| Affix Pattern | *Example Unescaped (Formatted) String | *
|---|---|
| abc | *abc | *
| ab- | *ab− | *
| ab'-' | *ab- | *
| ab'' | *ab' | *
* long tag = 0L;
* while (AffixPatternUtils.hasNext(tag, patternString)) {
* tag = AffixPatternUtils.nextToken(tag, patternString);
* int typeOrCp = AffixPatternUtils.getTypeOrCp(tag);
* switch (typeOrCp) {
* case AffixPatternUtils.TYPE_MINUS_SIGN:
* // Current token is a minus sign.
* break;
* case AffixPatternUtils.TYPE_PLUS_SIGN:
* // Current token is a plus sign.
* break;
* case AffixPatternUtils.TYPE_PERCENT:
* // Current token is a percent sign.
* break;
* // ... other types ...
* default:
* // Current token is an arbitrary code point.
* // The variable typeOrCp is the code point.
* break;
* }
* }
*
* @hide Only a subset of ICU is exposed in Android
*/
public class AffixUtils {
private static final int STATE_BASE = 0;
private static final int STATE_FIRST_QUOTE = 1;
private static final int STATE_INSIDE_QUOTE = 2;
private static final int STATE_AFTER_QUOTE = 3;
private static final int STATE_FIRST_CURR = 4;
private static final int STATE_SECOND_CURR = 5;
private static final int STATE_THIRD_CURR = 6;
private static final int STATE_FOURTH_CURR = 7;
private static final int STATE_FIFTH_CURR = 8;
private static final int STATE_OVERFLOW_CURR = 9;
/** Represents a literal character; the value is stored in the code point field. */
private static final int TYPE_CODEPOINT = 0;
/** Represents a minus sign symbol '-'. */
public static final int TYPE_MINUS_SIGN = -1;
/** Represents a plus sign symbol '+'. */
public static final int TYPE_PLUS_SIGN = -2;
// Represents an approximately sign symbol '~'.
public static final int TYPE_APPROXIMATELY_SIGN = -3;
/** Represents a percent sign symbol '%'. */
public static final int TYPE_PERCENT = -4;
/** Represents a permille sign symbol '‰'. */
public static final int TYPE_PERMILLE = -5;
/** Represents a single currency symbol '¤'. */
public static final int TYPE_CURRENCY_SINGLE = -6;
/** Represents a double currency symbol '¤¤'. */
public static final int TYPE_CURRENCY_DOUBLE = -7;
/** Represents a triple currency symbol '¤¤¤'. */
public static final int TYPE_CURRENCY_TRIPLE = -8;
/** Represents a quadruple currency symbol '¤¤¤¤'. */
public static final int TYPE_CURRENCY_QUAD = -9;
/** Represents a quintuple currency symbol '¤¤¤¤¤'. */
public static final int TYPE_CURRENCY_QUINT = -10;
/** Represents a sequence of six or more currency symbols. */
public static final int TYPE_CURRENCY_OVERFLOW = -15;
/**
* @hide Only a subset of ICU is exposed in Android
*/
public static interface SymbolProvider {
public CharSequence getSymbol(int type);
}
/**
* @hide Only a subset of ICU is exposed in Android
*/
public static interface TokenConsumer {
public void consumeToken(int typeOrCp);
}
/**
* Estimates the number of code points present in an unescaped version of the affix pattern string
* (one that would be returned by {@link #unescape}), assuming that all interpolated symbols consume
* one code point and that currencies consume as many code points as their symbol width. Used for
* computing padding width.
*
* @param patternString
* The original string whose width will be estimated.
* @return The length of the unescaped string.
*/
public static int estimateLength(CharSequence patternString) {
if (patternString == null)
return 0;
int state = STATE_BASE;
int offset = 0;
int length = 0;
for (; offset < patternString.length();) {
int cp = Character.codePointAt(patternString, offset);
switch (state) {
case STATE_BASE:
if (cp == '\'') {
// First quote
state = STATE_FIRST_QUOTE;
} else {
// Unquoted symbol
length++;
}
break;
case STATE_FIRST_QUOTE:
if (cp == '\'') {
// Repeated quote
length++;
state = STATE_BASE;
} else {
// Quoted code point
length++;
state = STATE_INSIDE_QUOTE;
}
break;
case STATE_INSIDE_QUOTE:
if (cp == '\'') {
// End of quoted sequence
state = STATE_AFTER_QUOTE;
} else {
// Quoted code point
length++;
}
break;
case STATE_AFTER_QUOTE:
if (cp == '\'') {
// Double quote inside of quoted sequence
length++;
state = STATE_INSIDE_QUOTE;
} else {
// Unquoted symbol
length++;
}
break;
default:
throw new AssertionError();
}
offset += Character.charCount(cp);
}
switch (state) {
case STATE_FIRST_QUOTE:
case STATE_INSIDE_QUOTE:
throw new IllegalArgumentException("Unterminated quote: \"" + patternString + "\"");
default:
break;
}
return length;
}
/**
* Takes a string and escapes (quotes) characters that have special meaning in the affix pattern
* syntax. This function does not reverse-lookup symbols.
