementation uses {@link #indexIn(CharSequence)} to find the
* first matching character, then iterates the remainder of the sequence calling
* {@link #matches(char)} for each character.
*
* @param sequence the character sequence to replace matching characters in
* @param replacement the character to append to the result string in place of
* each matching character in {@code sequence}
* @return the new string
*/
@CheckReturnValue
public String replaceFrom(CharSequence sequence, char replacement) {
String string = sequence.toString();
int pos = indexIn(string);
if (pos == -1) {
return string;
}
char[] chars = string.toCharArray();
chars[pos] = replacement;
for (int i = pos + 1; i < chars.length; i++) {
if (matches(chars[i])) {
chars[i] = replacement;
}
}
return new String(chars);
}
/**
* Returns a string copy of the input character sequence, with each character
* that matches this matcher replaced by a given replacement sequence. For
* example:
*
*
* Note: If the replacement is a fixed string with only one character,
* you are better off calling {@link #replaceFrom(CharSequence, char)} directly.
*
* @param sequence the character sequence to replace matching characters in
* @param replacement the characters to append to the result string in place of
* each matching character in {@code sequence}
* @return the new string
*/
@CheckReturnValue
public String replaceFrom(CharSequence sequence, CharSequence replacement) {
int replacementLen = replacement.length();
if (replacementLen == 0) {
return removeFrom(sequence);
}
if (replacementLen == 1) {
return replaceFrom(sequence, replacement.charAt(0));
}
String string = sequence.toString();
int pos = indexIn(string);
if (pos == -1) {
return string;
}
int len = string.length();
StringBuilder buf = new StringBuilder((len * 3 / 2) + 16);
int oldpos = 0;
do {
buf.append(string, oldpos, pos);
buf.append(replacement);
oldpos = pos + 1;
pos = indexIn(string, oldpos);
} while (pos != -1);
buf.append(string, oldpos, len);
return buf.toString();
}
/**
* Returns a substring of the input character sequence that omits all characters
* this matcher matches from the beginning and from the end of the string. For
* example:
*
*
* Note that:
*
*
* The default implementation uses {@link #indexIn(CharSequence)} to find the
* first matching character, then iterates the remainder of the sequence calling
* {@link #matches(char)} for each character.
*
* @param sequence the character sequence to replace matching groups of
* characters in
* @param replacement the character to append to the result string in place of
* each group of matching characters in {@code sequence}
* @return the new string
*/
@CheckReturnValue
public String collapseFrom(CharSequence sequence, char replacement) {
// This implementation avoids unnecessary allocation.
int len = sequence.length();
for (int i = 0; i < len; i++) {
char c = sequence.charAt(i);
if (matches(c)) {
if (c == replacement && (i == len - 1 || !matches(sequence.charAt(i + 1)))) {
// a no-op replacement
i++;
} else {
StringBuilder builder = new StringBuilder(len).append(sequence.subSequence(0, i))
.append(replacement);
return finishCollapseFrom(sequence, i + 1, len, replacement, builder, true);
}
}
}
// no replacement needed
return sequence.toString();
}
/**
* Collapses groups of matching characters exactly as {@link #collapseFrom}
* does, except that groups of matching characters at the start or end of the
* sequence are removed without replacement.
*/
@CheckReturnValue
public String trimAndCollapseFrom(CharSequence sequence, char replacement) {
// This implementation avoids unnecessary allocation.
int len = sequence.length();
int first;
int last;
for (first = 0; first < len && matches(sequence.charAt(first)); first++) {
}
for (last = len - 1; last > first && matches(sequence.charAt(last)); last--) {
}
return (first == 0 && last == len - 1) ? collapseFrom(sequence, replacement)
: finishCollapseFrom(sequence, first, last + 1, replacement, new StringBuilder(last + 1 - first),
false);
}
private String finishCollapseFrom(CharSequence sequence, int start, int end, char replacement,
StringBuilder builder, boolean inMatchingGroup) {
for (int i = start; i < end; i++) {
char c = sequence.charAt(i);
if (matches(c)) {
if (!inMatchingGroup) {
builder.append(replacement);
inMatchingGroup = true;
}
} else {
builder.append(c);
inMatchingGroup = false;
}
}
return builder.toString();
}
/**
* @deprecated Provided only to satisfy the {@link Predicate} interface; use
* {@link #matches} instead.
*/
@Deprecated
@Override
public boolean apply(Character character) {
return matches(character);
}
/**
* Returns a string representation of this {@code CharMatcher}, such as
* {@code CharMatcher.or(WHITESPACE, JAVA_DIGIT)}.
