scuffed-code/icu4c/source/i18n/uniset.cpp
2000-03-04 02:21:02 +00:00

1179 lines
42 KiB
C++

/*
**********************************************************************
* Copyright (C) 1999, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 10/20/99 alan Creation.
**********************************************************************
*/
#include "unicode/uniset.h"
#include "unicode/parsepos.h"
#include "symtable.h"
// N.B.: This mapping is different in ICU and Java
const UnicodeString UnicodeSet::CATEGORY_NAMES(
"CnLuLlLtLmLoMnMeMcNdNlNoZsZlZpCcCfCoCsPdPsPePcPoSmScSkSoPiPf", "");
/**
* A cache mapping character category integers, as returned by
* Unicode::getType(), to pairs strings. Entries are initially
* zero length and are filled in on demand.
*/
UnicodeString* UnicodeSet::CATEGORY_PAIRS_CACHE =
new UnicodeString[Unicode::GENERAL_TYPES_COUNT];
/**
* Delimiter string used in patterns to close a category reference:
* ":]". Example: "[:Lu:]".
*/
const UnicodeString UnicodeSet::CATEGORY_CLOSE = UNICODE_STRING(":]", 2);
/**
* Delimiter char beginning a variable reference:
* "{". Example: "{var}".
*/
const UChar UnicodeSet::VARIABLE_REF_OPEN = 0x007B /*{*/;
/**
* Delimiter char ending a variable reference:
* "}". Example: "{var}".
*/
const UChar UnicodeSet::VARIABLE_REF_CLOSE = 0x007D /*}*/;
// Define UChar constants using hex for EBCDIC compatibility
const UChar UnicodeSet::SET_OPEN = 0x005B; /*[*/
const UChar UnicodeSet::SET_CLOSE = 0x005D; /*]*/
const UChar UnicodeSet::HYPHEN = 0x002D; /*-*/
const UChar UnicodeSet::COMPLEMENT = 0x005E; /*^*/
const UChar UnicodeSet::COLON = 0x003A; /*:*/
const UChar UnicodeSet::BACKSLASH = 0x005C; /*\*/
const UChar UnicodeSet::INTERSECTION = 0x0026; /*&*/
//----------------------------------------------------------------
// Debugging and testing
//----------------------------------------------------------------
/**
* Return the representation of this set as a list of character
* ranges. Ranges are listed in ascending Unicode order. For
* example, the set [a-zA-M3] is represented as "33AMaz".
*/
const UnicodeString& UnicodeSet::getPairs(void) const {
return pairs;
}
//----------------------------------------------------------------
// Constructors &c
//----------------------------------------------------------------
/**
* Constructs an empty set.
*/
UnicodeSet::UnicodeSet() : pairs() {}
/**
* Constructs a set from the given pattern, optionally ignoring
* white space. See the class description for the syntax of the
* pattern language.
* @param pattern a string specifying what characters are in the set
* @exception <code>IllegalArgumentException</code> if the pattern
* contains a syntax error.
*/
UnicodeSet::UnicodeSet(const UnicodeString& pattern,
UErrorCode& status) : pairs() {
applyPattern(pattern, status);
}
// For internal use by RuleBasedTransliterator
UnicodeSet::UnicodeSet(const UnicodeString& pattern, ParsePosition& pos,
const SymbolTable& symbols,
UErrorCode& status) {
parse(pairs, pattern, pos, &symbols, status);
}
/**
* Constructs a set from the given Unicode character category.
* @param category an integer indicating the character category as
* returned by <code>Character.getType()</code>.
* @exception <code>IllegalArgumentException</code> if the given
* category is invalid.
*/
UnicodeSet::UnicodeSet(int8_t category, UErrorCode& status) : pairs() {
if (U_SUCCESS(status)) {
if (category < 0 || category >= Unicode::GENERAL_TYPES_COUNT) {
status = U_ILLEGAL_ARGUMENT_ERROR;
} else {
pairs = getCategoryPairs(category);
}
}
}
/**
* Constructs a set that is identical to the given UnicodeSet.
*/
UnicodeSet::UnicodeSet(const UnicodeSet& o) : pairs(o.pairs) {}
/**
* Destructs the set.
*/
UnicodeSet::~UnicodeSet() {}
/**
* Assigns this object to be a copy of another.
*/
UnicodeSet& UnicodeSet::operator=(const UnicodeSet& o) {
pairs = o.pairs;
return *this;
}
/**
* Compares the specified object with this set for equality. Returns
* <tt>true</tt> if the two sets
* have the same size, and every member of the specified set is
* contained in this set (or equivalently, every member of this set is
* contained in the specified set).
*
* @param o set to be compared for equality with this set.
