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regex.cpp
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regex.cpp
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/*
Copyright (c) 2009 Andrew Caudwell (acaudwell@gmail.com)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "regex.h"
Regex::Regex(std::string regex, bool test) {
int errornumber;
PCRE2_SIZE erroroffset;
re = pcre2_compile(
(PCRE2_SPTR) regex.c_str(),
regex.size(),
0,
&errornumber,
&erroroffset,
NULL
);
if(!re) {
valid = false;
if(!test) {
throw RegexCompilationException(regex);
}
} else {
valid = true;
}
}
Regex::Regex(const Regex& regex) {
if(regex.isValid()) {
re = pcre2_code_copy(regex.re);
valid = true;
} else {
re = 0;
valid = false;
}
}
Regex::~Regex() {
if(re != 0) pcre2_code_free(re);
}
bool Regex::isValid() const {
return valid;
}
bool Regex::replace(std::string& str, const std::string& replacement_str) {
int offset = replaceOffset(str, replacement_str, 0);
return (offset != -1);
}
bool Regex::replaceAll(std::string& str, const std::string& replacement_str) {
int offset = -1;
while((offset = replaceOffset(str, replacement_str, offset+1)) != -1 && offset < str.size());
return (offset != -1);
}
int Regex::replaceOffset(std::string& str, const std::string& replacement_str, int offset) {
pcre2_match_data* match_data = pcre2_match_data_create_from_pattern(re, NULL);
int rc = pcre2_match(
re,
(PCRE2_SPTR) str.c_str(),
str.size(),
offset,
0,
match_data,
NULL
);
//failed match
if(rc<1) {
pcre2_match_data_free(match_data);
return -1;
}
PCRE2_SIZE* ovector = pcre2_get_ovector_pointer(match_data);
// replace matched section of string
std::string new_str = str;
new_str.replace(ovector[0], ovector[1]-ovector[0], replacement_str);
size_t end_offset = ovector[0] + replacement_str.size();
for (int i = 1; i < rc; i++) {
int match_start = ovector[2*i];
int match_end = ovector[2*i+1];
std::string matched_str;
if(match_start != -1) {
matched_str = std::string(str, match_start, match_end-match_start);
}
// check if 'str' contains $i, if it does, replace with match string
size_t string_size = new_str.size();
for(size_t j=0; j<string_size-1; j++) {
if(new_str[j] == '$' && atoi(&(new_str[j+1])) == i) {
new_str.replace(j, 2, matched_str);
size_t new_string_size = new_str.size();
end_offset += (new_string_size-string_size);
string_size = new_string_size;
}
}
}
str = new_str;
pcre2_match_data_free(match_data);
return end_offset;
}
bool Regex::match(const std::string& str, std::vector<std::string>* results) {
if(results != 0) results->clear();
int offset = matchOffset(str, results, 0);
return offset != -1;
}
bool Regex::matchAll(const std::string& str, std::vector<std::string>* results) {
int offset = 0;
int match_count = 0;
if(results != 0) results->clear();
int str_size = str.size();
while((offset = matchOffset(str, results, offset)) != -1) {
match_count++;
if(offset >= str_size) break;
}
return match_count > 0;
}
int Regex::matchOffset(const std::string& str, std::vector<std::string>* results, int offset) {
if(offset >= str.size()) return -1;
pcre2_match_data* match_data = pcre2_match_data_create_from_pattern(re, NULL);
int rc = pcre2_match(
re,
// To allow ^ to match the start of the remaining string
// offset the string before passing it
(PCRE2_SPTR)(str.c_str() + offset),
str.size() - offset,
0,
0,
match_data,
NULL
);
//failed match
if(rc < 1) {
pcre2_match_data_free(match_data);
return -1;
}
PCRE2_SIZE* ovector = pcre2_get_ovector_pointer(match_data);
if(results != 0) {
for (int i = 1; i < rc; i++) {
int match_start = ovector[2*i];
int match_end = ovector[2*i+1];
// insert a empty string for non-matching optional regex
if(match_start == -1) {
results->push_back(std::string(""));
} else {
std::string match(str, match_start+offset, match_end-match_start);
results->push_back(match);
}
}
}
int result_offset = ovector[1] + offset;
pcre2_match_data_free(match_data);
return result_offset;
}