Common Text Transformation Library: functor.cpp

// sample code: functor.cpp
// demonstrates function object rule_char used inside grammar rule.

#include "cttl/cttl.h"

using namespace cttl;

class rule_char : public std::unary_function< const_edge<>, size_t >{
    char m_char;

public:
    rule_char( char char_ )
        :   m_char( char_ )
    {}

    size_t operator() ( const_edge<>& edge_ ) const
    {
        return symbol( m_char ).match( edge_ );
    }
};


int main()
{
    input<> inp( "ZZZA" );
    const_edge<> U( new_edge( inp ) );
    char L = 'Z';
    rule_char R( L );           // construct grammar rule for a single character
    // the following statement describes grammar production rule R+ 'A'
    // and evaluates this grammar against specified universe by
    // invoking "match()" evaluation method:
    size_t P = ( +rule( R ) + 'A' ).match( U );
    assert( P == 0 );           // assert match found at the beginning of U
    assert( U.length() == 0 );  // make sure universe is fully consumed
    return 0;
}

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