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gecko-dev/intl/icu/source/common/util.cpp

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/*
**********************************************************************
* Copyright (c) 2001-2011, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/19/2001 aliu Creation.
**********************************************************************
*/
#include "unicode/unimatch.h"
#include "unicode/utf16.h"
#include "patternprops.h"
#include "util.h"
// Define UChar constants using hex for EBCDIC compatibility
static const UChar BACKSLASH = 0x005C; /*\*/
static const UChar UPPER_U = 0x0055; /*U*/
static const UChar LOWER_U = 0x0075; /*u*/
static const UChar APOSTROPHE = 0x0027; // '\''
static const UChar SPACE = 0x0020; // ' '
// "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
static const UChar DIGITS[] = {
48,49,50,51,52,53,54,55,56,57,
65,66,67,68,69,70,71,72,73,74,
75,76,77,78,79,80,81,82,83,84,
85,86,87,88,89,90
};
U_NAMESPACE_BEGIN
UnicodeString& ICU_Utility::appendNumber(UnicodeString& result, int32_t n,
int32_t radix, int32_t minDigits) {
if (radix < 2 || radix > 36) {
// Bogus radix
return result.append((UChar)63/*?*/);
}
// Handle negatives
if (n < 0) {
n = -n;
result.append((UChar)45/*-*/);
}
// First determine the number of digits
int32_t nn = n;
int32_t r = 1;
while (nn >= radix) {
nn /= radix;
r *= radix;
--minDigits;
}
// Now generate the digits
while (--minDigits > 0) {
result.append(DIGITS[0]);
}
while (r > 0) {
int32_t digit = n / r;
result.append(DIGITS[digit]);
n -= digit * r;
r /= radix;
}
return result;
}
/**
* Return true if the character is NOT printable ASCII.
*/
UBool ICU_Utility::isUnprintable(UChar32 c) {
return !(c >= 0x20 && c <= 0x7E);
}
/**
* Escape unprintable characters using \uxxxx notation for U+0000 to
* U+FFFF and \Uxxxxxxxx for U+10000 and above. If the character is
* printable ASCII, then do nothing and return FALSE. Otherwise,
* append the escaped notation and return TRUE.
*/
UBool ICU_Utility::escapeUnprintable(UnicodeString& result, UChar32 c) {
if (isUnprintable(c)) {
result.append(BACKSLASH);
if (c & ~0xFFFF) {
result.append(UPPER_U);
result.append(DIGITS[0xF&(c>>28)]);
result.append(DIGITS[0xF&(c>>24)]);
result.append(DIGITS[0xF&(c>>20)]);
result.append(DIGITS[0xF&(c>>16)]);
} else {
result.append(LOWER_U);
}
result.append(DIGITS[0xF&(c>>12)]);
result.append(DIGITS[0xF&(c>>8)]);
result.append(DIGITS[0xF&(c>>4)]);
result.append(DIGITS[0xF&c]);
return TRUE;
}
return FALSE;
}
/**
* Returns the index of a character, ignoring quoted text.
* For example, in the string "abc'hide'h", the 'h' in "hide" will not be
* found by a search for 'h'.
*/
// FOR FUTURE USE. DISABLE FOR NOW for coverage reasons.
/*
int32_t ICU_Utility::quotedIndexOf(const UnicodeString& text,
int32_t start, int32_t limit,
UChar charToFind) {
for (int32_t i=start; i<limit; ++i) {
UChar c = text.charAt(i);
if (c == BACKSLASH) {
++i;
} else if (c == APOSTROPHE) {
while (++i < limit
&& text.charAt(i) != APOSTROPHE) {}
} else if (c == charToFind) {
return i;
}
}
return -1;
}
*/
/**
* Skip over a sequence of zero or more white space characters at pos.
* @param advance if true, advance pos to the first non-white-space
* character at or after pos, or str.length(), if there is none.
* Otherwise leave pos unchanged.
* @return the index of the first non-white-space character at or
* after pos, or str.length(), if there is none.
*/
int32_t ICU_Utility::skipWhitespace(const UnicodeString& str, int32_t& pos,
UBool advance) {
int32_t p = pos;
const UChar* s = str.getBuffer();
p = (int32_t)(PatternProps::skipWhiteSpace(s + p, str.length() - p) - s);
if (advance) {
pos = p;
}
return p;
}
/**
* Skip over Pattern_White_Space in a Replaceable.
