initial commit, 4.5 stable

thirdparty/icu4c/common/uniset_closure.cpp

@@ -0,0 +1,358 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+*******************************************************************************
+*
+*   Copyright (C) 2011, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+*******************************************************************************
+*   file name:  uniset_closure.cpp
+*   encoding:   UTF-8
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2011may30
+*   created by: Markus W. Scherer
+*
+*   UnicodeSet::closeOver() and related methods moved here from uniset_props.cpp
+*   to simplify dependencies.
+*   In particular, this depends on the BreakIterator, but the BreakIterator
+*   code also builds UnicodeSets from patterns and needs uniset_props.
+*/
+
+#include "unicode/brkiter.h"
+#include "unicode/locid.h"
+#include "unicode/parsepos.h"
+#include "unicode/uniset.h"
+#include "unicode/utf16.h"
+#include "cmemory.h"
+#include "ruleiter.h"
+#include "ucase.h"
+#include "uprops.h"
+#include "util.h"
+#include "uvector.h"
+
+U_NAMESPACE_BEGIN
+
+// TODO memory debugging provided inside uniset.cpp
+// could be made available here but probably obsolete with use of modern
+// memory leak checker tools
+#define _dbgct(me)
+
+//----------------------------------------------------------------
+// Constructors &c
+//----------------------------------------------------------------
+
+UnicodeSet::UnicodeSet(const UnicodeString& pattern,
+                       uint32_t options,
+                       const SymbolTable* symbols,
+                       UErrorCode& status) {
+    applyPattern(pattern, options, symbols, status);
+    _dbgct(this);
+}
+
+UnicodeSet::UnicodeSet(const UnicodeString& pattern, ParsePosition& pos,
+                       uint32_t options,
+                       const SymbolTable* symbols,
+                       UErrorCode& status) {
+    applyPattern(pattern, pos, options, symbols, status);
+    _dbgct(this);
+}
+
+//----------------------------------------------------------------
+// Public API
+//----------------------------------------------------------------
+
+UnicodeSet& UnicodeSet::applyPattern(const UnicodeString& pattern,
+                                     uint32_t options,
+                                     const SymbolTable* symbols,
+                                     UErrorCode& status) {
+    ParsePosition pos(0);
+    applyPattern(pattern, pos, options, symbols, status);
+    if (U_FAILURE(status)) return *this;
+
+    int32_t i = pos.getIndex();
+
+    if (options & USET_IGNORE_SPACE) {
+        // Skip over trailing whitespace
+        ICU_Utility::skipWhitespace(pattern, i, true);
+    }
+
+    if (i != pattern.length()) {
+        status = U_ILLEGAL_ARGUMENT_ERROR;
+    }
+    return *this;
+}
+
+UnicodeSet& UnicodeSet::applyPattern(const UnicodeString& pattern,
+                              ParsePosition& pos,
+                              uint32_t options,
+                              const SymbolTable* symbols,
+                              UErrorCode& status) {
+    if (U_FAILURE(status)) {
+        return *this;
+    }
+    if (isFrozen()) {
+        status = U_NO_WRITE_PERMISSION;
+        return *this;
+    }
+    // Need to build the pattern in a temporary string because
+    // _applyPattern calls add() etc., which set pat to empty.
