395 lines
17 KiB
C++
395 lines
17 KiB
C++
/*
|
|
* Copyright (C) {1999-2001}, International Business Machines Corporation and others. All Rights Reserved.
|
|
**********************************************************************
|
|
* Date Name Description
|
|
* 11/17/99 aliu Creation.
|
|
**********************************************************************
|
|
*/
|
|
#ifndef RBT_RULE_H
|
|
#define RBT_RULE_H
|
|
|
|
#include "unicode/unistr.h"
|
|
#include "unicode/utrans.h"
|
|
|
|
class Replaceable;
|
|
class TransliterationRuleData;
|
|
class UnicodeFilter;
|
|
|
|
/**
|
|
* A transliteration rule used by
|
|
* <code>RuleBasedTransliterator</code>.
|
|
* <code>TransliterationRule</code> is an immutable object.
|
|
*
|
|
* <p>A rule consists of an input pattern and an output string. When
|
|
* the input pattern is matched, the output string is emitted. The
|
|
* input pattern consists of zero or more characters which are matched
|
|
* exactly (the key) and optional context. Context must match if it
|
|
* is specified. Context may be specified before the key, after the
|
|
* key, or both. The key, preceding context, and following context
|
|
* may contain variables. Variables represent a set of Unicode
|
|
* characters, such as the letters <i>a</i> through <i>z</i>.
|
|
* Variables are detected by looking up each character in a supplied
|
|
* variable list to see if it has been so defined.
|
|
*
|
|
* @author Alan Liu
|
|
*/
|
|
class TransliterationRule {
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constants returned by <code>getMatchDegree()</code> indicating
|
|
* the degree of match between the text and this rule.
|
|
* @see #getMatchDegree
|
|
*/
|
|
enum {
|
|
/**
|
|
* Constant returned by <code>getMatchDegree()</code>
|
|
* indicating a mismatch between the text and this rule. One
|
|
* or more characters of the context or key do not match the
|
|
* text.
|
|
*/
|
|
MISMATCH,
|
|
|
|
/**
|
|
* Constant returned by <code>getMatchDegree()</code>
|
|
* indicating a partial match between the text and this rule.
|
|
* All characters of the text match the corresponding context
|
|
* or key, but more characters are required for a complete
|
|
* match. There are some key or context characters at the end
|
|
* of the pattern that remain unmatched because the text isn't
|
|
* long enough.
|
|
*/
|
|
PARTIAL_MATCH,
|
|
|
|
/**
|
|
* Constant returned by <code>getMatchDegree()</code>
|
|
* indicating a complete match between the text and this rule.
|
|
* The text matches all context and key characters.
|
|
*/
|
|
FULL_MATCH
|
|
};
|
|
|
|
/**
|
|
* The character at index i, where i < contextStart || i >= contextLimit,
|
|
* is ETHER. This allows explicit matching by rules and UnicodeSets
|
|
* of text outside the context. In traditional terms, this allows anchoring
|
|
* at the start and/or end.
|
|
*/
|
|
static const UChar ETHER;
|
|
|
|
private:
|
|
|
|
/**
|
|
* The string that must be matched, consisting of the anteContext, key,
|
|
* and postContext, concatenated together, in that order. Some components
|
|
* may be empty (zero length).
|
|
* @see anteContextLength
|
|
* @see keyLength
|
|
*/
|
|
UnicodeString pattern;
|
|
|
|
/**
|
|
* The string that is emitted if the key, anteContext, and postContext
|
|
* are matched.
|
|
*/
|
|
UnicodeString output;
|
|
|
|
/**
|
|
* Array of segments. These are segments of the input string that may be
|
|
* referenced and appear in the output string. Each segment is stored as an
|
|
* offset, limit pair. Segments are referenced by a 1-based index;
|
|
* reference i thus includes characters at offset segments[2*i-2] to
|
|
* segments[2*i-1]-1 in the pattern string.
|
|
*
|
|
* In the output string, a segment reference is indicated by a character in
|
|
* a special range, as defined by RuleBasedTransliterator.Data.