* Skipping may be done in the forward or
* reverse direction. In either case, the leftmost index will be
* inclusive, and the rightmost index will be exclusive. That is,
* given a range defined as [start, limit), the call
* skipWhitespace(text, start, limit) will advance start past leading
* whitespace, whereas the call skipWhitespace(text, limit, start),
* will back up limit past trailing whitespace.
* @param text the text to be analyzed
* @param pos either the start or limit of a range of 'text', to skip
* leading or trailing whitespace, respectively
* @param stop either the limit or start of a range of 'text', to skip
* leading or trailing whitespace, respectively
* @return the new start or limit, depending on what was passed in to
* 'pos'
*/
//?FOR FUTURE USE. DISABLE FOR NOW for coverage reasons.
//?int32_t ICU_Utility::skipWhitespace(const Replaceable& text,
//? int32_t pos, int32_t stop) {
//? UChar32 c;
//? UBool isForward = (stop >= pos);
//?
//? if (!isForward) {
//? --pos; // pos is a limit, so back up by one
//? }
//?
//? while (pos != stop &&
//? PatternProps::isWhiteSpace(c = text.char32At(pos))) {
//? if (isForward) {
//? pos += U16_LENGTH(c);
//? } else {
//? pos -= U16_LENGTH(c);
//? }
//? }
//?
//? if (!isForward) {
//? ++pos; // make pos back into a limit
//? }
//?
//? return pos;
//?}
/**
* Parse a single non-whitespace character 'ch', optionally
* preceded by whitespace.
* @param id the string to be parsed
* @param pos INPUT-OUTPUT parameter. On input, pos[0] is the
* offset of the first character to be parsed. On output, pos[0]
* is the index after the last parsed character. If the parse
* fails, pos[0] will be unchanged.
* @param ch the non-whitespace character to be parsed.
* @return true if 'ch' is seen preceded by zero or more
* whitespace characters.
*/
UBool ICU_Utility::parseChar(const UnicodeString& id, int32_t& pos, UChar ch) {
int32_t start = pos;
skipWhitespace(id, pos, TRUE);
if (pos == id.length() ||
id.charAt(pos) != ch) {
pos = start;
return FALSE;
}
++pos;
return TRUE;
}
/**
* Parse a pattern string within the given Replaceable and a parsing
* pattern. Characters are matched literally and case-sensitively
* except for the following special characters:
*
* ~ zero or more Pattern_White_Space chars
*
* If end of pattern is reached with all matches along the way,
* pos is advanced to the first unparsed index and returned.
* Otherwise -1 is returned.
* @param pat pattern that controls parsing
* @param text text to be parsed, starting at index
* @param index offset to first character to parse
* @param limit offset after last character to parse
* @return index after last parsed character, or -1 on parse failure.
*/
int32_t ICU_Utility::parsePattern(const UnicodeString& pat,
const Replaceable& text,
int32_t index,
int32_t limit) {
int32_t ipat = 0;
// empty pattern matches immediately
if (ipat == pat.length()) {
return index;
}
UChar32 cpat = pat.char32At(ipat);
while (index < limit) {
UChar32 c = text.char32At(index);
// parse \s*
if (cpat == 126 /*~*/) {
if (PatternProps::isWhiteSpace(c)) {
index += U16_LENGTH(c);
continue;
} else {
if (++ipat == pat.length()) {
return index; // success; c unparsed
}
// fall thru; process c again with next cpat
}
}
// parse literal
else if (c == cpat) {
index += U16_LENGTH(c);
ipat += U16_LENGTH(cpat);
if (ipat == pat.length()) {
return index; // success; c parsed
}
// fall thru; get next cpat
}
// match failure of literal
else {
return -1;
}
cpat = pat.char32At(ipat);
}
return -1; // text ended before end of pat
}
/**
* Append a character to a rule that is being built up. To flush
* the quoteBuf to rule, make one final call with isLiteral == TRUE.
* If there is no final character, pass in (UChar32)-1 as c.
* @param rule the string to append the character to
* @param c the character to append, or (UChar32)-1 if none.
* @param isLiteral if true, then the given character should not be
* quoted or escaped. Usually this means it is a syntactic element
* such as > or $
* @param escapeUnprintable if true, then unprintable characters
* should be escaped using \uxxxx or \Uxxxxxxxx. These escapes will
* appear outside of quotes.