+    UnicodeString rebuiltPat;
+    RuleCharacterIterator chars(pattern, symbols, pos);
+    applyPattern(chars, symbols, rebuiltPat, options, &UnicodeSet::closeOver, 0, status);
+    if (U_FAILURE(status)) return *this;
+    if (chars.inVariable()) {
+        // syntaxError(chars, "Extra chars in variable value");
+        status = U_MALFORMED_SET;
+        return *this;
+    }
+    setPattern(rebuiltPat);
+    return *this;
+}
+
+// USetAdder implementation
+// Does not use uset.h to reduce code dependencies
+static void U_CALLCONV
+_set_add(USet *set, UChar32 c) {
+    reinterpret_cast<UnicodeSet*>(set)->add(c);
+}
+
+static void U_CALLCONV
+_set_addRange(USet *set, UChar32 start, UChar32 end) {
+    reinterpret_cast<UnicodeSet*>(set)->add(start, end);
+}
+
+static void U_CALLCONV
+_set_addString(USet *set, const char16_t *str, int32_t length) {
+    reinterpret_cast<UnicodeSet*>(set)->add(UnicodeString(static_cast<UBool>(length < 0), str, length));
+}
+
+//----------------------------------------------------------------
+// Case folding API
+//----------------------------------------------------------------
+
+// add the result of a full case mapping to the set
+// use str as a temporary string to avoid constructing one
+static inline void
+addCaseMapping(UnicodeSet &set, int32_t result, const char16_t *full, UnicodeString &str) {
+    if(result >= 0) {
+        if(result > UCASE_MAX_STRING_LENGTH) {
+            // add a single-code point case mapping
+            set.add(result);
+        } else {
+            // add a string case mapping from full with length result
+            str.setTo(static_cast<UBool>(false), full, result);
+            set.add(str);
+        }
+    }
+    // result < 0: the code point mapped to itself, no need to add it
+    // see ucase.h
+}
+
+namespace {
+
+/** For case closure on a large set, look only at code points with relevant properties. */
+const UnicodeSet &maybeOnlyCaseSensitive(const UnicodeSet &src, UnicodeSet &subset) {
+    // The subset must have been constructed with all code points,
+    // so that the retainAll() intersection effectively copies all single code points from src.
+    U_ASSERT(subset.contains(0, 0x10ffff));
+    if (src.size() < 30) {
+        return src;
+    }
+    // Return the intersection of the src code points with Case_Sensitive ones.
+    UErrorCode errorCode = U_ZERO_ERROR;
+    const UnicodeSet *sensitive =
+        CharacterProperties::getBinaryPropertySet(UCHAR_CASE_SENSITIVE, errorCode);
+    if (U_FAILURE(errorCode)) {
+        return src;
+    }
+    // Start by copying the "smaller" set.
+    // (We "copy" by intersecting all Unicode *code points* with the first set,
+    // which omits any strings.)
+    if (src.getRangeCount() > sensitive->getRangeCount()) {
+        subset.retainAll(*sensitive);
+        subset.retainAll(src);
+    } else {
+        subset.retainAll(src);
+        subset.retainAll(*sensitive);
+    }
+    return subset;
+}
+
+// Per-character scf = Simple_Case_Folding of a string.
+// (Normally when we case-fold a string we use full case foldings.)
+bool scfString(const UnicodeString &s, UnicodeString &scf) {
+    // Iterate over the raw buffer for best performance.
+    const char16_t *p = s.getBuffer();
+    int32_t length = s.length();
+    // Loop while not needing modification.
+    for (int32_t i = 0; i < length;) {
+        UChar32 c;
+        U16_NEXT(p, i, length, c);  // post-increments i
+        UChar32 scfChar = u_foldCase(c, U_FOLD_CASE_DEFAULT);
+        if (scfChar != c) {
+            // Copy the characters before c.
+            scf.setTo(p, i - U16_LENGTH(c));
+            // Loop over the rest of the string and keep case-folding.
+            for (;;) {
+                scf.append(scfChar);
+                if (i == length) {
+                    return true;
+                }
+                U16_NEXT(p, i, length, c);  // post-increments i
+                scfChar = u_foldCase(c, U_FOLD_CASE_DEFAULT);
+            }
+        }
+    }
+    return false;
+}
+
+}  // namespace
+
+UnicodeSet& UnicodeSet::closeOver(int32_t attribute) {
+    if (isFrozen() || isBogus()) {
+        return *this;
+    }
+    switch (attribute & USET_CASE_MASK) {
+    case 0:
+        break;
+    case USET_CASE_INSENSITIVE:
+        closeOverCaseInsensitive(/* simple= */ false);
+        break;
+    case USET_ADD_CASE_MAPPINGS:
+        closeOverAddCaseMappings();
+        break;
+    case USET_SIMPLE_CASE_INSENSITIVE:
+        closeOverCaseInsensitive(/* simple= */ true);
+        break;
+    default:
+        // bad option (unreachable)
+        break;
+    }
+    return *this;
+}
+
+void UnicodeSet::closeOverCaseInsensitive(bool simple) {
+    // Start with input set to guarantee inclusion.
+    UnicodeSet foldSet(*this);
+    // Full case mappings closure:
+    // Remove strings because the strings will actually be reduced (folded);
+    // therefore, start with no strings and add only those needed.
+    // Do this before processing code points, because they may add strings.
