lean2/src/frontends/lean/scanner.h

81 lines
2.7 KiB
C++

/*
Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <string>
#include <iostream>
#include "util/name.h"
#include "util/numerics/mpq.h"
#include "kernel/environment.h"
#include "frontends/lean/token_table.h"
namespace lean {
/**
\brief Scanner. The behavior of the scanner is controlled using a token set.
The scanner has builtin support for comments, script blocks,
identifiers, numerals, decimals, strings. Everything else is only
accepted if they are in the token set.
*/
class scanner {
public:
enum class token_kind {Keyword, CommandKeyword, ScriptBlock, Identifier, Numeral, Decimal, String, QuotedSymbol, Eof};
protected:
token_table const * m_tokens;
std::istream & m_stream;
std::string m_stream_name;
int m_spos; // current position
int m_sline; // current line
char m_curr; // current char;
int m_pos; // start position of the token
int m_line; // line of the token
name m_name_val;
token_info const * m_token_info;
mpq m_num_val;
std::string m_buffer;
std::string m_aux_buffer;
[[ noreturn ]] void throw_exception(char const * msg);
void next();
char curr() const { return m_curr; }
char curr_next() { char c = curr(); next(); return c; }
void new_line() { m_sline++; m_spos = 0; }
void update_line() { if (curr() == '\n') new_line(); }
void check_not_eof(char const * error_msg);
bool is_next_digit();
bool is_next_id_rest();
void move_back(std::streamoff offset);
bool consume(char const * str, char const * error_msg);
void read_single_line_comment();
void read_comment_block();
void read_until(char const * end_str, char const * error_msg);
token_kind read_string();
token_kind read_number();
token_kind read_script_block();
token_kind read_key_cmd_id();
token_kind read_quoted_symbol();
public:
scanner(std::istream & strm, char const * strm_name = nullptr);
int get_line() const { return m_line; }
int get_pos() const { return m_pos; }
token_kind scan(environment const & env);
void set_line(unsigned p);
mpq const & get_num_val() const { return m_num_val; }
name const & get_name_val() const { return m_name_val; }
std::string const & get_str_val() const { return m_buffer; }
token_info const & get_token_info() const { lean_assert(m_token_info); return *m_token_info; }
std::string const & get_stream_name() const { return m_stream_name; }
};
std::ostream & operator<<(std::ostream & out, scanner::token_kind k);
}