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// © 2018 and later: Unicode, Inc. and others. 
// License & terms of use: http://www.unicode.org/copyright.html 
 
#include "unicode/utypes.h" 
 
#if !UCONFIG_NO_FORMATTING 
 
// Allow implicit conversion from char16_t* to UnicodeString for this file: 
// Helpful in toString methods and elsewhere. 
#define UNISTR_FROM_STRING_EXPLICIT 
 
#include "numparse_types.h" 
#include "numparse_scientific.h" 
#include "static_unicode_sets.h" 
#include "string_segment.h" 
 
using namespace icu; 
using namespace icu::numparse; 
using namespace icu::numparse::impl; 
 
 
namespace { 
 
inline const UnicodeSet& minusSignSet() { 
    return *unisets::get(unisets::MINUS_SIGN); 
} 
 
inline const UnicodeSet& plusSignSet() { 
    return *unisets::get(unisets::PLUS_SIGN); 
} 
 
} // namespace 
 
 
ScientificMatcher::ScientificMatcher(const DecimalFormatSymbols& dfs, const Grouper& grouper) 
        : fExponentSeparatorString(dfs.getConstSymbol(DecimalFormatSymbols::kExponentialSymbol)), 
          fExponentMatcher(dfs, grouper, PARSE_FLAG_INTEGER_ONLY | PARSE_FLAG_GROUPING_DISABLED), 
          fIgnorablesMatcher(PARSE_FLAG_STRICT_IGNORABLES) { 
 
    const UnicodeString& minusSign = dfs.getConstSymbol(DecimalFormatSymbols::kMinusSignSymbol); 
    if (minusSignSet().contains(minusSign)) { 
        fCustomMinusSign.setToBogus(); 
    } else { 
        fCustomMinusSign = minusSign; 
    } 
 
    const UnicodeString& plusSign = dfs.getConstSymbol(DecimalFormatSymbols::kPlusSignSymbol); 
    if (plusSignSet().contains(plusSign)) { 
        fCustomPlusSign.setToBogus(); 
    } else { 
        fCustomPlusSign = plusSign; 
    } 
} 
 
bool ScientificMatcher::match(StringSegment& segment, ParsedNumber& result, UErrorCode& status) const { 
    // Only accept scientific notation after the mantissa. 
    if (!result.seenNumber()) { 
        return false; 
    } 
 
    // Only accept one exponent per string. 
    if (0 != (result.flags & FLAG_HAS_EXPONENT)) { 
        return false; 
    } 
 
    // First match the scientific separator, and then match another number after it. 
    // NOTE: This is guarded by the smoke test; no need to check fExponentSeparatorString length again. 
    int32_t initialOffset = segment.getOffset(); 
    int32_t overlap = segment.getCommonPrefixLength(fExponentSeparatorString); 
    if (overlap == fExponentSeparatorString.length()) { 
        // Full exponent separator match. 
 
        // First attempt to get a code point, returning true if we can't get one. 
        if (segment.length() == overlap) { 
            return true; 
        } 
        segment.adjustOffset(overlap); 
 
        // Allow ignorables before the sign. 
        // Note: call site is guarded by the segment.length() check above. 
        // Note: the ignorables matcher should not touch the result. 
        fIgnorablesMatcher.match(segment, result, status); 
        if (segment.length() == 0) { 
            segment.setOffset(initialOffset); 
            return true; 
        } 
 
        // Allow a sign, and then try to match digits. 
        int8_t exponentSign = 1; 
        if (segment.startsWith(minusSignSet())) { 
            exponentSign = -1; 
            segment.adjustOffsetByCodePoint(); 
        } else if (segment.startsWith(plusSignSet())) { 
            segment.adjustOffsetByCodePoint(); 
        } else if (segment.startsWith(fCustomMinusSign)) { 
            overlap = segment.getCommonPrefixLength(fCustomMinusSign); 
            if (overlap != fCustomMinusSign.length()) { 
                // Partial custom sign match 
                segment.setOffset(initialOffset); 
                return true; 
            } 
            exponentSign = -1; 
            segment.adjustOffset(overlap); 
        } else if (segment.startsWith(fCustomPlusSign)) { 
            overlap = segment.getCommonPrefixLength(fCustomPlusSign); 
            if (overlap != fCustomPlusSign.length()) { 
                // Partial custom sign match 
                segment.setOffset(initialOffset); 
                return true; 
            } 
            segment.adjustOffset(overlap); 
        } 
 
        // Return true if the segment is empty. 
        if (segment.length() == 0) { 
            segment.setOffset(initialOffset); 
            return true; 
        } 
 
        // Allow ignorables after the sign. 
        // Note: call site is guarded by the segment.length() check above. 
        // Note: the ignorables matcher should not touch the result. 
        fIgnorablesMatcher.match(segment, result, status); 
        if (segment.length() == 0) { 
            segment.setOffset(initialOffset); 
            return true; 
        } 
 
        // We are supposed to accept E0 after NaN, so we need to make sure result.quantity is available. 
        bool wasBogus = result.quantity.bogus; 
        result.quantity.bogus = false; 
        int digitsOffset = segment.getOffset(); 
        bool digitsReturnValue = fExponentMatcher.match(segment, result, exponentSign, status); 
        result.quantity.bogus = wasBogus; 
 
        if (segment.getOffset() != digitsOffset) { 
            // At least one exponent digit was matched. 
            result.flags |= FLAG_HAS_EXPONENT; 
        } else { 
            // No exponent digits were matched 
            segment.setOffset(initialOffset); 
        } 
        return digitsReturnValue; 
 
    } else if (overlap == segment.length()) { 
        // Partial exponent separator match 
        return true; 
    } 
 
    // No match 
    return false; 
} 
 
bool ScientificMatcher::smokeTest(const StringSegment& segment) const { 
    return segment.startsWith(fExponentSeparatorString); 
} 
 
UnicodeString ScientificMatcher::toString() const { 
    return u"<Scientific>"; 
} 
 
 
#endif /* #if !UCONFIG_NO_FORMATTING */