+    if (!simple && foldSet.hasStrings()) {
+        foldSet.strings_->removeAllElements();
+    }
+
+    USetAdder sa = {
+        foldSet.toUSet(),
+        _set_add,
+        _set_addRange,
+        _set_addString,
+        nullptr, // don't need remove()
+        nullptr // don't need removeRange()
+    };
+
+    UnicodeSet subset(0, 0x10ffff);
+    const UnicodeSet &codePoints = maybeOnlyCaseSensitive(*this, subset);
+
+    // Iterate over the ranges of single code points. Nested loop for each code point.
+    int32_t n = codePoints.getRangeCount();
+
+    for (int32_t i=0; i<n; ++i) {
+        UChar32 start = codePoints.getRangeStart(i);
+        UChar32 end   = codePoints.getRangeEnd(i);
+
+        if (simple) {
+            for (UChar32 cp=start; cp<=end; ++cp) {
+                ucase_addSimpleCaseClosure(cp, &sa);
+            }
+        } else {
+            for (UChar32 cp=start; cp<=end; ++cp) {
+                ucase_addCaseClosure(cp, &sa);
+            }
+        }
+    }
+    if (hasStrings()) {
+        UnicodeString str;
+        for (int32_t j=0; j<strings_->size(); ++j) {
+            const UnicodeString* pStr = static_cast<const UnicodeString*>(strings_->elementAt(j));
+            if (simple) {
+                if (scfString(*pStr, str)) {
+                    foldSet.remove(*pStr).add(str);
+                }
+            } else {
+                str = *pStr;
+                str.foldCase();
+                if(!ucase_addStringCaseClosure(str.getBuffer(), str.length(), &sa)) {
+                    foldSet.add(str); // does not map to code points: add the folded string itself
+                }
+            }
+        }
+    }
+    *this = foldSet;
+}
+
+void UnicodeSet::closeOverAddCaseMappings() {
+    // Start with input set to guarantee inclusion.
+    UnicodeSet foldSet(*this);
+
+    UnicodeSet subset(0, 0x10ffff);
+    const UnicodeSet &codePoints = maybeOnlyCaseSensitive(*this, subset);
+
+    // Iterate over the ranges of single code points. Nested loop for each code point.
+    int32_t n = codePoints.getRangeCount();
+    UChar32 result;
+    const char16_t *full;
+    UnicodeString str;
+
+    for (int32_t i=0; i<n; ++i) {
+        UChar32 start = codePoints.getRangeStart(i);
+        UChar32 end   = codePoints.getRangeEnd(i);
+
+        // add case mappings
+        // (does not add long s for regular s, or Kelvin for k, for example)
+        for (UChar32 cp=start; cp<=end; ++cp) {
+            result = ucase_toFullLower(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);
+            addCaseMapping(foldSet, result, full, str);
+
+            result = ucase_toFullTitle(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);
+            addCaseMapping(foldSet, result, full, str);
+
+            result = ucase_toFullUpper(cp, nullptr, nullptr, &full, UCASE_LOC_ROOT);
+            addCaseMapping(foldSet, result, full, str);
+
+            result = ucase_toFullFolding(cp, &full, 0);
+            addCaseMapping(foldSet, result, full, str);
+        }
+    }
+    if (hasStrings()) {
+        Locale root("");
+#if !UCONFIG_NO_BREAK_ITERATION
+        UErrorCode status = U_ZERO_ERROR;
+        BreakIterator *bi = BreakIterator::createWordInstance(root, status);
+        if (U_SUCCESS(status)) {
+#endif
+            for (int32_t j=0; j<strings_->size(); ++j) {
+                const UnicodeString* pStr = static_cast<const UnicodeString*>(strings_->elementAt(j));
+                (str = *pStr).toLower(root);
+                foldSet.add(str);
+#if !UCONFIG_NO_BREAK_ITERATION
+                (str = *pStr).toTitle(bi, root);
+                foldSet.add(str);
+#endif
+                (str = *pStr).toUpper(root);
+                foldSet.add(str);
+                (str = *pStr).foldCase();
+                foldSet.add(str);
+            }
+#if !UCONFIG_NO_BREAK_ITERATION
+        }
+        delete bi;
+#endif
+    }
+    *this = foldSet;
+}
+
+U_NAMESPACE_END