|
|
*
|
|
* Most rules have no segments, in which case segments is null, and the
|
|
* output string need not be checked for segment reference characters.
|
|
*/
|
|
int32_t* segments;
|
|
|
|
/**
|
|
* The length of the string that must match before the key. If
|
|
* zero, then there is no matching requirement before the key.
|
|
* Substring [0,anteContextLength) of pattern is the anteContext.
|
|
*/
|
|
int32_t anteContextLength;
|
|
|
|
/**
|
|
* The length of the key. Substring [anteContextLength,
|
|
* anteContextLength + keyLength) is the key.
|
|
|
|
*/
|
|
int32_t keyLength;
|
|
|
|
/**
|
|
* The position of the cursor after emitting the output string, from 0 to
|
|
* output.length(). For most rules with no special cursor specification,
|
|
* the cursorPos is output.length().
|
|
*/
|
|
int32_t cursorPos;
|
|
|
|
public:
|
|
|
|
/**
|
|
* Construct a new rule with the given input, output text, and other
|
|
* attributes. A cursor position may be specified for the output text.
|
|
* @param input input string, including key and optional ante and
|
|
* post context
|
|
* @param anteContextPos offset into input to end of ante context, or -1 if
|
|
* none. Must be <= input.length() if not -1.
|
|
* @param postContextPos offset into input to start of post context, or -1
|
|
* if none. Must be <= input.length() if not -1, and must be >=
|
|
* anteContextPos.
|
|
* @param output output string
|
|
* @param cursorPosition offset into output at which cursor is located, or -1 if
|
|
* none. If less than zero, then the cursor is placed after the
|
|
* <code>output</code>; that is, -1 is equivalent to
|
|
* <code>output.length()</code>. If greater than
|
|
* <code>output.length()</code> then an exception is thrown.
|
|
* @param cursorOffset an offset to be added to cursorPos to position the
|
|
* cursor either in the ante context, if < 0, or in the post context, if >
|
|
* 0. For example, the rule "abc{def} > | @@@ xyz;" changes "def" to
|
|
* "xyz" and moves the cursor to before "a". It would have a cursorOffset
|
|
* of -3.
|
|
* @param adoptedSegs array of 2n integers. Each of n pairs consists of offset,
|
|
* limit for a segment of the input string. Characters in the output string
|
|
* refer to these segments if they are in a special range determined by the
|
|
* associated RuleBasedTransliterator.Data object. May be null if there are
|
|
* no segments.
|
|
* @param anchorStart TRUE if the the rule is anchored on the left to
|
|
* the context start
|
|
* @param anchorEnd TRUE if the rule is anchored on the right to the
|
|
* context limit
|
|
*/
|
|
TransliterationRule(const UnicodeString& input,
|
|
int32_t anteContextPos, int32_t postContextPos,
|
|
const UnicodeString& outputStr,
|
|
int32_t cursorPosition, int32_t cursorOffset,
|
|
int32_t* adoptedSegs,
|
|
UBool anchorStart, UBool anchorEnd,
|
|
UErrorCode& status);
|
|
|
|
/**
|
|
* Construct a new rule with the given input, output text, and other
|
|
* attributes. A cursor position may be specified for the output text.
|
|
* @param input input string, including key and optional ante and
|
|
* post context
|
|
* @param anteContextPos offset into input to end of ante context, or -1 if
|
|
* none. Must be <= input.length() if not -1.
|
|
* @param postContextPos offset into input to start of post context, or -1
|
|
* if none. Must be <= input.length() if not -1, and must be >=
|
|
* anteContextPos.
|
|
* @param output output string
|
|
* @param cursorPosition offset into output at which cursor is located, or -1 if
|
|
* none. If less than zero, then the cursor is placed after the
|
|
* <code>output</code>; that is, -1 is equivalent to
|
|
* <code>output.length()</code>. If greater than
|
|
* <code>output.length()</code> then an exception is thrown.
