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Diffstat (limited to 'intl/icu/source/common/util.cpp')
| -rw-r--r-- | intl/icu/source/common/util.cpp | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/intl/icu/source/common/util.cpp b/intl/icu/source/common/util.cpp new file mode 100644 index 000000000..1b77110c6 --- /dev/null +++ b/intl/icu/source/common/util.cpp @@ -0,0 +1,411 @@ +// Copyright (C) 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +********************************************************************** +* Copyright (c) 2001-2011, International Business Machines +* Corporation and others. All Rights Reserved. +********************************************************************** +* Date Name Description +* 11/19/2001 aliu Creation. +********************************************************************** +*/ + +#include "unicode/unimatch.h" +#include "unicode/utf16.h" +#include "patternprops.h" +#include "util.h" + +// Define UChar constants using hex for EBCDIC compatibility + +static const UChar BACKSLASH = 0x005C; /*\*/ +static const UChar UPPER_U = 0x0055; /*U*/ +static const UChar LOWER_U = 0x0075; /*u*/ +static const UChar APOSTROPHE = 0x0027; // '\'' +static const UChar SPACE = 0x0020; // ' ' + +// "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" +static const UChar DIGITS[] = { + 48,49,50,51,52,53,54,55,56,57, + 65,66,67,68,69,70,71,72,73,74, + 75,76,77,78,79,80,81,82,83,84, + 85,86,87,88,89,90 +}; + +U_NAMESPACE_BEGIN + +UnicodeString& ICU_Utility::appendNumber(UnicodeString& result, int32_t n, + int32_t radix, int32_t minDigits) { + if (radix < 2 || radix > 36) { + // Bogus radix + return result.append((UChar)63/*?*/); + } + // Handle negatives + if (n < 0) { + n = -n; + result.append((UChar)45/*-*/); + } + // First determine the number of digits + int32_t nn = n; + int32_t r = 1; + while (nn >= radix) { + nn /= radix; + r *= radix; + --minDigits; + } + // Now generate the digits + while (--minDigits > 0) { + result.append(DIGITS[0]); + } + while (r > 0) { + int32_t digit = n / r; + result.append(DIGITS[digit]); + n -= digit * r; + r /= radix; + } + return result; +} + +/** + * Return true if the character is NOT printable ASCII. + */ +UBool ICU_Utility::isUnprintable(UChar32 c) { + return !(c >= 0x20 && c <= 0x7E); +} + +/** + * Escape unprintable characters using \uxxxx notation for U+0000 to + * U+FFFF and \Uxxxxxxxx for U+10000 and above. If the character is + * printable ASCII, then do nothing and return FALSE. Otherwise, + * append the escaped notation and return TRUE. + */ +UBool ICU_Utility::escapeUnprintable(UnicodeString& result, UChar32 c) { + if (isUnprintable(c)) { + result.append(BACKSLASH); + if (c & ~0xFFFF) { + result.append(UPPER_U); + result.append(DIGITS[0xF&(c>>28)]); + result.append(DIGITS[0xF&(c>>24)]); + result.append(DIGITS[0xF&(c>>20)]); + result.append(DIGITS[0xF&(c>>16)]); + } else { + result.append(LOWER_U); + } + result.append(DIGITS[0xF&(c>>12)]); + result.append(DIGITS[0xF&(c>>8)]); + result.append(DIGITS[0xF&(c>>4)]); + result.append(DIGITS[0xF&c]); + return TRUE; + } + return FALSE; +} + +/** + * Returns the index of a character, ignoring quoted text. + * For example, in the string "abc'hide'h", the 'h' in "hide" will not be + * found by a search for 'h'. + */ +// FOR FUTURE USE. DISABLE FOR NOW for coverage reasons. +/* +int32_t ICU_Utility::quotedIndexOf(const UnicodeString& text, + int32_t start, int32_t limit, + UChar charToFind) { + for (int32_t i=start; i<limit; ++i) { + UChar c = text.charAt(i); + if (c == BACKSLASH) { + ++i; + } else if (c == APOSTROPHE) { + while (++i < limit + && text.charAt(i) != APOSTROPHE) {} + } else if (c == charToFind) { + return i; + } + } + return -1; +} +*/ + +/** + * Skip over a sequence of zero or more white space characters at pos. + * @param advance if true, advance pos to the first non-white-space + * character at or after pos, or str.length(), if there is none. + * Otherwise leave pos unchanged. + * @return the index of the first non-white-space character at or + * after pos, or str.length(), if there is none. + */ +int32_t ICU_Utility::skipWhitespace(const UnicodeString& str, int32_t& pos, + UBool