notes.cpp

#include "arithmetic_utilities.h"
#include <cstdlib>

// Honestly kinda not seeing why most of these helper functions are a thing if
// they're all one liners. Most C++ codebases avoid that since the overhead of
// calling functions is huge compared to just writing the oneliner.

/**
 * convert char array into a number using the atoi
 * @param char* arr
 * @return int
 */
int Helper::getNum(char* arr){
    int num = atoi(arr);
    return num;
}

/**
 * Checks to see if the current char is a valid Digit or not
 * @param char c
 * @return bool
 */
bool Helper::isValidDig(char c){
    return (c >= '0' && c <= '9')
}

/**
 *
 * The only time that we will have a negative number when parsing + and * is when
 * - is the first element after +, * or (, otherwise it will be negative
 */
bool Helper::isNeg(std::vector<char>& vec, int pos){ // why pos instead of idx?
    // Many programmers stylistically prefer to do early returns to keep indenting levels low
    if (vec[pos] != '-') {
        return false;
    }
    
    //Check to see if we are looking at the first element of the char array
    // (less than equal instead of == to make sure you can't pass in a negative number?)
    if(pos <= 0) {
        return true;
    }
    
    auto token = vec[pos-1];
    return (token == '*' || token == '+' || token == '('
}

//check to see that the section of the vector we are working is a multiplication
bool Helper::isMult(std::vector<char>& vec, int pos){
    return vec[pos] == '*';
}


bool Helper::isAdd(std::vector<char>& vec, int pos){
    return vec[pos] == '+';
}