* @return <tt>true</tt> if the specified set is equal to this set.
*/
bool_t UnicodeSet::operator==(const UnicodeSet& o) const {
return pairs == o.pairs;
}
/**
* Returns a copy of this object. All UnicodeFilter objects have
* to support cloning in order to allow classes using
* UnicodeFilters, such as Transliterator, to implement cloning.
*/
UnicodeFilter* UnicodeSet::clone() const {
return new UnicodeSet(*this);
}
/**
* Returns the hash code value for this set.
*
* @return the hash code value for this set.
* @see Object#hashCode()
*/
int32_t UnicodeSet::hashCode(void) const {
return pairs.hashCode();
}
//----------------------------------------------------------------
// Public API
//----------------------------------------------------------------
/**
* Modifies this set to represent the set specified by the given
* pattern, optionally ignoring white space. See the class
* description for the syntax of the pattern language.
* @param pattern a string specifying what characters are in the set
* @param ignoreSpaces if <code>true</code>, all spaces in the
* pattern are ignored. Spaces are those characters for which
* <code>Character.isSpaceChar()</code> is <code>true</code>.
* Characters preceded by '\\' are escaped, losing any special
* meaning they otherwise have. Spaces may be included by
* escaping them.
* @exception <code>IllegalArgumentException</code> if the pattern
* contains a syntax error.
*/
void UnicodeSet::applyPattern(const UnicodeString& pattern,
UErrorCode& status) {
if (U_FAILURE(status)) {
return;
}
ParsePosition pos(0);
parse(pairs, pattern, pos, NULL, status);
// Skip over trailing whitespace
int32_t i = pos.getIndex();
int32_t n = pattern.length();
while (i<n && Unicode::isWhitespace(pattern.charAt(i))) {
++i;
}
if (i != n) {
status = U_ILLEGAL_ARGUMENT_ERROR;
}
}
/**
* Returns a string representation of this set. If the result of
* calling this function is passed to a UnicodeSet constructor, it
* will produce another set that is equal to this one.
*/
UnicodeString& UnicodeSet::toPattern(UnicodeString& result) const {
result.remove().append(SET_OPEN);
// iterate through the ranges in the UnicodeSet
for (int32_t i=0; i<pairs.length(); i+=2) {
// for a range with the same beginning and ending point,
// output that character, otherwise, output the start and
// end points of the range separated by a dash
result.append(pairs.charAt(i));
if (pairs.charAt(i) != pairs.charAt(i+1)) {
result.append(HYPHEN).append(pairs.charAt(i+1));
}
}
return result.append(SET_CLOSE);
}
/**
* Returns the number of elements in this set (its cardinality),
* <em>n</em>, where <code>0 <= </code><em>n</em><code> <= 65536</code>.
*
* @return the number of elements in this set (its cardinality).
*/
int32_t UnicodeSet::size(void) const {
int32_t n = 0;
for (int32_t i=0; i<pairs.length(); i+=2) {
n += pairs.charAt(i+1) - pairs.charAt(i) + 1;
}
return n;
}
/**
* Returns <tt>true</tt> if this set contains no elements.
*
* @return <tt>true</tt> if this set contains no elements.
*/
bool_t UnicodeSet::isEmpty(void) const {
return pairs.length() == 0;
}
/**
* Returns <tt>true</tt> if this set contains the specified range
* of chars.
*
* @return <tt>true</tt> if this set contains the specified range
* of chars.
*/
bool_t UnicodeSet::contains(UChar first, UChar last) const {
// Set i to the end of the smallest range such that its end
// point >= last, or pairs.length() if no such range exists.
int32_t i = 1;
while (i<pairs.length() && last>pairs.charAt(i)) i+=2;
return i<pairs.length() && first>=pairs.charAt(i-1);
}
/**
* Returns <tt>true</tt> if this set contains the specified char.
*
* @return <tt>true</tt> if this set contains the specified char.
*/
bool_t UnicodeSet::contains(UChar c) const {
return contains(c, c);
}
/**
* Returns <tt>true</tt> if this set contains any character whose low byte
* is the given value. This is used by <tt>RuleBasedTransliterator</tt> for
* indexing.
*/
bool_t UnicodeSet::containsIndexValue(uint8_t v) const {
/* The index value v, in the range [0,255], is contained in this set if
* it is contained in any pair of this set. Pairs either have the high
* bytes equal, or unequal. If the high bytes are equal, then we have
* aaxx..aayy, where aa is the high byte. Then v is contained if xx <=
* v <= yy. If the high bytes are unequal we have aaxx..bbyy, bb>aa.
* Then v is contained if xx <= v || v <= yy. (This is identical to the
* time zone month containment logic.)