advance) { + int32_t p = pos; + const UChar* s = str.getBuffer(); + p = (int32_t)(PatternProps::skipWhiteSpace(s + p, str.length() - p) - s); + if (advance) { + pos = p; + } + return p; +} + +/** + * Skip over Pattern_White_Space in a Replaceable. + * Skipping may be done in the forward or + * reverse direction. In either case, the leftmost index will be + * inclusive, and the rightmost index will be exclusive. That is, + * given a range defined as [start, limit), the call + * skipWhitespace(text, start, limit) will advance start past leading + * whitespace, whereas the call skipWhitespace(text, limit, start), + * will back up limit past trailing whitespace. + * @param text the text to be analyzed + * @param pos either the start or limit of a range of 'text', to skip + * leading or trailing whitespace, respectively + * @param stop either the limit or start of a range of 'text', to skip + * leading or trailing whitespace, respectively + * @return the new start or limit, depending on what was passed in to + * 'pos' + */ +//?FOR FUTURE USE. DISABLE FOR NOW for coverage reasons. +//?int32_t ICU_Utility::skipWhitespace(const Replaceable& text, +//? int32_t pos, int32_t stop) { +//? UChar32 c; +//? UBool isForward = (stop >= pos); +//? +//? if (!isForward) { +//? --pos; // pos is a limit, so back up by one +//? } +//? +//? while (pos != stop && +//? PatternProps::isWhiteSpace(c = text.char32At(pos))) { +//? if (isForward) { +//? pos += U16_LENGTH(c); +//? } else { +//? pos -= U16_LENGTH(c); +//? } +//? } +//? +//? if (!isForward) { +//? ++pos; // make pos back into a limit +//? } +//? +//? return pos; +//?} + +/** + * Parse a single non-whitespace character 'ch', optionally + * preceded by whitespace. + * @param id the string to be parsed + * @param pos INPUT-OUTPUT parameter. On input, pos[0] is the + * offset of the first character to be parsed. On output, pos[0] + * is the index after the last parsed character. If the parse + * fails, pos[0] will be unchanged. + * @param ch the non-whitespace character to be parsed. + * @return true if 'ch' is seen preceded by zero or more + * whitespace characters. + */ +UBool ICU_Utility::parseChar(const UnicodeString& id, int32_t& pos, UChar ch) { + int32_t start = pos; + skipWhitespace(id, pos, TRUE); + if (pos == id.length() || + id.charAt(pos) != ch) { + pos = start; + return FALSE; + } + ++pos; + return TRUE; +} + +/** + * Parse a pattern string within the given Replaceable and a parsing + * pattern. Characters are matched literally and case-sensitively + * except for the following special characters: + * + * ~ zero or more Pattern_White_Space chars + * + * If end of pattern is reached with all matches along the way, + * pos is advanced to the first unparsed index and returned. + * Otherwise -1 is returned. + * @param pat pattern that controls parsing + * @param text text to be parsed, starting at index + * @param index offset to first character to parse + * @param limit offset after last character to parse + * @return index after last parsed character, or -1 on parse failure. + */ +int32_t ICU_Utility::parsePattern(const UnicodeString& pat, + const Replaceable& text, + int32_t index, + int32_t limit) { + int32_t ipat = 0; + + // empty pattern matches immediately + if (ipat == pat.length()) { + return index; + } + + UChar32 cpat = pat.char32At(ipat); + + while (index < limit) { + UChar32 c = text.char32At(index); + + // parse \s* + if (cpat == 126 /*~*/) { + if (PatternProps::isWhiteSpace(c)) { + index += U16_LENGTH(c); + continue; + } else { + if (++ipat == pat.length()) { + return index; // success; c unparsed + } + // fall thru; process c again with next cpat + } + } + + // parse literal + else if (c == cpat) { + index += U16_LENGTH(c); + ipat += U16_LENGTH(cpat); + if (ipat == pat.length()) { + return index; // success; c parsed + } + // fall thru; get next cpat + } + + // match failure of literal + else { + return -1; + } + + cpat = pat.char32At(ipat); + } + + return -1; // text ended before end of pat +} + +/** + * Append a character to a rule that is being built up. To flush + * the quoteBuf to rule, make one final call with isLiteral == TRUE. + * If