ChaiScript/langkit/langkit_lexer.cpp
2009-05-27 15:07:29 +00:00

85 lines
2.9 KiB
C++

// This file is distributed under the BSD License.
// See LICENSE.TXT for details.
#include <iostream>
#include "langkit_lexer.hpp"
Lexer Lexer::operator<<(const Pattern &p) {
lex_patterns.push_back(p);
return *this;
}
std::vector<TokenPtr> Lexer::lex(const std::string &input, const char *filename) {
std::vector<Pattern>::iterator iter, end;
std::vector<TokenPtr> retval;
bool found;
std::string::const_iterator input_iter = input.begin();
int current_col = 0;
int current_line = 0;
while (input_iter != input.end()) {
found = false;
for (iter = lex_patterns.begin(), end = lex_patterns.end(); iter != end; ++iter) {
boost::match_results<std::string::const_iterator> what;
if (regex_search(input_iter, input.end(), what, iter->regex, boost::match_continuous)) {
TokenPtr t(new Token(what[0], iter->identifier, filename));
t->start.column = current_col;
t->start.line = current_line;
current_col += t->text.size();
t->end.column = current_col;
t->end.line = current_line;
retval.push_back(t);
input_iter += t->text.size();
found = true;
break;
}
}
if (!found) {
for (iter = skip_patterns.begin(), end = skip_patterns.end(); iter != end; ++iter) {
boost::match_results<std::string::const_iterator> what;
if (regex_search(input_iter, input.end(), what, iter->regex, boost::match_continuous)) {
std::string whitespace(what[0]);
input_iter += whitespace.size();
current_col += whitespace.size();
found = true;
break;
}
}
if (!found) {
for (iter = line_sep_patterns.begin(), end = line_sep_patterns.end(); iter != end; ++iter) {
boost::match_results<std::string::const_iterator> what;
if (regex_search(input_iter, input.end(), what, iter->regex, boost::match_continuous)) {
std::string cr(what[0]);
input_iter += cr.size();
found = true;
++current_line;
current_col = 0;
break;
}
}
if (!found) {
const std::string err(input_iter, input.end());
std::cout << "Unknown string at: " << err << std::endl;
return retval;
}
}
}
}
return retval;
}
void Lexer::set_skip(const Pattern &p) {
skip_patterns.push_back(p);
}
void Lexer::set_line_sep(const Pattern &p) {
line_sep_patterns.push_back(p);
}
void Lexer::set_command_sep(const Pattern &p) {
command_sep_patterns.push_back(p);
}