chilon Code

#ifndef CHILON_PARSER_SOURCE_CODE_STREAM_HPP
#define CHILON_PARSER_SOURCE_CODE_STREAM_HPP

#include <chilon/parser/stream.hpp>
#include <chilon/parser/choice.hpp>
#include <chilon/parser/until.hpp>
#include <chilon/parser/char.hpp>
#include <chilon/parser/any_char.hpp>
#include <chilon/parser/many.hpp>
#include <chilon/parser/without.hpp>

namespace chilon { namespace parser {

/// The default whitespace parser.
typedef choice< char_<' '>, char_<'\t'>, char_<'\n'> > whitespace;

typedef sequence<
    choice<char_<'#', ' '>, char_<'/', '/'> >,
    until<char_<'\n'>, any_char>
> default_comment;

typedef choice<whitespace, default_comment> whitespace_and_default_comment;

/// Trim whitespace from the end of a range.
template <class Whitespace>
void trim_end(range& value) {
    while (! value.empty() && Whitespace::match_char(value.back()))
        --value.end();
}

/**
 * @brief   This enhances a parser by adding several functions for skipping
 *          over and to whitespace.
 * @tparam  Parent parser type to adapt.
 * @tparam  Whitespace matcher.
 * @tparam  Comment matcher.
 */
template <class Stream = stream,
          class Whitespace = whitespace_and_default_comment>
class source_code_stream : public Stream {
    typedef many<Whitespace> skippable_t;

  public:
    /// Move assignment operator.
    template <class Rhs>
    source_code_stream& operator=(Rhs&& rhs) {
        Stream::operator=(std::move(rhs));
        return *this;
    }

    /**
     * @brief Skip whitespace and comments.
     * @details This does not check for end of file before skipping, so unless
     *          the comment or whitespace parsers do then you'd better.
     * @post    The stream points at the next non-whitespace character.
     */
    void skip_whitespace() {
        skippable_t::skip(*this);
    }

    /**
     * @brief Like skip_whitespace but remove parser in the list T
     *        from the whitespace parser when skipping.
     * @tparam T should be a meta::list containing parse objects to be
     *         removed from the whitespace parser.
     */
    template <class T>
    void skip_whitespace_without() {
        many< without<Whitespace, T> >::skip(*this);
    }

    /**
     * @brief Skip whitespace and comments.
     * @post    The stream points at the next whitespace character.
     */
    void skip_to_whitespace() {
        while (! this->empty() && ! Whitespace::match(*this)) { this->advance(); }
    }

    source_code_stream(source_code_stream const& rhs) : Stream(rhs) {}
    source_code_stream(source_code_stream&&      rhs) : Stream(std::move(rhs)) {}
    source_code_stream() {}
};

/// Source code stream with C++ style comments and whitespace.
typedef source_code_stream<
    file_stream,
    choice<
        sequence<
            char_<'/', '/'>,
            until<char_<'\n'>, any_char>
        >,
        sequence<
            char_<'/', '*'>,
            until<char_<'*', '/'>, any_char>
        >,
        whitespace
    >
> cplusplus_stream;

} }
#endif