*/
for (int32_t i=0; i<pairs.length(); i+=2) {
UChar low = pairs.charAt(i);
UChar high = pairs.charAt(i+1);
if ((low & 0xFF00) == (high & 0xFF00)) {
if (uint8_t(low) <= v && v <= uint8_t(high)) {
return TRUE;
}
} else if (uint8_t(low) <= v || v <= uint8_t(high)) {
return TRUE;
}
}
return FALSE;
}
/**
* Adds the specified range to this set if it is not already
* present. If this set already contains the specified range,
* the call leaves this set unchanged. If <code>last > first</code>
* then an empty range is added, leaving the set unchanged.
*
* @param first first character, inclusive, of range to be added
* to this set.
* @param last last character, inclusive, of range to be added
* to this set.
*/
void UnicodeSet::add(UChar first, UChar last) {
if (first <= last) {
addPair(pairs, first, last);
}
}
/**
* Adds the specified character to this set if it is not already
* present. If this set already contains the specified character,
* the call leaves this set unchanged.
*/
void UnicodeSet::add(UChar c) {
add(c, c);
}
/**
* Removes the specified range from this set if it is present.
* The set will not contain the specified range once the call
* returns. If <code>last > first</code> then an empty range is
* removed, leaving the set unchanged.
*
* @param first first character, inclusive, of range to be removed
* from this set.
* @param last last character, inclusive, of range to be removed
* from this set.
*/
void UnicodeSet::remove(UChar first, UChar last) {
if (first <= last) {
removePair(pairs, first, last);
}
}
/**
* Removes the specified character from this set if it is present.
* The set will not contain the specified range once the call
* returns.
*/
void UnicodeSet::remove(UChar c) {
remove(c, c);
}
/**
* Returns <tt>true</tt> if the specified set is a <i>subset</i>
* of this set.
*
* @param c set to be checked for containment in this set.
* @return <tt>true</tt> if this set contains all of the elements of the
* specified set.
*/
bool_t UnicodeSet::containsAll(const UnicodeSet& c) const {
// The specified set is a subset if all of its pairs are contained
// in this set.
int32_t i = 1;
for (int32_t j=0; j<c.pairs.length(); j+=2) {
UChar last = c.pairs.charAt(j+1);
// Set i to the end of the smallest range such that its
// end point >= last, or pairs.length() if no such range
// exists.
while (i<pairs.length() && last>pairs.charAt(i)) i+=2;
if (i>pairs.length() || c.pairs.charAt(j) < pairs.charAt(i-1)) {
return FALSE;
}
}
return TRUE;
}
/**
* Adds all of the elements in the specified set to this set if
* they're not already present. This operation effectively
* modifies this set so that its value is the <i>union</i> of the two
* sets. The behavior of this operation is unspecified if the specified
* collection is modified while the operation is in progress.
*
* @param c set whose elements are to be added to this set.
* @see #add(char, char)
*/
void UnicodeSet::addAll(const UnicodeSet& c) {
doUnion(pairs, c.pairs);
}
/**
* Retains only the elements in this set that are contained in the
* specified set. In other words, removes from this set all of
* its elements that are not contained in the specified set. This
* operation effectively modifies this set so that its value is
* the <i>intersection</i> of the two sets.
*
* @param c set that defines which elements this set will retain.
*/
void UnicodeSet::retainAll(const UnicodeSet& c) {
doIntersection(pairs, c.pairs);
}
/**
* Removes from this set all of its elements that are contained in the
* specified set. This operation effectively modifies this
* set so that its value is the <i>asymmetric set difference</i> of
* the two sets.
*
* @param c set that defines which elements will be removed from
* this set.
*/
void UnicodeSet::removeAll(const UnicodeSet& c) {
doDifference(pairs, c.pairs);
}
/**
* Inverts this set. This operation modifies this set so that
* its value is its complement. This is equivalent to the pseudo code:
* <code>this = new UnicodeSet("[\u0000-\uFFFF]").removeAll(this)</code>.
*/
void UnicodeSet::complement(void) {
doComplement(pairs);
}
/**
* Removes all of the elements from this set. This set will be
* empty after this call returns.
*/
void UnicodeSet::clear(void) {
pairs.remove();
}
//----------------------------------------------------------------
// Implementation: Pattern parsing
//----------------------------------------------------------------
/**
* Parses the given pattern, starting at the given position. The
* character at pattern.charAt(pos.getIndex()) must be '[', or the
* parse fails. Parsing continues until the corresponding closing
* ']'. If a syntax error is encountered between the opening and
* closing brace, the parse fails. Upon return from a U_SUCCESSful
* parse, the ParsePosition is updated to point to the character
* following the closing ']', and a StringBuffer containing a
* pairs list for the parsed pattern is returned. This method calls
* itself recursively to parse embedded subpatterns.