there is no final character, pass in (UChar32)-1 as c. + * @param rule the string to append the character to + * @param c the character to append, or (UChar32)-1 if none. + * @param isLiteral if true, then the given character should not be + * quoted or escaped. Usually this means it is a syntactic element + * such as > or $ + * @param escapeUnprintable if true, then unprintable characters + * should be escaped using \uxxxx or \Uxxxxxxxx. These escapes will + * appear outside of quotes. + * @param quoteBuf a buffer which is used to build up quoted + * substrings. The caller should initially supply an empty buffer, + * and thereafter should not modify the buffer. The buffer should be + * cleared out by, at the end, calling this method with a literal + * character. + */ +void ICU_Utility::appendToRule(UnicodeString& rule, + UChar32 c, + UBool isLiteral, + UBool escapeUnprintable, + UnicodeString& quoteBuf) { + // If we are escaping unprintables, then escape them outside + // quotes. \u and \U are not recognized within quotes. The same + // logic applies to literals, but literals are never escaped. + if (isLiteral || + (escapeUnprintable && ICU_Utility::isUnprintable(c))) { + if (quoteBuf.length() > 0) { + // We prefer backslash APOSTROPHE to double APOSTROPHE + // (more readable, less similar to ") so if there are + // double APOSTROPHEs at the ends, we pull them outside + // of the quote. + + // If the first thing in the quoteBuf is APOSTROPHE + // (doubled) then pull it out. + while (quoteBuf.length() >= 2 && + quoteBuf.charAt(0) == APOSTROPHE && + quoteBuf.charAt(1) == APOSTROPHE) { + rule.append(BACKSLASH).append(APOSTROPHE); + quoteBuf.remove(0, 2); + } + // If the last thing in the quoteBuf is APOSTROPHE + // (doubled) then remove and count it and add it after. + int32_t trailingCount = 0; + while (quoteBuf.length() >= 2 && + quoteBuf.charAt(quoteBuf.length()-2) == APOSTROPHE && + quoteBuf.charAt(quoteBuf.length()-1) == APOSTROPHE) { + quoteBuf.truncate(quoteBuf.length()-2); + ++trailingCount; + } + if (quoteBuf.length() > 0) { + rule.append(APOSTROPHE); + rule.append(quoteBuf); + rule.append(APOSTROPHE); + quoteBuf.truncate(0); + } + while (trailingCount-- > 0) { + rule.append(BACKSLASH).append(APOSTROPHE); + } + } + if (c != (UChar32)-1) { + /* Since spaces are ignored during parsing, they are + * emitted only for readability. We emit one here + * only if there isn't already one at the end of the + * rule. + */ + if (c == SPACE) { + int32_t len = rule.length(); + if (len > 0 && rule.charAt(len-1) != c) { + rule.append(c); + } + } else if (!escapeUnprintable || !ICU_Utility::escapeUnprintable(rule, c)) { + rule.append(c); + } + } + } + + // Escape ' and '\' and don't begin a quote just for them + else if (quoteBuf.length() == 0 && + (c == APOSTROPHE || c == BACKSLASH)) { + rule.append(BACKSLASH); + rule.append(c); + } + + // Specials (printable ascii that isn't [0-9a-zA-Z]) and + // whitespace need quoting. Also append stuff to quotes if we are + // building up a quoted substring already. + else if (quoteBuf.length() > 0 || + (c >= 0x0021 && c <= 0x007E && + !((c >= 0x0030/*'0'*/ && c <= 0x0039/*'9'*/) || + (c >= 0x0041/*'A'*/ && c <= 0x005A/*'Z'*/) || + (c >= 0x0061/*'a'*/ && c <= 0x007A/*'z'*/))) || + PatternProps::isWhiteSpace(c)) { + quoteBuf.append(c); + // Double ' within a quote + if (c == APOSTROPHE) { + quoteBuf.append(c); + } + } + + // Otherwise just append + else { + rule.append(c); + } +} + +void ICU_Utility::appendToRule(UnicodeString& rule, + const UnicodeString& text, + UBool isLiteral, + UBool escapeUnprintable, + UnicodeString& quoteBuf) { + for (int32_t i=0; i<text.length(); ++i) { + appendToRule(rule, text[i], isLiteral, escapeUnprintable, quoteBuf); + } +} + +/** + * Given a matcher reference, which may be null, append its + * pattern as a literal to the given rule. + */ +void ICU_Utility::appendToRule(UnicodeString& rule, + const UnicodeMatcher* matcher, + UBool escapeUnprintable, + UnicodeString& quoteBuf) { + if (matcher != NULL) { + UnicodeString pat; + appendToRule(rule, matcher->toPattern(pat, escapeUnprintable), + TRUE, escapeUnprintable, quoteBuf); + } +} + +U_NAMESPACE_END |