public interface SymbolTable
This interface is used by UnicodeSet to resolve $Variable style references that appear in set patterns. RBBI and Transliteration both independently implement this interface.
A symbol table maintains two kinds of mappings. The first is between symbolic names and their values. For example, if the variable with the name "start" is set to the value "alpha" (perhaps, though not necessarily, through an expression such as "$start=alpha"), then the call lookup("start") will return the char[] array ['a', 'l', 'p', 'h', 'a'].
The second kind of mapping is between character values and UnicodeMatcher objects. This is used by RuleBasedTransliterator, which uses characters in the private use area to represent objects such as UnicodeSets. If U+E015 is mapped to the UnicodeSet [a-z], then lookupMatcher(0xE015) will return the UnicodeSet [a-z].
Finally, a symbol table defines parsing behavior for symbolic names. All symbolic names start with the SYMBOL_REF character. When a parser encounters this character, it calls parseReference() with the position immediately following the SYMBOL_REF. The symbol table parses the name, if there is one, and returns it.
Modifier and Type | Field and Description |
---|---|
static char |
SYMBOL_REF
The character preceding a symbol reference name.
|
Modifier and Type | Method and Description |
---|---|
char[] |
lookup(String s)
Lookup the characters associated with this string and return it.
|
UnicodeMatcher |
lookupMatcher(int ch)
Lookup the UnicodeMatcher associated with the given character, and
return it.
|
String |
parseReference(String text,
ParsePosition pos,
int limit)
Parse a symbol reference name from the given string, starting
at the given position.
|
static final char SYMBOL_REF
char[] lookup(String s)
s
- the symbolic name to lookupUnicodeMatcher lookupMatcher(int ch)
ch
- a 32-bit code point from 0 to 0x10FFFF inclusive.String parseReference(String text, ParsePosition pos, int limit)
text
- the text to parse for the namepos
- on entry, the index of the first character to parse.
This is the character following the SYMBOL_REF character. On
exit, the index after the last parsed character. If the parse
failed, pos is unchanged on exit.limit
- the index after the last character to be parsed.Copyright © 2016 Unicode, Inc. and others.