*
* @param pattern the string containing the pattern to be parsed.
* The portion of the string from pos.getIndex(), which must be a
* '[', to the corresponding closing ']', is parsed.
* @param pos upon entry, the position at which to being parsing.
* The character at pattern.charAt(pos.getIndex()) must be a '['.
* Upon return from a U_SUCCESSful parse, pos.getIndex() is either
* the character after the closing ']' of the parsed pattern, or
* pattern.length() if the closing ']' is the last character of
* the pattern string.
* @return a StringBuffer containing a pairs list for the parsed
* substring of <code>pattern</code>
* @exception IllegalArgumentException if the parse fails.
*/
UnicodeString& UnicodeSet::parse(UnicodeString& pairsBuf /*result*/,
const UnicodeString& pattern,
ParsePosition& pos,
const SymbolTable* symbols,
UErrorCode& status) {
if (U_FAILURE(status)) {
return pairsBuf;
}
bool_t invert = FALSE;
pairsBuf.remove();
int32_t lastChar = -1; // This is either a char (0..FFFF) or -1
UChar lastOp = 0;
/* This loop iterates over the characters in the pattern. We start at
* the position specified by pos. We exit the loop when either a
* matching closing ']' is seen, or we read all characters of the
* pattern. In the latter case an error will be thrown.
*/
/* Pattern syntax:
* pat := '[' '^'? elem* ']'
* elem := a | a '-' a | set | set op set
* set := pat | (a set variable)
* op := '&' | '-'
* a := (a character, possibly defined by a var)
*/
// mode 0: No chars parsed yet; next must be '['
// mode 1: '[' seen; if next is '^' or ':' then special
// mode 2: '[' '^'? seen; parse pattern and close with ']'
// mode 3: '[:' seen; parse category and close with ':]'
int8_t mode = 0;
int32_t openPos = 0; // offset to opening '['
int32_t i = pos.getIndex();
int32_t limit = pattern.length();
UnicodeString nestedAux;
UnicodeString* nestedPairs;
UnicodeString scratch;
for (; i<limit; ++i) {
/* If the next element is a single character, c will be set to it,
* and nestedPairs will be null. In this case isLiteral indicates
* whether the character should assume special meaning if it has
* one. If the next element is a nested set, either via a variable
* reference, or via an embedded "[..]" or "[:..:]" pattern, then
* nestedPairs will be set to the pairs list for the nested set, and
* c's value should be ignored.
*/
UChar c = pattern.charAt(i);
nestedPairs = NULL;
bool_t isLiteral = FALSE;
// Ignore whitespace. This is not Unicode whitespace, but Java
// whitespace, a subset of Unicode whitespace.
if (Unicode::isWhitespace(c)) {
continue;
}
// Parse the opening '[' and optional following '^'
switch (mode) {
case 0:
if (c == SET_OPEN) {
mode = 1; // Next look for '^'
openPos = i;
continue;
} else {
// throw new IllegalArgumentException("Missing opening '['");
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
case 1:
mode = 2;
switch (c) {
case COMPLEMENT:
invert = TRUE;
continue; // Back to top to fetch next character
case COLON:
if (i == openPos+1) {
// '[:' cannot have whitespace in it
--i;
c = SET_OPEN;
mode = 3;
// Fall through and parse category normally
}
break; // Fall through
case HYPHEN:
isLiteral = TRUE; // Treat leading '-' as a literal
break; // Fall through
}
// else fall through and parse this character normally
}
// After opening matter is parsed ("[", "[^", or "[:"), the mode
// will be 2 if we want a closing ']', or 3 if we should parse a
// category and close with ":]".
/* Handle escapes. If a character is escaped, then it assumes its
* literal value. This is true for all characters, both special
* characters and characters with no special meaning. We also
* interpret '\\uxxxx' Unicode escapes here (as literals).
*/
if (c == BACKSLASH) {
++i;
if (i < pattern.length()) {
c = pattern.charAt(i);
isLiteral = TRUE;
if (c == 0x0075 /*u*/) {
if ((i+4) >= pattern.length()) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
c = (UChar)0x0000;
for (int32_t j=(++i)+4; i<j; ++i) { // [sic]
int32_t digit = Unicode::digit(pattern.charAt(i), 16);
if (digit<0) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
c = (UChar) ((c << 4) | digit);
}
--i; // Move i back to last parsed character
}
} else {
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
}
/* Parse variable references. These are treated as literals. If a
* variable refers to a UnicodeSet, nestedPairs is assigned here.
* Variable names are only parsed if varNameToChar is not null.
