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#include <string>
#include <array>
#include "include/tokenizer.hpp"
#include "exceptions/tokenizer_exception.hpp"
Tokenizer::Tokenizer() {
tokens.fill(nullptr);
tokens_head = 0;
}
Tokenizer::~Tokenizer() {
clearTokens();
}
void Tokenizer::clearTokens() {
for(auto token{ tokens.begin() }; *token != nullptr; ++token)
delete token;
tokens.fill(nullptr);
}
void Tokenizer::insertToken(Type type, int value = 0) {
Token *new_token = new Token { .type = type, .value = value};
tokens[tokens_head] = new_token;
tokens_head += 1;
}
const std::array<Token *, 16>
&Tokenizer::tokenize(const std::string &operation) {
to_tokenize = &operation;
current_char_index = 0;
while(current_char_index < operation.length()) {
size_t unchanged_index = current_char_index;
matchOperand(operation);
matchParens(operation);
matchOperation(operation);
// No matches.
if(unchanged_index == current_char_index)
throw TokenizerException("Invalid character detected.");
}
return getTokens();
}
void Tokenizer::matchOperand(const std::string &operation) {
std::smatch match;
if(current_char_index > operation.length())
return;
std::string remaining(operation.substr(current_char_index));
bool result = std::regex_search(remaining, match,
operand_regex);
if(!result)
return;
insertToken(operand, std::stoi(match.str(0)));
current_char_index += match.length(0);
}
void Tokenizer::matchParens(const std::string &operation) {
std::smatch match;
if(current_char_index > operation.length())
return;
std::string remaining(operation.substr(current_char_index));
bool result = std::regex_search(remaining, match,
operand_regex);
if(!result)
return;
switch(match.str(0)[0]) {
case '(':
insertToken(left_parens);
break;
case ')':
insertToken(right_parens);
break;
}
current_char_index += 1;
}
void Tokenizer::matchOperation(const std::string &operation) {
std::smatch match;
if(current_char_index > operation.length())
return;
std::string remaining(operation.substr(current_char_index));
bool result = std::regex_search(remaining, match,
operand_regex);
if(!result)
return;
switch(match.str(0)[0]) {
case '+':
insertToken(sum);
break;
case '-':
insertToken(substraction);
break;
case '*':
insertToken(multiplication);
break;
case '/':
insertToken(division);
break;
}
current_char_index += 1;
}
const std::array<Token *, 16> &Tokenizer::getTokens() {
return tokens;
}
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