-/**
- * 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 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() and
- * !uprv_isRuleWhiteSpace(str.char32At(pos)). 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());
- // assert(!uprv_isRuleWhiteSpace(str.char32At(pos)));
- 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 += UTF_CHAR_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;
-}
-
projects / apple / icu.git / blobdiff