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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
**********************************************************************
* Copyright (c) 2001-2016, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/19/2001 aliu Creation.
**********************************************************************
*/
#include "unicode/uchar.h"
#include "unicode/utf16.h"
#include "patternprops.h"
#include "util.h"
U_NAMESPACE_BEGIN
/**
* Parse an integer at pos, either of the form \d+ or of the form
* 0x[0-9A-Fa-f]+ or 0[0-7]+, that is, in standard decimal, hex,
* or octal format.
* @param pos INPUT-OUTPUT parameter. On input, the first
* character to parse. On output, the character after the last
* parsed character.
*/
int32_t ICU_Utility::parseInteger(const UnicodeString& rule, int32_t& pos, int32_t limit) {
int32_t count = 0;
int32_t value = 0;
int32_t p = pos;
int8_t radix = 10;
if (p < limit && rule.charAt(p) == 48 /*0*/) {
if (p+1 < limit && (rule.charAt(p+1) == 0x78 /*x*/ || rule.charAt(p+1) == 0x58 /*X*/)) {
p += 2;
radix = 16;
}
else {
p++;
count = 1;
radix = 8;
}
}
while (p < limit) {
int32_t d = u_digit(rule.charAt(p++), radix);
if (d < 0) {
--p;
break;
}
++count;
int32_t v = (value * radix) + d;
if (v <= value) {
// If there are too many input digits, at some point
// the value will go negative, e.g., if we have seen
// "0x8000000" already and there is another '0', when
// we parse the next 0 the value will go negative.
return 0;
}
value = v;
}
if (count > 0) {
pos = p;
}
return value;
}
/**
* Parse a pattern string starting at offset pos. Keywords are
* matched case-insensitively. Spaces may be skipped and may be
* optional or required. Integer values may be parsed, and if
* they are, they will be returned in the given array. If
* successful, the offset of the next non-space character is
* returned. On failure, -1 is returned.
* @param pattern must only contain lowercase characters, which
* will match their uppercase equivalents as well. A space
* character matches one or more required spaces. A '~' character
* matches zero or more optional spaces. A '#' character matches
* an integer and stores it in parsedInts, which the caller must
* ensure has enough capacity.
* @param parsedInts array to receive parsed integers. Caller
* must ensure that parsedInts.length is >= the number of '#'
* signs in 'pattern'.
* @return the position after the last character parsed, or -1 if
* the parse failed
*/
int32_t ICU_Utility::parsePattern(const UnicodeString& rule, int32_t pos, int32_t limit,
const UnicodeString& pattern, int32_t* parsedInts) {
// TODO Update this to handle surrogates
int32_t p;
int32_t intCount = 0; // number of integers parsed
for (int32_t i=0; i<pattern.length(); ++i) {
UChar cpat = pattern.charAt(i);
UChar c;
switch (cpat) {
case 32 /*' '*/:
if (pos >= limit) {
return -1;
}
c = rule.charAt(pos++);
if (!PatternProps::isWhiteSpace(c)) {
return -1;
}
// FALL THROUGH to skipWhitespace
U_FALLTHROUGH;
case 126 /*'~'*/:
pos = skipWhitespace(rule, pos);
break;
case 35 /*'#'*/:
p = pos;
parsedInts[intCount++] = parseInteger(rule, p, limit);
if (p == pos) {
// Syntax error; failed to parse integer
return -1;
}
pos = p;
break;
default:
if (pos >= limit) {
return -1;
}
c = (UChar) u_tolower(rule.charAt(pos++));
if (c != cpat) {
return -1;
}
break;
}
}
return pos;
}
/**
* Parse a Unicode identifier from the given string at the given
* position. Return the identifier, or an empty string if there
* is no identifier.
* @param str the string to parse
* @param pos INPUT-OUPUT parameter. On INPUT, pos is the
* first character to examine. It must be less than str.length(),
* and it must not point to a whitespace character. That is, must
* have pos < str.length(). On
* OUTPUT, the position after the last parsed character.
* @return the Unicode identifier, or an empty string if there is
* no valid identifier at pos.
*/
UnicodeString ICU_Utility::parseUnicodeIdentifier(const UnicodeString& str, int32_t& pos) {
// assert(pos < str.length());
UnicodeString buf;
int p = pos;
while (p < str.length()) {
UChar32 ch = str.char32At(p);
if (buf.length() == 0) {
if (u_isIDStart(ch)) {
buf.append(ch);
} else {
buf.truncate(0);
return buf;
}
} else {
if (u_isIDPart(ch)) {
buf.append(ch);
} else {
break;
}
}
p += U16_LENGTH(ch);
}
pos = p;
return buf;
}
/**
* Parse an unsigned 31-bit integer at the given offset. Use
* UCharacter.digit() to parse individual characters into digits.
* @param text the text to be parsed
* @param pos INPUT-OUTPUT parameter. On entry, pos[0] is the
* offset within text at which to start parsing; it should point
* to a valid digit. On exit, pos[0] is the offset after the last
* parsed character. If the parse failed, it will be unchanged on
* exit. Must be >= 0 on entry.
* @param radix the radix in which to parse; must be >= 2 and <=
* 36.
* @return a non-negative parsed number, or -1 upon parse failure.
* Parse fails if there are no digits, that is, if pos[0] does not
* point to a valid digit on entry, or if the number to be parsed
* does not fit into a 31-bit unsigned integer.
*/
int32_t ICU_Utility::parseNumber(const UnicodeString& text,
int32_t& pos, int8_t radix) {
// assert(pos[0] >= 0);
// assert(radix >= 2);
// assert(radix <= 36);
int32_t n = 0;
int32_t p = pos;
while (p < text.length()) {
UChar32 ch = text.char32At(p);
int32_t d = u_digit(ch, radix);
if (d < 0) {
break;
}
n = radix*n + d;
// ASSUME that when a 32-bit integer overflows it becomes
// negative. E.g., 214748364 * 10 + 8 => negative value.
if (n < 0) {
return -1;
}
++p;
}
if (p == pos) {
return -1;
}
pos = p;
return n;
}
U_NAMESPACE_END
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