* Set variables are only looked up if varCharToSet is not null.
*/
else if (symbols != NULL && !isLiteral && c == VARIABLE_REF_OPEN) {
++i;
int32_t j = pattern.indexOf(VARIABLE_REF_CLOSE, i);
UnicodeSet* set = NULL;
if (i == j || j < 0) { // empty or unterminated
// throw new IllegalArgumentException("Illegal variable reference");
status = U_ILLEGAL_ARGUMENT_ERROR;
} else {
scratch.truncate(0);
pattern.extractBetween(i, j, scratch);
symbols->lookup(scratch, c, set, status);
}
if (U_FAILURE(status)) {
// Either the reference was ill-formed (empty name, or no
// closing '}', or the specified name is not defined.
return pairsBuf;
}
isLiteral = TRUE;
if (set != NULL) {
nestedPairs = &set->pairs;
}
i = j; // Make i point to '}'
}
/* An opening bracket indicates the first bracket of a nested
* subpattern, either a normal pattern or a category pattern. We
* recognize these here and set nestedPairs accordingly.
*/
else if (!isLiteral && c == SET_OPEN) {
// Handle "[:...:]", representing a character category
UChar d = charAfter(pattern, i);
if (d == COLON) {
i += 2;
int32_t j = pattern.indexOf(CATEGORY_CLOSE, i);
if (j < 0) {
// throw new IllegalArgumentException("Missing \":]\"");
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
scratch.truncate(0);
pattern.extractBetween(i, j, scratch);
nestedPairs = &getCategoryPairs(nestedAux, scratch, status);
if (U_FAILURE(status)) {
return pairsBuf;
}
i = j+1; // Make i point to ']' in ":]"
if (mode == 3) {
// Entire pattern is a category; leave parse loop
pairsBuf.append(*nestedPairs);
break;
}
} else {
// Recurse to get the pairs for this nested set.
pos.setIndex(i);
nestedPairs = &parse(nestedAux, pattern, pos, symbols, status);
if (U_FAILURE(status)) {
return pairsBuf;
}
i = pos.getIndex() - 1; // - 1 to point at ']'
}
}
/* At this point we have either a character c, or a nested set. If
* we have encountered a nested set, either embedded in the pattern,
* or as a variable, we have a non-null nestedPairs, and c should be
* ignored. Otherwise c is the current character, and isLiteral
* indicates whether it is an escaped literal (or variable) or a
* normal unescaped character. Unescaped characters '-', '&', and
* ']' have special meanings.
*/
if (nestedPairs != NULL) {
if (lastChar >= 0) {
if (lastOp != 0) {
// throw new IllegalArgumentException("Illegal rhs for " + lastChar + lastOp);
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
addPair(pairsBuf, (UChar)lastChar, (UChar)lastChar);
lastChar = -1;
}
switch (lastOp) {
case HYPHEN:
doDifference(pairsBuf, *nestedPairs);
break;
case INTERSECTION:
doIntersection(pairsBuf, *nestedPairs);
break;
case 0:
doUnion(pairsBuf, *nestedPairs);
break;
}
lastOp = 0;
} else if (!isLiteral && c == SET_CLOSE) {
// Final closing delimiter. This is the only way we leave this
// loop if the pattern is well-formed.
break;
} else if (lastOp == 0 && !isLiteral && (c == HYPHEN || c == INTERSECTION)) {
lastOp = c;
} else if (lastOp == HYPHEN) {
addPair(pairsBuf, (UChar)lastChar, c);
lastOp = 0;
lastChar = -1;
} else if (lastOp != 0) {
// We have <set>&<char> or <char>&<char>
// throw new IllegalArgumentException("Unquoted " + lastOp);
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
} else {
if (lastChar >= 0) {
// We have <char><char>
addPair(pairsBuf, (UChar)lastChar, (UChar)lastChar);
}
lastChar = c;
}
}
// Handle unprocessed stuff preceding the closing ']'
if (lastOp == HYPHEN) {
// Trailing '-' is treated as literal
addPair(pairsBuf, lastOp, lastOp);
} else if (lastOp == INTERSECTION) {
// throw new IllegalArgumentException("Unquoted trailing " + lastOp);
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
if (lastChar >= 0) {
addPair(pairsBuf, (UChar)lastChar, (UChar)lastChar);
}
/**
* If we saw a '^' after the initial '[' of this pattern, then perform
* the complement. (Inversion after '[:' is handled elsewhere.)
*/
if (invert) {
doComplement(pairsBuf);
}
/**
* i indexes the last character we parsed or is pattern.length(). In
* the latter case, we have run off the end without finding a closing
* ']'. Otherwise, we know i < pattern.length(), and we set the
* ParsePosition to the next character to be parsed.