*/
@Override
public String toString() {
return description;
}
static final String WHITESPACE_TABLE = new String(new char[] { 0x2002, 0x3000, '\r', 0x0085, 0x200A, 0x2005, 0x2000,
0x3000, 0x2029, 0x000B, 0x3000, 0x2008, 0x2003, 0x205F, 0x3000, 0x1680, 0x0009, 0x0020, 0x2006, 0x2001,
0x202F, 0x00A0, 0x000C, 0x2009, 0x3000, 0x2004, 0x3000, 0x3000, 0x2028, '\n', 0x2007, 0x3000 });
static final int WHITESPACE_MULTIPLIER = 1682554634;
static final int WHITESPACE_SHIFT = Integer.numberOfLeadingZeros(WHITESPACE_TABLE.length() - 1);
/**
* Determines whether a character is whitespace according to the latest Unicode
* standard, as illustrated here.
* This is not the same definition used by other Java APIs. (See a comparison
* of several definitions of "whitespace".)
*
*
* Note: as the Unicode definition evolves, we will modify this constant
* to keep it up to date.
*/
public static final CharMatcher WHITESPACE = new FastMatcher("WHITESPACE") {
@Override
public boolean matches(char c) {
return WHITESPACE_TABLE.charAt((WHITESPACE_MULTIPLIER * c) >>> WHITESPACE_SHIFT) == c;
}
@GwtIncompatible("java.util.BitSet")
@Override
void setBits(BitSet table) {
for (int i = 0; i < WHITESPACE_TABLE.length(); i++) {
table.set(WHITESPACE_TABLE.charAt(i));
}
}
};
}
* {@code
*
* CharMatcher.is('a').removeFrom("bazaar")}
*
*
* ... returns {@code "bzr"}.
*/
@CheckReturnValue
public String removeFrom(CharSequence sequence) {
String string = sequence.toString();
int pos = indexIn(string);
if (pos == -1) {
return string;
}
char[] chars = string.toCharArray();
int spread = 1;
// This unusual loop comes from extensive benchmarking
OUT: while (true) {
pos++;
while (true) {
if (pos == chars.length) {
break OUT;
}
if (matches(chars[pos])) {
break;
}
chars[pos - spread] = chars[pos];
pos++;
}
spread++;
}
return new String(chars, 0, pos - spread);
}
/**
* Returns a string containing all matching characters of a character sequence,
* in order. For example:
*
*
* {@code
*
* CharMatcher.is('a').retainFrom("bazaar")}
*
*
* ... returns {@code "aaa"}.
*/
@CheckReturnValue
public String retainFrom(CharSequence sequence) {
return negate().removeFrom(sequence);
}
/**
* Returns a string copy of the input character sequence, with each character
* that matches this matcher replaced by a given replacement character. For
* example:
*
*
* {@code
*
* CharMatcher.is('a').replaceFrom("radar", 'o')}
*
*
* ... returns {@code "rodor"}.
*
*
* {@code
*
* CharMatcher.is('a').replaceFrom("yaha", "oo")}
*
*
* ... returns {@code "yoohoo"}.
*
*
* {@code
*
* CharMatcher.anyOf("ab").trimFrom("abacatbab")}
*
*
* ... returns {@code "cat"}.
*
*
* {@code
*
* CharMatcher.inRange('\0', ' ').trimFrom(str)}
*
*
* ... is equivalent to {@link String#trim()}.
*/
@CheckReturnValue
public String trimFrom(CharSequence sequence) {
int len = sequence.length();
int first;
int last;
for (first = 0; first < len; first++) {
if (!matches(sequence.charAt(first))) {
break;
}
}
for (last = len - 1; last > first; last--) {
if (!matches(sequence.charAt(last))) {
break;
}
}
return sequence.subSequence(first, last + 1).toString();
}
/**
* Returns a substring of the input character sequence that omits all characters
* this matcher matches from the beginning of the string. For example:
*
*
* {@code
*
* CharMatcher.anyOf("ab").trimLeadingFrom("abacatbab")}
*
*
* ... returns {@code "catbab"}.
*/
@CheckReturnValue
public String trimLeadingFrom(CharSequence sequence) {
int len = sequence.length();
for (int first = 0; first < len; first++) {
if (!matches(sequence.charAt(first))) {
return sequence.subSequence(first, len).toString();
}
}
return "";
}
/**
* Returns a substring of the input character sequence that omits all characters
* this matcher matches from the end of the string. For example:
*
*
* {@code
*
* CharMatcher.anyOf("ab").trimTrailingFrom("abacatbab")}
*
*
* ... returns {@code "abacat"}.
*/
@CheckReturnValue
public String trimTrailingFrom(CharSequence sequence) {
int len = sequence.length();
for (int last = len - 1; last >= 0; last--) {
if (!matches(sequence.charAt(last))) {
return sequence.subSequence(0, last + 1).toString();
}
}
return "";
}
/**
* Returns a string copy of the input character sequence, with each group of
* consecutive characters that match this matcher replaced by a single
* replacement character. For example:
*
*
* {@code
*
* CharMatcher.anyOf("eko").collapseFrom("bookkeeper", '-')}
*
*
* ... returns {@code "b-p-r"}.
*
*