| // © 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 |
| |