* @param quoteBuf a buffer which is used to build up quoted
* substrings. The caller should initially supply an empty buffer,
* and thereafter should not modify the buffer. The buffer should be
* cleared out by, at the end, calling this method with a literal
* character.
*/
void ICU_Utility::appendToRule(UnicodeString& rule,
UChar32 c,
UBool isLiteral,
UBool escapeUnprintable,
UnicodeString& quoteBuf) {
// If we are escaping unprintables, then escape them outside
// quotes. \u and \U are not recognized within quotes. The same
// logic applies to literals, but literals are never escaped.
if (isLiteral ||
(escapeUnprintable && ICU_Utility::isUnprintable(c))) {
if (quoteBuf.length() > 0) {
// We prefer backslash APOSTROPHE to double APOSTROPHE
// (more readable, less similar to ") so if there are
// double APOSTROPHEs at the ends, we pull them outside
// of the quote.
// If the first thing in the quoteBuf is APOSTROPHE
// (doubled) then pull it out.
while (quoteBuf.length() >= 2 &&
quoteBuf.charAt(0) == APOSTROPHE &&
quoteBuf.charAt(1) == APOSTROPHE) {
rule.append(BACKSLASH).append(APOSTROPHE);
quoteBuf.remove(0, 2);
}
// If the last thing in the quoteBuf is APOSTROPHE
// (doubled) then remove and count it and add it after.
int32_t trailingCount = 0;
while (quoteBuf.length() >= 2 &&
quoteBuf.charAt(quoteBuf.length()-2) == APOSTROPHE &&
quoteBuf.charAt(quoteBuf.length()-1) == APOSTROPHE) {
quoteBuf.truncate(quoteBuf.length()-2);
++trailingCount;
}
if (quoteBuf.length() > 0) {
rule.append(APOSTROPHE);
rule.append(quoteBuf);
rule.append(APOSTROPHE);
quoteBuf.truncate(0);
}
while (trailingCount-- > 0) {
rule.append(BACKSLASH).append(APOSTROPHE);
}
}
if (c != (UChar32)-1) {
/* Since spaces are ignored during parsing, they are
* emitted only for readability. We emit one here
* only if there isn't already one at the end of the
* rule.
*/
if (c == SPACE) {
int32_t len = rule.length();
if (len > 0 && rule.charAt(len-1) != c) {
rule.append(c);
}
} else if (!escapeUnprintable || !ICU_Utility::escapeUnprintable(rule, c)) {
rule.append(c);
}
}
}
// Escape ' and '\' and don't begin a quote just for them
else if (quoteBuf.length() == 0 &&
(c == APOSTROPHE || c == BACKSLASH)) {
rule.append(BACKSLASH);
rule.append(c);
}
// Specials (printable ascii that isn't [0-9a-zA-Z]) and
// whitespace need quoting. Also append stuff to quotes if we are
// building up a quoted substring already.
else if (quoteBuf.length() > 0 ||
(c >= 0x0021 && c <= 0x007E &&
!((c >= 0x0030/*'0'*/ && c <= 0x0039/*'9'*/) ||
(c >= 0x0041/*'A'*/ && c <= 0x005A/*'Z'*/) ||
(c >= 0x0061/*'a'*/ && c <= 0x007A/*'z'*/))) ||
PatternProps::isWhiteSpace(c)) {
quoteBuf.append(c);
// Double ' within a quote
if (c == APOSTROPHE) {
quoteBuf.append(c);
}
}
// Otherwise just append
else {
rule.append(c);
}
}
void ICU_Utility::appendToRule(UnicodeString& rule,
const UnicodeString& text,
UBool isLiteral,
UBool escapeUnprintable,
UnicodeString& quoteBuf) {
for (int32_t i=0; i<text.length(); ++i) {
appendToRule(rule, text[i], isLiteral, escapeUnprintable, quoteBuf);
}
}
/**
* Given a matcher reference, which may be null, append its
* pattern as a literal to the given rule.
*/
void ICU_Utility::appendToRule(UnicodeString& rule,
const UnicodeMatcher* matcher,
UBool escapeUnprintable,
UnicodeString& quoteBuf) {
if (matcher != NULL) {
UnicodeString pat;
appendToRule(rule, matcher->toPattern(pat, escapeUnprintable),
TRUE, escapeUnprintable, quoteBuf);
}
}
U_NAMESPACE_END
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