*
* * Example input: "-$x"; example output: "'-'$x" * * @param input * The string to be escaped. * @param output * The string builder to which to append the escaped string. * @return The number of chars (UTF-16 code units) appended to the output. */ public static int escape(CharSequence input, StringBuilder output) { if (input == null) return 0; int state = STATE_BASE; int offset = 0; int startLength = output.length(); for (; offset < input.length();) { int cp = Character.codePointAt(input, offset); switch (cp) { case '\'': output.append("''"); break; case '-': case '+': case '%': case '‰': case '¤': if (state == STATE_BASE) { output.append('\''); output.appendCodePoint(cp); state = STATE_INSIDE_QUOTE; } else { output.appendCodePoint(cp); } break; default: if (state == STATE_INSIDE_QUOTE) { output.append('\''); output.appendCodePoint(cp); state = STATE_BASE; } else { output.appendCodePoint(cp); } break; } offset += Character.charCount(cp); } if (state == STATE_INSIDE_QUOTE) { output.append('\''); } return output.length() - startLength; } /** Version of {@link #escape} that returns a String, or null if input is null. */ public static String escape(CharSequence input) { if (input == null) return null; StringBuilder sb = new StringBuilder(); escape(input, sb); return sb.toString(); } public static final NumberFormat.Field getFieldForType(int type) { switch (type) { case TYPE_MINUS_SIGN: return NumberFormat.Field.SIGN; case TYPE_PLUS_SIGN: return NumberFormat.Field.SIGN; case TYPE_APPROXIMATELY_SIGN: return NumberFormat.Field.APPROXIMATELY_SIGN; case TYPE_PERCENT: return NumberFormat.Field.PERCENT; case TYPE_PERMILLE: return NumberFormat.Field.PERMILLE; case TYPE_CURRENCY_SINGLE: return NumberFormat.Field.CURRENCY; case TYPE_CURRENCY_DOUBLE: return NumberFormat.Field.CURRENCY; case TYPE_CURRENCY_TRIPLE: return NumberFormat.Field.CURRENCY; case TYPE_CURRENCY_QUAD: return NumberFormat.Field.CURRENCY; case TYPE_CURRENCY_QUINT: return NumberFormat.Field.CURRENCY; case TYPE_CURRENCY_OVERFLOW: return NumberFormat.Field.CURRENCY; default: throw new AssertionError(); } } /** * Executes the unescape state machine. Replaces the unquoted characters "-", "+", "%", "‰", and "¤" * with the corresponding symbols provided by the {@link SymbolProvider}, and inserts the result into * the FormattedStringBuilder at the requested location. * *
* Example input: "'-'¤x"; example output: "-$x"
*
* @param affixPattern
* The original string to be unescaped.
* @param output
* The FormattedStringBuilder to mutate with the result.
* @param position
* The index into the FormattedStringBuilder to insert the the string.
* @param provider
* An object to generate locale symbols.
* @return The length of the string added to affixPattern.
*/
public static int unescape(
CharSequence affixPattern,
FormattedStringBuilder output,
int position,
SymbolProvider provider,
NumberFormat.Field field) {
assert affixPattern != null;
int length = 0;
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
int typeOrCp = getTypeOrCp(tag);
if (typeOrCp == TYPE_CURRENCY_OVERFLOW) {
// Don't go to the provider for this special case
length += output.insertCodePoint(position + length, 0xFFFD, NumberFormat.Field.CURRENCY);
} else if (typeOrCp < 0) {
length += output.insert(position + length,
provider.getSymbol(typeOrCp),
getFieldForType(typeOrCp));
} else {
length += output.insertCodePoint(position + length, typeOrCp, field);
}
}
return length;
}
/**
* Sames as {@link #unescape}, but only calculates the length or code point count. More efficient
* than {@link #unescape} if you only need the length but not the string itself.
*
* @param affixPattern
* The original string to be unescaped.
* @param lengthOrCount
* true to count length (UTF-16 code units); false to count code points
* @param provider
* An object to generate locale symbols.
* @return The number of code points in the unescaped string.
*/
public static int unescapedCount(
CharSequence affixPattern,
boolean lengthOrCount,
SymbolProvider provider) {
int length = 0;
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
int typeOrCp = getTypeOrCp(tag);
if (typeOrCp == TYPE_CURRENCY_OVERFLOW) {
// U+FFFD is one char
length += 1;
} else if (typeOrCp < 0) {
CharSequence symbol = provider.getSymbol(typeOrCp);
length += lengthOrCount ? symbol.length()
: Character.codePointCount(symbol, 0, symbol.length());
} else {
length += lengthOrCount ? Character.charCount(typeOrCp) : 1;
}
}
return length;
}
/**
* Checks whether the given affix pattern contains at least one token of the given type, which is one
* of the constants "TYPE_" in {@link AffixUtils}.
