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#include "utils.h"
#include "exceptions.h"
#include "tree.h"
namespace SimpleParser {
int8_t getPriority(char tmp) {
switch ( tmp ) {
case '-':
return 10;
case '+':
return 10;
case '/':
return 20;
case '*':
return 20;
case '^':
return 30;
case '(':
return 90;
case ')':
return 90;
case ',':
return -1;
default:
return -1;
}
}
std::vector<std::string> lexer(std::string term) {
std::string tmp;
std::string tmpNum;
std::vector<std::string> output;
int8_t priority = 0;
int8_t lastPriority = 0;
uint32_t level = 0;
for ( auto termIter = term.begin();
termIter != term.end();
termIter++ ) {
priority = getPriority(*termIter);
if ( priority == -1 || ( termIter == term.begin() &&
priority == 10 ) ) {
if ( level > 0 ) {
tmp += *termIter;
} else {
tmpNum += *termIter;
}
} else {
if ( lastPriority == -1 && level == 0 ) {
output.push_back(tmpNum);
tmpNum.clear();
}
switch ( *termIter ) {
case '(': {
if ( level > 0 ) {
tmp += *termIter;
}
level++;
break;
}
case ')': {
level--;
if ( level == 0 ) {
output.push_back(tmp);
tmp.clear();
} else {
tmp += *termIter;
}
break;
}
default: {
if ( level == 0 ) {
std::string helper;
helper = *termIter;
output.push_back(helper);
} else {
tmp += *termIter;
}
break;
}
}
}
lastPriority = priority;
}
if ( lastPriority == -1 ) {
output.push_back(tmpNum);
} else if ( lastPriority != 90 ) {
throw operator_exception();
}
if (level != 0) {
throw parenthese_exception();
}
if ( lastPriority == 90 && output.size() == 1 ) {
output = lexer(output[0]);
}
return output;
}
}
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