--- /dev/null
+/*
+**********************************************************************
+* 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
+
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