*
* @param affixPattern
* The affix pattern to check.
* @param type
* The token type.
* @return true if the affix pattern contains the given token type; false otherwise.
*/
public static boolean containsType(CharSequence affixPattern, int type) {
if (affixPattern == null || affixPattern.length() == 0) {
return false;
}
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
if (getTypeOrCp(tag) == type) {
return true;
}
}
return false;
}
/**
* Checks whether the specified affix pattern has any unquoted currency symbols ("¤").
*
* @param affixPattern
* The string to check for currency symbols.
* @return true if the literal has at least one unquoted currency symbol; false otherwise.
*/
public static boolean hasCurrencySymbols(CharSequence affixPattern) {
if (affixPattern == null || affixPattern.length() == 0)
return false;
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
int typeOrCp = getTypeOrCp(tag);
if (typeOrCp < 0 && getFieldForType(typeOrCp) == NumberFormat.Field.CURRENCY) {
return true;
}
}
return false;
}
/**
* Replaces all occurrences of tokens with the given type with the given replacement char.
*
* @param affixPattern
* The source affix pattern (does not get modified).
* @param type
* The token type.
* @param replacementChar
* The char to substitute in place of chars of the given token type.
* @return A string containing the new affix pattern.
*/
public static String replaceType(CharSequence affixPattern, int type, char replacementChar) {
if (affixPattern == null || affixPattern.length() == 0)
return "";
char[] chars = affixPattern.toString().toCharArray();
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
if (getTypeOrCp(tag) == type) {
int offset = getOffset(tag);
chars[offset - 1] = replacementChar;
}
}
return new String(chars);
}
/**
* Returns whether the given affix pattern contains only symbols and ignorables as defined by the
* given ignorables set.
*/
public static boolean containsOnlySymbolsAndIgnorables(
CharSequence affixPattern,
UnicodeSet ignorables) {
if (affixPattern == null) {
return true;
}
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
int typeOrCp = getTypeOrCp(tag);
if (typeOrCp >= 0 && !ignorables.contains(typeOrCp)) {
return false;
}
}
return true;
}
/**
* Iterates over the affix pattern, calling the TokenConsumer for each token.
*/
public static void iterateWithConsumer(CharSequence affixPattern, TokenConsumer consumer) {
assert affixPattern != null;
long tag = 0L;
while (hasNext(tag, affixPattern)) {
tag = nextToken(tag, affixPattern);
int typeOrCp = getTypeOrCp(tag);
consumer.consumeToken(typeOrCp);
}
}
/**
* Returns the next token from the affix pattern.
*
* @param tag
* A bitmask used for keeping track of state from token to token. The initial value should
* be 0L.
* @param patternString
* The affix pattern.
* @return The bitmask tag to pass to the next call of this method to retrieve the following token
* (never negative), or -1 if there were no more tokens in the affix pattern.
* @see #hasNext
*/
private static long nextToken(long tag, CharSequence patternString) {
int offset = getOffset(tag);
int state = getState(tag);
for (; offset < patternString.length();) {
int cp = Character.codePointAt(patternString, offset);
int count = Character.charCount(cp);
switch (state) {
case STATE_BASE:
switch (cp) {
case '\'':
state = STATE_FIRST_QUOTE;
offset += count;
// continue to the next code point
break;
case '-':
return makeTag(offset + count, TYPE_MINUS_SIGN, STATE_BASE, 0);
case '+':
return makeTag(offset + count, TYPE_PLUS_SIGN, STATE_BASE, 0);
case '~':
return makeTag(offset + count, TYPE_APPROXIMATELY_SIGN, STATE_BASE, 0);
case '%':
return makeTag(offset + count, TYPE_PERCENT, STATE_BASE, 0);
case '‰':
return makeTag(offset + count, TYPE_PERMILLE, STATE_BASE, 0);
case '¤':
state = STATE_FIRST_CURR;
offset += count;
// continue to the next code point
break;
default:
return makeTag(offset + count, TYPE_CODEPOINT, STATE_BASE, cp);
}
break;
case STATE_FIRST_QUOTE:
if (cp == '\'') {
return makeTag(offset + count, TYPE_CODEPOINT, STATE_BASE, cp);
