stack.c

/*
CS3500 - Software Engineering Project
Calculator using - Tokenizer, infix2postfix, code generator, VM
codegenerator.c

Karol Przestrzelski
Colin Kelleher
Jonathan Hanley
Liam de la Cour
*/

#include <stdlib.h>
#include <stdio.h>
#include "stack.h"

/*
Create new float stack
*/
fstack *FStack(){
    fstack *s = (fstack *)malloc(sizeof(fstack));
    s->list[s->size];
    s->currentPosition = -1;
    return s;
}

/*
Pop first element off FStack
If the stack is empty, return 0
*/
float pop(fstack *f){
    if (f->currentPosition == -1)
        return 0;
    return f->list[f->currentPosition--];
}
/*
Push new item onto stack
*/
void push(fstack *f, float item){
    f->list[++f->currentPosition] = item;
}
/*
Get length of stack
*/
int len(fstack *f){
    if (f->currentPosition == -1)
        return 0;
    return f->currentPosition + 1;
}