reader.cpp

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#ifndef Om_Language_Reader_
 
    #include "om/language/reader.hpp"
 
#else
 
    #include "om/language/symbol/operand_symbol.hpp"
    #include "om/language/symbol/operator_symbol.hpp"
    #include "om/language/symbol/separator_symbol.hpp"
 
// MARK: - Om::Language::Reader
 
    #define Type_ \
    Om::Language::Reader
 
// MARK: public (non-static)
 
inline Type_::Reader(
    Om::Source::Source<CodePoint const> & theCodePointSource
):
thisCodePointSource(theCodePointSource),
thisDepth(),
thisIsEncoded() {}
 
inline Om::CodePoint const & Type_::operator *() const {
    assert(
        !this->operator !()
    );
    return *this->thisCodePointSource;
}
 
inline bool Type_::operator !() const {
    return (
        !this->thisCodePointSource ||
        (
            !this->thisDepth &&
            !this->thisIsEncoded &&
            Symbol::theEndOperandSymbol == *this->thisCodePointSource
        )
    );
}
 
inline bool Type_::Equals(Reader const & theReader) const {
    assert(
        this->thisCodePointSource != theReader.thisCodePointSource ||
        this->thisDepth == theReader.thisDepth
    );
    return this->thisCodePointSource == theReader.thisCodePointSource;
}
 
inline void Type_::Pop() {
    assert(this->thisCodePointSource);
    switch (*this->thisCodePointSource) {
    case Symbol::theStartOperandSymbol:
        if (this->thisIsEncoded) {
            this->thisIsEncoded = false;
        } else {
            if (
                static_cast<size_t>(-1) == this->thisDepth
            ) {
                throw std::overflow_error("Operand overflow.");
            }
            ++this->thisDepth;
        }
        break;
    case Symbol::theEndOperandSymbol:
        if (this->thisIsEncoded) {
            this->thisIsEncoded = false;
        } else {
            assert(this->thisDepth);
            --this->thisDepth;
        }
        break;
    case Symbol::theEncodeOperatorSymbol:
        this->thisIsEncoded = !this->thisIsEncoded;
        break;
    default:
        this->thisIsEncoded = false;
        // Fall through.
    }
    this->thisCodePointSource.Pop();
}
 
// MARK: - Om::Language::
 
inline bool Om::Language::operator ==(
    Type_ const & theFirst,
    Type_ const & theSecond
) {
    return theFirst.Equals(theSecond);
}
 
inline bool Om::Language::operator !=(
    Type_ const & theFirst,
    Type_ const & theSecond
) {
    return !theFirst.Equals(theSecond);
}
 
    #undef Type_
 
#endif