} else {
return makeTag(offset + count, TYPE_CODEPOINT, STATE_INSIDE_QUOTE, cp);
}
case STATE_INSIDE_QUOTE:
if (cp == '\'') {
state = STATE_AFTER_QUOTE;
offset += count;
// continue to the next code point
break;
} else {
return makeTag(offset + count, TYPE_CODEPOINT, STATE_INSIDE_QUOTE, cp);
}
case STATE_AFTER_QUOTE:
if (cp == '\'') {
return makeTag(offset + count, TYPE_CODEPOINT, STATE_INSIDE_QUOTE, cp);
} else {
state = STATE_BASE;
// re-evaluate this code point
break;
}
case STATE_FIRST_CURR:
if (cp == '¤') {
state = STATE_SECOND_CURR;
offset += count;
// continue to the next code point
break;
} else {
return makeTag(offset, TYPE_CURRENCY_SINGLE, STATE_BASE, 0);
}
case STATE_SECOND_CURR:
if (cp == '¤') {
state = STATE_THIRD_CURR;
offset += count;
// continue to the next code point
break;
} else {
return makeTag(offset, TYPE_CURRENCY_DOUBLE, STATE_BASE, 0);
}
case STATE_THIRD_CURR:
if (cp == '¤') {
state = STATE_FOURTH_CURR;
offset += count;
// continue to the next code point
break;
} else {
return makeTag(offset, TYPE_CURRENCY_TRIPLE, STATE_BASE, 0);
}
case STATE_FOURTH_CURR:
if (cp == '¤') {
state = STATE_FIFTH_CURR;
offset += count;
// continue to the next code point
break;
} else {
return makeTag(offset, TYPE_CURRENCY_QUAD, STATE_BASE, 0);
}
case STATE_FIFTH_CURR:
if (cp == '¤') {
state = STATE_OVERFLOW_CURR;
offset += count;
// continue to the next code point
break;
} else {
return makeTag(offset, TYPE_CURRENCY_QUINT, STATE_BASE, 0);
}
case STATE_OVERFLOW_CURR:
if (cp == '¤') {
offset += count;
// continue to the next code point and loop back to this state
break;
} else {
return makeTag(offset, TYPE_CURRENCY_OVERFLOW, STATE_BASE, 0);
}
default:
throw new AssertionError();
}
}
// End of string
switch (state) {
case STATE_BASE:
// No more tokens in string.
return -1L;
case STATE_FIRST_QUOTE:
case STATE_INSIDE_QUOTE:
// For consistent behavior with the JDK and ICU 58, throw an exception here.
throw new IllegalArgumentException(
"Unterminated quote in pattern affix: \"" + patternString + "\"");
case STATE_AFTER_QUOTE:
// No more tokens in string.
return -1L;
case STATE_FIRST_CURR:
return makeTag(offset, TYPE_CURRENCY_SINGLE, STATE_BASE, 0);
case STATE_SECOND_CURR:
return makeTag(offset, TYPE_CURRENCY_DOUBLE, STATE_BASE, 0);
case STATE_THIRD_CURR:
return makeTag(offset, TYPE_CURRENCY_TRIPLE, STATE_BASE, 0);
case STATE_FOURTH_CURR:
return makeTag(offset, TYPE_CURRENCY_QUAD, STATE_BASE, 0);
case STATE_FIFTH_CURR:
return makeTag(offset, TYPE_CURRENCY_QUINT, STATE_BASE, 0);
case STATE_OVERFLOW_CURR:
return makeTag(offset, TYPE_CURRENCY_OVERFLOW, STATE_BASE, 0);
default:
throw new AssertionError();
}
}
/**
* Returns whether the affix pattern string has any more tokens to be retrieved from a call to
* {@link #nextToken}.
*
* @param tag
* The bitmask tag of the previous token, as returned by {@link #nextToken}.
* @param string
* The affix pattern.
* @return true if there are more tokens to consume; false otherwise.
*/
private static boolean hasNext(long tag, CharSequence string) {
assert tag >= 0;
int state = getState(tag);
int offset = getOffset(tag);
// Special case: the last character in string is an end quote.
if (state == STATE_INSIDE_QUOTE
&& offset == string.length() - 1
&& string.charAt(offset) == '\'') {
return false;
} else if (state != STATE_BASE) {
return true;
} else {
return offset < string.length();
}
}
/**
* This function helps determine the identity of the token consumed by {@link #nextToken}. Converts
* from a bitmask tag, based on a call to {@link #nextToken}, to its corresponding symbol type or
* code point.
*
* @param tag
* The bitmask tag of the current token, as returned by {@link #nextToken}.
* @return If less than zero, a symbol type corresponding to one of the TYPE_ constants,
* such as {@link #TYPE_MINUS_SIGN}. If greater than or equal to zero, a literal code point.
*/
private static int getTypeOrCp(long tag) {
assert tag >= 0;
int type = getType(tag);
return (type == TYPE_CODEPOINT) ? getCodePoint(tag) : -type;
}
/**
* Encodes the given values into a 64-bit tag.
*
*