332 lines
9.1 KiB
C++
332 lines
9.1 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 <cctype>
|
|
#include <string>
|
|
#include "util/exception.h"
|
|
#include "frontends/lean/scanner.h"
|
|
|
|
namespace lean {
|
|
void scanner::next() {
|
|
lean_assert(m_curr != EOF);
|
|
m_curr = m_stream.get();
|
|
m_spos++;
|
|
}
|
|
|
|
void scanner::check_not_eof(char const * error_msg) const {
|
|
if (curr() == EOF) throw_exception(error_msg);
|
|
}
|
|
|
|
[[ noreturn ]] void scanner::throw_exception(char const * msg) const {
|
|
throw parser_exception(msg, m_stream_name.c_str(), m_sline, m_spos);
|
|
}
|
|
|
|
auto scanner::read_string() -> token_kind {
|
|
static char const * end_error_msg = "unexpected end of string";
|
|
lean_assert(curr() == '\"');
|
|
next();
|
|
m_buffer.clear();
|
|
while (true) {
|
|
check_not_eof(end_error_msg);
|
|
update_line();
|
|
char c = curr();
|
|
if (c == '\"') {
|
|
next();
|
|
return token_kind::String;
|
|
} else if (c == '\\') {
|
|
next();
|
|
check_not_eof(end_error_msg);
|
|
c = curr();
|
|
if (c != '\\' && c != '\"' && c != 'n')
|
|
throw_exception("invalid escape sequence");
|
|
if (c == 'n')
|
|
c = '\n';
|
|
}
|
|
m_buffer += c;
|
|
next();
|
|
}
|
|
}
|
|
|
|
bool scanner::is_next_digit() {
|
|
lean_assert(curr() != EOF);
|
|
char c = m_stream.get();
|
|
bool r = std::isdigit(c);
|
|
m_stream.unget();
|
|
return r;
|
|
}
|
|
|
|
auto scanner::read_number() -> token_kind {
|
|
lean_assert('0' <= curr() && curr() <= '9');
|
|
mpq q(1);
|
|
m_num_val = curr() - '0';
|
|
next();
|
|
bool is_decimal = false;
|
|
|
|
while (true) {
|
|
char c = curr();
|
|
if ('0' <= c && c <= '9') {
|
|
m_num_val = 10*m_num_val + (c - '0');
|
|
if (is_decimal)
|
|
q *= 10;
|
|
next();
|
|
} else if (c == '.') {
|
|
// Num. is not a decimal. It should be at least Num.0
|
|
if (is_next_digit()) {
|
|
if (is_decimal)
|
|
break;
|
|
is_decimal = true;
|
|
next();
|
|
} else {
|
|
break;
|
|
}
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
if (is_decimal)
|
|
m_num_val /= q;
|
|
return is_decimal ? token_kind::Decimal : token_kind::Numeral;
|
|
}
|
|
|
|
void scanner::read_single_line_comment() {
|
|
while (true) {
|
|
if (curr() == '\n') {
|
|
new_line();
|
|
next();
|
|
return;
|
|
} else if (curr() == EOF) {
|
|
return;
|
|
} else {
|
|
next();
|
|
}
|
|
}
|
|
}
|
|
|
|
// Try to consume str, return true if success.
|
|
// Throw a parser exception error_msg if end of file is found
|
|
bool scanner::consume(char const * str, char const * error_msg) {
|
|
if (curr() == str[0]) {
|
|
next();
|
|
unsigned i = 1;
|
|
while (true) {
|
|
if (!str[i])
|
|
return true;
|
|
check_not_eof(error_msg);
|
|
update_line();
|
|
if (curr_next() != str[i])
|
|
return false;
|
|
i++;
|
|
}
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static char const * g_begin_comment_block = "(--";
|
|
static char const * g_end_comment_block = "--)";
|
|
|
|
void scanner::read_comment_block() {
|
|
static char const * end_error_msg = "unexpected end of comment block";
|
|
unsigned nesting = 1;
|
|
while (true) {
|
|
if (consume(g_begin_comment_block, end_error_msg)) {
|
|
nesting++;
|
|
}
|
|
if (consume(g_end_comment_block, end_error_msg)) {
|
|
nesting--;
|
|
if (nesting == 0)
|
|
return;
|
|
}
|
|
check_not_eof(end_error_msg);
|
|
update_line();
|
|
next();
|
|
}
|
|
}
|
|
|
|
// Read until the end_str is found, store all characters (not including end_str) in m_buffer.
|
|
// Throw a parser exception error_msg if end of file is found before end_str.
