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Diffstat (limited to 'intl/icu/source/common/util_props.cpp')
-rw-r--r-- | intl/icu/source/common/util_props.cpp | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/intl/icu/source/common/util_props.cpp b/intl/icu/source/common/util_props.cpp new file mode 100644 index 0000000000..5991769d06 --- /dev/null +++ b/intl/icu/source/common/util_props.cpp @@ -0,0 +1,217 @@ +// © 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) { + char16_t cpat = pattern.charAt(i); + char16_t 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 = (char16_t) 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-OUTPUT 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 + |