*/
if (i == limit) {
// throw new IllegalArgumentException("Missing ']'");
status = U_ILLEGAL_ARGUMENT_ERROR;
return pairsBuf;
}
pos.setIndex(i+1);
return pairsBuf;
}
//----------------------------------------------------------------
// Implementation: Efficient in-place union & difference
//----------------------------------------------------------------
/**
* Performs a union operation: adds the range 'c'-'d' to the given
* pairs list. The pairs list is modified in place. The result
* is normalized (in order and as short as possible). For
* example, addPair("am", 'l', 'q') => "aq". addPair("ampz", 'n',
* 'o') => "az".
*/
void UnicodeSet::addPair(UnicodeString& pairs, UChar c, UChar d) {
UChar a = 0;
UChar b = 0;
for (int32_t i=0; i<pairs.length(); i+=2) {
UChar e = pairs.charAt(i);
UChar f = pairs.charAt(i+1);
if (e <= (d+1) && c <= (f+1)) {
// Merge with this range
f = (UChar) uprv_max(d, f);
// Check to see if we need to merge with the
// subsequent range also. This happens if we have
// "abdf" and are merging in "cc". We only need to
// check on the right side -- never on the left.
if ((i+2) < pairs.length() &&
pairs.charAt(i+2) == (f+1)) {
f = pairs.charAt(i+3);
pairs.remove(i+2, 2);
}
pairs.setCharAt(i, (UChar) uprv_min(c, e));
pairs.setCharAt(i+1, f);
return;
} else if ((b+1) < c && (d+1) < e) {
// Insert before this range c, then d
pairs.insert(i, d); // d gets moved to i+1 by next insert
pairs.insert(i, c);
return;
}
a = e;
b = f;
}
// If nothing else, fall through and append this new range to
// the end.
pairs.append(c).append(d);
}
/**
* Performs an asymmetric difference: removes the range 'c'-'d'
* from the pairs list. The pairs list is modified in place. The
* result is normalized (in order and as short as possible). For
* example, removePair("am", 'l', 'q') => "ak".
* removePair("ampz", 'l', 'q') => "akrz".
*/
void UnicodeSet::removePair(UnicodeString& pairs, UChar c, UChar d) {
// Iterate over pairs until we find a pair that overlaps
// with the given range.
for (int32_t i=0; i<pairs.length(); i+=2) {
UChar b = pairs.charAt(i+1);
if (b < c) {
// Range at i is entirely before the given range,
// since we have a-b < c-d. No overlap yet...keep
// iterating.
continue;
}
UChar a = pairs.charAt(i);
if (d < a) {
// Range at i is entirely after the given range; c-d <
// a-b. Since ranges are in order, nothing else will
// overlap.
break;
}
// Once we get here, we know c <= b and d >= a.
// rangeEdited is set to true if we have modified the
// range a-b (the range at i) in place.
bool_t rangeEdited = FALSE;
if (c > a) {
// If c is after a and before b, then we have overlap
// of this sort: a--c==b--d or a--c==d--b, where a-b
// and c-d are the ranges of interest. We need to
// add the range a,c-1.
pairs.setCharAt(i+1, (UChar)(c-1));
// i is already a
rangeEdited = TRUE;
}
if (d < b) {
// If d is after a and before b, we overlap like this:
// c--a==d--b or a--c==d--b, where a-b is the range at
// i and c-d is the range being removed. We need to
// add the range d+1,b.
if (rangeEdited) {
// Insert {d+1, b}
pairs.insert(i+2, b); // b moves to i+3 by next insert:
pairs.insert(i+2, (UChar)(d+1));
i += 2;
} else {
pairs.setCharAt(i, (UChar)(d+1));
// i+1 is already b
rangeEdited = TRUE;
}
}
if (!rangeEdited) {
// If we didn't add any ranges, that means the entire
// range a-b must be deleted, since we have
// c--a==b--d.
pairs.remove(i, 2);
i -= 2;
}
}
}
//----------------------------------------------------------------
// Implementation: Fundamental operators
//----------------------------------------------------------------
/**
* Changes the pairs list to represent the complement of the set it
* currently represents. The pairs list will be normalized (in
* order and in shortest possible form) if the original pairs list
* was normalized.