|
|
void scanner::read_until(char const * end_str, char const * error_msg) {
|
|
lean_assert(end_str);
|
|
lean_assert(end_str[0]);
|
|
m_buffer.clear();
|
|
while (true) {
|
|
check_not_eof(error_msg);
|
|
update_line();
|
|
char c = curr_next();
|
|
if (c == end_str[0]) {
|
|
m_aux_buffer.clear();
|
|
m_aux_buffer += c;
|
|
unsigned i = 1;
|
|
while (true) {
|
|
if (!end_str[i])
|
|
return;
|
|
check_not_eof(error_msg);
|
|
update_line();
|
|
c = curr_next();
|
|
if (c != end_str[i]) {
|
|
m_buffer += m_aux_buffer;
|
|
break;
|
|
}
|
|
i++;
|
|
}
|
|
} else {
|
|
m_buffer += c;
|
|
}
|
|
}
|
|
}
|
|
|
|
auto scanner::read_script_block() -> token_kind {
|
|
read_until("*)", "unexpected end of script");
|
|
return token_kind::ScriptBlock;
|
|
}
|
|
|
|
static bool is_id_first(char c) { return std::isalpha(c) || c == '_'; }
|
|
static bool is_id_rest(char c) { return std::isalnum(c) || c == '_' || c == '\''; }
|
|
|
|
void scanner::move_back(std::streamoff offset) {
|
|
if (offset != 0) {
|
|
if (curr() == EOF) {
|
|
m_curr = 0;
|
|
m_stream.clear();
|
|
m_spos--;
|
|
}
|
|
m_stream.seekg(offset, std::ios_base::cur);
|
|
m_spos += offset;
|
|
next();
|
|
}
|
|
}
|
|
|
|
bool scanner::is_next_id_rest() {
|
|
lean_assert(curr() != EOF);
|
|
char c = m_stream.get();
|
|
bool r = is_id_rest(c);
|
|
m_stream.unget();
|
|
return r;
|
|
}
|
|
|
|
auto scanner::read_key_cmd_id() -> token_kind {
|
|
static char const * error_msg = "unexpected token";
|
|
char c = curr();
|
|
unsigned num_cs = 1; // number of characters read
|
|
token_table const * it = find(m_tokens, c);
|
|
token_info const * info = nullptr;
|
|
unsigned key_size = 0;
|
|
if (it) {
|
|
info = value_of(*it);
|
|
if (info)
|
|
key_size = 1;
|
|
}
|
|
|
|
std::string & id_part = m_buffer;
|
|
bool is_id = is_id_first(c);
|
|
unsigned id_size = 0;
|
|
if (is_id) {
|
|
m_name_val = name();
|
|
id_part.clear();
|
|
id_part.push_back(c);
|
|
id_size = 1;
|
|
}
|
|
|
|
while (it || is_id) {
|
|
next();
|
|
c = curr();
|
|
if (c != EOF)
|
|
num_cs++;
|
|
|
|
if (is_id) {
|
|
if (is_id_rest(c)) {
|
|
id_part.push_back(c);
|
|
id_size++;
|
|
} else if (c == '.' && is_next_id_rest()) {
|
|
m_name_val = name(m_name_val, id_part.c_str());
|
|
id_size++;
|
|
id_part.clear();
|
|
} else {
|
|
is_id = false;
|
|
m_name_val = name(m_name_val, id_part.c_str());
|
|
if (!it)
|
|
return token_kind::Identifier;
|
|
}
|
|
}
|
|
|
|
if (it) {
|
|
it = find(*it, c);
|
|
if (it) {
|
|
if (auto new_info = value_of(*it)) {
|
|
info = new_info;
|
|
key_size = num_cs;
|
|
}
|
|
} else if (!is_id) {
|
|
if (id_size > key_size) {
|
|
move_back(static_cast<std::streamoff>(id_size) - static_cast<std::streamoff>(num_cs));
|
|
return token_kind::Identifier;
|
|
} else if (info) {
|
|
move_back(static_cast<std::streamoff>(key_size) - static_cast<std::streamoff>(num_cs));
|
|
m_token_info = info;
|
|
return info->is_command() ? token_kind::CommandKeyword : token_kind::Keyword;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
throw_exception(error_msg);
|
|
}
|
|
|
|
static name g_begin_script_tk("(*");
|
|
static name g_begin_comment_tk("--");
|
|
static name g_begin_comment_block_tk("(--");
|
|
|
|
auto scanner::scan() -> token_kind {
|
|
while (true) {
|
|
char c = curr();
|
|
m_pos = m_spos;
|
|
m_line = m_sline;
|
|
switch (c) {
|
|
case ' ': case '\r': case '\t':
|
|
next();
|
|
break;
|
|
case '\n':
|
|
next(); new_line();
|
|
break;
|
|
case '\"':
|
|
return read_string();
|
|
case -1:
|
|
return token_kind::Eof;
|
|
default:
|
|
if (std::isdigit(c)) {
|
|
return read_number();
|
|
} else {
|
|
token_kind k = read_key_cmd_id();
|
|
if (k == token_kind::Keyword) {
|
|
// We treat '(--', '(*', '--' as "keywords.
|
|
name const & n = m_token_info->value();
|
|
if (n == g_begin_comment_tk)
|
|
read_single_line_comment();
|
|
else if (n == g_begin_comment_block_tk)
|
|
read_comment_block();
|
|
else if (n == g_begin_script_tk)
|
|
return read_script_block();
|
|
else
|
|
return k;
|
|
} else {
|
|
return k;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
scanner::scanner(token_table const & tks, std::istream & strm, char const * strm_name):
|
|
m_tokens(tks), m_stream(strm), m_spos(0), m_sline(1), m_curr(0), m_pos(0), m_line(1),
|
|
m_token_info(nullptr) {
|
|
m_stream_name = strm_name ? strm_name : "[unknown]";
|
|
next();
|
|
}
|
|
|
|
std::ostream & operator<<(std::ostream & out, scanner::token_kind k) {
|
|
out << static_cast<unsigned>(k);
|
|
return out;
|
|
}
|
|
}
|