|
|
*/
|
|
TransliterationRule(const UnicodeString& input,
|
|
int32_t anteContextPos, int32_t postContextPos,
|
|
const UnicodeString& outputStr,
|
|
int32_t cursorPosition,
|
|
UErrorCode& status);
|
|
|
|
/**
|
|
* Copy constructor.
|
|
*/
|
|
TransliterationRule(TransliterationRule& other);
|
|
|
|
/**
|
|
* Destructor.
|
|
*/
|
|
virtual ~TransliterationRule();
|
|
|
|
/**
|
|
* Return the position of the cursor within the output string.
|
|
* @return a value from 0 to <code>getOutput().length()</code>, inclusive.
|
|
*/
|
|
virtual int32_t getCursorPos(void) const;
|
|
|
|
/**
|
|
* Return the preceding context length. This method is needed to
|
|
* support the <code>Transliterator</code> method
|
|
* <code>getMaximumContextLength()</code>.
|
|
*/
|
|
virtual int32_t getAnteContextLength(void) const;
|
|
|
|
/**
|
|
* Internal method. Returns 8-bit index value for this rule.
|
|
* This is the low byte of the first character of the key,
|
|
* unless the first character of the key is a set. If it's a
|
|
* set, or otherwise can match multiple keys, the index value is -1.
|
|
*/
|
|
int16_t getIndexValue(const TransliterationRuleData& data) const;
|
|
|
|
/**
|
|
* Do a replacement of the input pattern with the output text in
|
|
* the given string, at the given offset. This method assumes
|
|
* that a match has already been found in the given text at the
|
|
* given position.
|
|
* @param text the text containing the substring to be replaced
|
|
* @param offset the offset into the text at which the pattern
|
|
* matches. This is the offset to the point after the ante
|
|
* context, if any, and before the match string and any post
|
|
* context.
|
|
* @param data the RuleBasedTransliterator.Data object specifying
|
|
* context for this transliterator.
|
|
* @return the change in the length of the text
|
|
*/
|
|
int32_t replace(Replaceable& text, int32_t offset,
|
|
const TransliterationRuleData& data) const;
|
|
|
|
/**
|
|
* Internal method. Returns true if this rule matches the given
|
|
* index value. The index value is an 8-bit integer, 0..255,
|
|
* representing the low byte of the first character of the key.
|
|
* It matches this rule if it matches the first character of the
|
|
* key, or if the first character of the key is a set, and the set
|
|
* contains any character with a low byte equal to the index
|
|
* value. If the rule contains only ante context, as in foo)>bar,
|
|
* then it will match any key.
|
|
*/
|
|
UBool matchesIndexValue(uint8_t v,
|
|
const TransliterationRuleData& data) const;
|
|
|
|
/**
|
|
* Return true if this rule masks another rule. If r1 masks r2 then
|
|
* r1 matches any input string that r2 matches. If r1 masks r2 and r2 masks
|
|
* r1 then r1 == r2. Examples: "a>x" masks "ab>y". "a>x" masks "a[b]>y".
|
|
* "[c]a>x" masks "[dc]a>y".
|
|
*/
|
|
virtual UBool masks(const TransliterationRule& r2) const;
|
|
|
|
/**
|
|
* Return true if this rule matches the given text.
|
|
* @param text the text, both translated and untranslated
|
|
* @param start the beginning index, inclusive; <code>0 <= start
|
|
* <= limit</code>.
|
|
* @param limit the ending index, exclusive; <code>start <= limit
|
|
* <= text.length()</code>.
|
|
* @param cursor position at which to translate next, representing offset
|
|
* into text. This value must be between <code>start</code> and
|
|
* <code>limit</code>.
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.isIn()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
*/
|
|
virtual UBool matches(const Replaceable& text,
|
|
const UTransPosition& pos,
|
|
const TransliterationRuleData& data,
|
|
const UnicodeFilter* filter) const;
|
|
|
|
/**
|
|
* Return the degree of match between this rule and the given text. The
|
|
* degree of match may be mismatch, a partial match, or a full match. A
|
|
* mismatch means at least one character of the text does not match the
|
|
* context or key. A partial match means some context and key characters
|
|
* match, but the text is not long enough to match all of them. A full
|
|
* match means all context and key characters match.
|
|
* @param text the text, both translated and untranslated
|
|
* @param start the beginning index, inclusive; <code>0 <= start
|
|
* <= limit</code>.
|
|
* @param limit the ending index, exclusive; <code>start <= limit
|
|
* <= text.length()</code>.
|
|
* @param cursor position at which to translate next, representing offset
|
|
* into text. This value must be between <code>start</code> and
|
|
* <code>limit</code>.