*/
void UnicodeSet::doComplement(UnicodeString& pairs) {
if (pairs.length() == 0) {
pairs.append((UChar)0x0000).append((UChar)0xffff);
return;
}
// Change each end to a start and each start to an end of the
// gaps between the ranges. That is, 3-7 9-12 becomes x-2 8-8
// 13-x, where 'x' represents a range that must now be fixed
// up.
for (int32_t i=0; i<pairs.length(); i+=2) {
pairs.setCharAt(i, (UChar) (pairs.charAt(i) - 1));
pairs.setCharAt(i+1, (UChar) (pairs.charAt(i+1) + 1));
}
// Fix up the initial range, either by adding a start point of
// U+0000, or by deleting the range altogether, if the
// original range was U+0000 - x.
if (pairs.charAt(0) == (UChar)0xFFFF) {
pairs.remove(0, 1);
} else {
pairs.insert(0, (UChar)0x0000);
}
// Fix up the final range, either by adding an end point of
// U+FFFF, or by deleting the range altogether, if the
// original range was x - U+FFFF.
if (pairs.charAt(pairs.length() - 1) == (UChar)0x0000) {
pairs.remove(pairs.length() - 1);
} else {
pairs.append((UChar)0xFFFF);
}
}
/**
* Given two pairs lists, changes the first in place to represent
* the union of the two sets.
*/
void UnicodeSet::doUnion(UnicodeString& c1, const UnicodeString& c2) {
UnicodeString result;
int32_t i = 0;
int32_t j = 0;
// consider all the characters in both strings
while (i < c1.length() && j < c2.length()) {
UChar ub;
// the first character in the result is the lower of the
// starting characters of the two strings, and "ub" gets
// set to the upper bound of that range
if (c1.charAt(i) < c2.charAt(j)) {
result.append(c1.charAt(i));
ub = c1.charAt(++i);
}
else {
result.append(c2.charAt(j));
ub = c2.charAt(++j);
}
// for as long as one of our two pointers is pointing to a range's
// end point, or i is pointing to a character that is less than
// "ub" plus one (the "plus one" stitches touching ranges together)...
while (i % 2 == 1 || j % 2 == 1 || (i < c1.length() && c1.charAt(i)
<= ub + 1)) {
// advance i to the first character that is greater than
// "ub" plus one
while (i < c1.length() && c1.charAt(i) <= ub + 1)
++i;
// if i points to the endpoint of a range, update "ub"
// to that character, or if i points to the start of
// a range and the endpoint of the preceding range is
// greater than "ub", update "up" to _that_ character
if (i % 2 == 1)
ub = c1.charAt(i);
else if (i > 0 && c1.charAt(i - 1) > ub)
ub = c1.charAt(i - 1);
// now advance j to the first character that is greater
// that "ub" plus one
while (j < c2.length() && c2.charAt(j) <= ub + 1)
++j;
// if j points to the endpoint of a range, update "ub"
// to that character, or if j points to the start of
// a range and the endpoint of the preceding range is
// greater than "ub", update "up" to _that_ character
if (j % 2 == 1)
ub = c2.charAt(j);
else if (j > 0 && c2.charAt(j - 1) > ub)
ub = c2.charAt(j - 1);
}
// when we finally fall out of this loop, we will have stitched
// together a series of ranges that overlap or touch, i and j
// will both point to starting points of ranges, and "ub" will
// be the endpoint of the range we're working on. Write "ub"
// to the result
result.append(ub);
// loop back around to create the next range in the result
}
// we fall out to here when we've exhausted all the characters in
// one of the operands. We can append all of the remaining characters
// in the other operand without doing any extra work.
if (i < c1.length())
result.append(c1, i, LONG_MAX);
if (j < c2.length())
result.append(c2, j, LONG_MAX);
c1 = result;
}
/**
* Given two pairs lists, changes the first in place to represent
* the asymmetric difference of the two sets.
*/
void UnicodeSet::doDifference(UnicodeString& pairs, const UnicodeString& pairs2) {
UnicodeString p2(pairs2);
doComplement(p2);
doIntersection(pairs, p2);
}
/**
* Given two pairs lists, changes the first in place to represent
* the intersection of the two sets.
