TlpLexer.h

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#pragma once
 
#include <cstddef>
#include <iostream>
#include <iterator>
#include <string>
#include <vector>
 
namespace ogdf {
 
namespace tlp {
 
 
struct Token {
    enum class Type { leftParen, rightParen, identifier, string } type;
 
    std::string* value; // Optional token value (avaliable in id and string).
    size_t line, column; // Where given token occured for printing nice info.
 
    Token(const Type& type, size_t line, size_t column);
    friend std::ostream& operator<<(std::istream& os, const Token& token);
 
    bool inline leftParen() const { return type == Type::leftParen; }
 
    bool inline rightParen() const { return type == Type::rightParen; }
 
    bool inline identifier() const { return type == Type::identifier; }
 
    bool inline identifier(const char* str) const {
        return type == Type::identifier && *value == str;
    }
 
    bool inline string() const { return type == Type::string; }
 
    bool inline string(const char* str) const { return type == Type::string && *value == str; }
};
 
std::ostream& operator<<(std::ostream& os, const Token& token);
 
class Lexer {
private:
    std::istream& m_istream;
    std::string m_buffer;
    std::string::const_iterator m_begin, m_end;
    size_t m_line;
 
    std::vector<Token> m_tokens;
 
    bool fetchBuffer();
    void cleanValues();
 
    bool tokenizeLine();
    bool tokenizeString();
    bool tokenizeIdentifier();
 
    size_t line() const { return m_line; }
 
    size_t column() const { return std::distance(m_buffer.begin(), m_begin) + 1; }
 
    static bool isIdentifier(char c);
 
public:
    explicit Lexer(std::istream& is);
    ~Lexer();
 
    bool tokenize();
 
    const std::vector<Token>& tokens() const { return m_tokens; }
};
 
}
}