stack.c

#include "stack.h"
#include <inttypes.h>

Stack theStack;

StackError_t init()
{
	if (STACK_SIZE == 0)
		return StackError_t::STACK_INIT_ERROR;

    for( size_t i = 0; i < STACK_SIZE; ++i )
        theStack.data[ i ] = 0;

    theStack.length = 0;

	return StackError_t::STACK_NO_ERROR;
}

StackError_t push(uint8_t value)
{
	if (theStack.length < STACK_SIZE)
	{
		theStack.data[STACK_SIZE - ++theStack.length] = value;
		return StackError_t::STACK_NO_ERROR;
	}
	else
		return StackError_t::STACK_OVERFLOW_ERROR;
}

StackError_t pop( uint8_t* value )
{
	if (theStack.length > 0)
	{
		*value = theStack.data[STACK_SIZE - theStack.length--];
		return StackError_t::STACK_NO_ERROR;
	}
	else
		return StackError_t::STACK_UNDERFLOW_ERROR;
}

StackError_t peek(const uint8_t* index)
{
	for (size_t i = 0; i < theStack.length; ++i)
		if (theStack.data[i] == *index)
			return StackError_t::STACK_NO_ERROR;

	return StackError_t::STACK_VALUE_NOT_FOUND;
}

bool isEmpty()
{
	if (theStack.length == 0)
		return true;

	return false;
}

bool isFull()
{
	if (theStack.length == STACK_SIZE)
		return true;

	return false;
}