*/
void UnicodeSet::doIntersection(UnicodeString& c1, const UnicodeString& c2) {
UnicodeString result;
int32_t i = 0;
int32_t j = 0;
int32_t oldI;
int32_t oldJ;
// iterate until we've exhausted one of the operands
while (i < c1.length() && j < c2.length()) {
// advance j until it points to a character that is larger than
// the one i points to. If this is the beginning of a one-
// character range, advance j to point to the end
if (i < c1.length() && i % 2 == 0) {
while (j < c2.length() && c2.charAt(j) < c1.charAt(i))
++j;
if (j < c2.length() && j % 2 == 0 && c2.charAt(j) == c1.charAt(i))
++j;
}
// if j points to the endpoint of a range, save the current
// value of i, then advance i until it reaches a character
// which is larger than the character pointed at
// by j. All of the characters we've advanced over (except
// the one currently pointed to by i) are added to the result
oldI = i;
while (j % 2 == 1 && i < c1.length() && c1.charAt(i) <= c2.charAt(j))
++i;
result.append(c1, oldI, i-oldI);
// if i points to the endpoint of a range, save the current
// value of j, then advance j until it reaches a character
// which is larger than the character pointed at
// by i. All of the characters we've advanced over (except
// the one currently pointed to by i) are added to the result
oldJ = j;
while (i % 2 == 1 && j < c2.length() && c2.charAt(j) <= c1.charAt(i))
++j;
result.append(c2, oldJ, j-oldJ);
// advance i until it points to a character larger than j
// If it points at the beginning of a one-character range,
// advance it to the end of that range
if (j < c2.length() && j % 2 == 0) {
while (i < c1.length() && c1.charAt(i) < c2.charAt(j))
++i;
if (i < c1.length() && i % 2 == 0 && c2.charAt(j) == c1.charAt(i))
++i;
}
}
c1 = result;
}
//----------------------------------------------------------------
// Implementation: Generation of pairs for Unicode categories
//----------------------------------------------------------------
/**
* Returns a pairs string for the given category, given its name.
* The category name must be either a two-letter name, such as
* "Lu", or a one letter name, such as "L". One-letter names
* indicate the logical union of all two-letter names that start
* with that letter. Case is significant. If the name starts
* with the character '^' then the complement of the given
* character set is returned.
*
* Although individual categories such as "Lu" are cached, we do
* not currently cache single-letter categories such as "L" or
* complements such as "^Lu" or "^L". It would be easy to cache
* these as well in a hashtable should the need arise.
*/
UnicodeString& UnicodeSet::getCategoryPairs(UnicodeString& result,
const UnicodeString& catName,
UErrorCode& status) {
if (U_FAILURE(status)) {
return result;
}
// The temporary cat is only really needed if invert is true.
// TO DO: Allocate cat on the heap only if needed.
UnicodeString cat(catName);
bool_t invert = (catName.length() > 1 &&
catName.charAt(0) == COMPLEMENT);
if (invert) {
cat.remove(0, 1);
}
result.remove();
// if we have two characters, search the category map for that
// code and either construct and return a UnicodeSet from the
// data in the category map or throw an exception
if (cat.length() == 2) {
int32_t i = CATEGORY_NAMES.indexOf(cat);
if (i>=0 && i%2==0) {
i /= 2;
result = getCategoryPairs((int8_t)i);
if (!invert) {
return result;
}
}
} else if (cat.length() == 1) {
// if we have one character, search the category map for
// codes beginning with that letter, and union together
// all of the matching sets that we find (or throw an
// exception if there are no matches)
for (int32_t i=0; i<Unicode::GENERAL_TYPES_COUNT; ++i) {
if (CATEGORY_NAMES.charAt(2*i) == cat.charAt(0)) {
const UnicodeString& pairs = getCategoryPairs((int8_t)i);
if (result.length() == 0) {
result = pairs;
} else {
doUnion(result, pairs);
}
}
}
}
if (result.length() == 0) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return result;
}
if (invert) {
doComplement(result);
}
return result;
}
/**
* Returns a pairs string for the given category. This string is
* cached and returned again if this method is called again with
* the same parameter.
*/
const UnicodeString& UnicodeSet::getCategoryPairs(int8_t cat) {
// In order to tell what cache entries are empty, we assume
// every category specifies at least one character. Thus
// pair lists in the cache that are empty are uninitialized.
if (CATEGORY_PAIRS_CACHE[cat].length() == 0) {
// Walk through all Unicode characters, noting the start
// and end of each range for which Character.getType(c)
// returns the given category integer. Since we are
// iterating in order, we can simply append the resulting
// ranges to the pairs string.
UnicodeString& pairs = CATEGORY_PAIRS_CACHE[cat];
int32_t first = -1;
int32_t last = -2;
for (int32_t i=0; i<=0xFFFF; ++i) {
if (Unicode::getType((UChar)i) == cat) {
if ((last+1) == i) {
last = i;
} else {
if (first >= 0) {
pairs.append((UChar)first).append((UChar)last);
}
first = last = i;
}
}
}
if (first >= 0) {
pairs.append((UChar)first).append((UChar)last);
}
}
return CATEGORY_PAIRS_CACHE[cat];
}
//----------------------------------------------------------------
// Implementation: Utility methods
//----------------------------------------------------------------
/**
* Returns the character after the given position, or '\uFFFF' if
* there is none.
*/
UChar UnicodeSet::charAfter(const UnicodeString& str, int32_t i) {
return ((++i) < str.length()) ? str.charAt(i) : (UChar)0xFFFF;
}