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.isIn()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
* @return one of <code>MISMATCH</code>, <code>PARTIAL_MATCH</code>, or
|
|
* <code>FULL_MATCH</code>.
|
|
* @see #MISMATCH
|
|
* @see #PARTIAL_MATCH
|
|
* @see #FULL_MATCH
|
|
*/
|
|
virtual int32_t getMatchDegree(const Replaceable& text,
|
|
const UTransPosition& pos,
|
|
const TransliterationRuleData& data,
|
|
const UnicodeFilter* filter) const;
|
|
|
|
/**
|
|
* Return the number of characters of the text that match this rule. If
|
|
* there is a mismatch, return -1. If the text is not long enough to match
|
|
* any characters, return 0.
|
|
* @param text the text, both translated and untranslated
|
|
* @param start the beginning index, inclusive; <code>0 <= start
|
|
* <= limit</code>.
|
|
* @param limit the ending index, exclusive; <code>start <= limit
|
|
* <= text.length()</code>.
|
|
* @param cursor position at which to translate next, representing offset
|
|
* into text. This value must be between <code>start</code> and
|
|
* <code>limit</code>.
|
|
* @param data a dictionary of variables mapping <code>Character</code>
|
|
* to <code>UnicodeSet</code>
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.isIn()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
* @return -1 if there is a mismatch, 0 if the text is not long enough to
|
|
* match any characters, otherwise the number of characters of text that
|
|
* match this rule.
|
|
*/
|
|
virtual int32_t getRegionMatchLength(const Replaceable& text,
|
|
const UTransPosition& pos,
|
|
const TransliterationRuleData& data,
|
|
const UnicodeFilter* filter) const;
|
|
|
|
/**
|
|
* Return true if the given key matches the given text. This method
|
|
* accounts for the fact that the key character may represent a character
|
|
* set. Note that the key and text characters may not be interchanged
|
|
* without altering the results.
|
|
* @param keyChar a character in the match key
|
|
* @param textChar a character in the text being transliterated
|
|
* @param data a dictionary of variables mapping <code>Character</code>
|
|
* to <code>UnicodeSet</code>
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.isIn()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
*/
|
|
virtual UBool charMatches(UChar keyChar, const Replaceable& textChar,
|
|
int32_t index,
|
|
const UTransPosition& pos,
|
|
const TransliterationRuleData& data,
|
|
const UnicodeFilter* filter) const;
|
|
|
|
/**
|
|
* Return true if the given key matches the given text. This method
|
|
* accounts for the fact that the key character may represent a character
|
|
* set. Note that the key and text characters may not be interchanged
|
|
* without altering the results.
|
|
* @param keyChar a character in the match key
|
|
* @param textChar a character in the text being transliterated
|
|
* @param data a dictionary of variables mapping <code>Character</code>
|
|
* to <code>UnicodeSet</code>
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.isIn()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
*/
|
|
//[ANCHOR] virtual UBool charMatches(UChar keyChar, UChar textChar,
|
|
//[ANCHOR] const TransliterationRuleData& data,
|
|
//[ANCHOR] const UnicodeFilter* filter) const;
|
|
|
|
private:
|
|
|
|
void init(const UnicodeString& input,
|
|
int32_t anteContextPos, int32_t postContextPos,
|
|
const UnicodeString& output,
|
|
int32_t cursorPos, int32_t cursorOffset,
|
|
int32_t* adoptedSegs,
|
|
UBool anchorStart, UBool anchorEnd,
|
|
UErrorCode& status);
|
|
|
|
};
|
|
|
|
#endif
|