/* ********************************************************************** * Copyright (c) 2001-2006, International Business Machines * Corporation and others. All Rights Reserved. ********************************************************************** * Date Name Description * 11/19/2001 aliu Creation. ********************************************************************** */ #include "util.h" #include "unicode/uchar.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 (!uprv_isRuleWhiteSpace(c)) { return -1; } // FALL THROUGH to skipWhitespace 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() 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; } U_NAMESPACE_END