srinathmp / generics-in-c

Generic Containers in C

C programming language does not provide templates which are commonly used for generic container data types in other statically typed programming languages. This feature however can be implemented in C by the use of macros.

C macros have been extensively used in implementing generic containers. This repository contains implementation of generic list in C language.

List

Lists are sequence containers that allow for non contiguous memory allocation.
The library provides a generic list container that is compatible with standard types as well as user defined types.
The internal implementation uses a singly linked list.

Methods

Function	Description
gl_init	initializes the list with user provided type
gl_size	returns the number of elements
gl_find	returns iterator to the element if found
gl_push_back	adds an element to the end
gl_pop_back	removes the last element
gl_push_front	inserts an element to the beginning
gl_pop_front	removes the first element
gl_remove	removes all occurences of the given element
gl_clear	clears the contents
gl_sort	sorts the elements (uses merge sort)
gl_iterator	iterator for given type
gl_init_iterator	initialise the iterator to given list
gl_iterator_eq	compare two iterators
gl_begin	iterator to the beginning of container
gl_end	iterator to one past the end of container

Usage

#include <stdio.h>
#include "glist.h"

glist(int) intlist;

int main()
{
	intlist l = gl_init(int); // []

	gl_push_front(l, 4);	// [4]
	gl_push_back(l, 3); 	// [4, 3]
	gl_push_back(l, 1);	// [4, 3, 1]
	gl_push_back(l, 2);	// [4, 3, 1, 2]
	gl_push_front(l, 4);	// [4, 4, 3, 1, 2]
	
	gl_remove(l, 4);	// [3, 1, 2]

	gl_sort(l);		// [1, 2, 3]

	gl_iterator(int) it;
	gl_init_iterator(int, one, &it);
	
	while(has_next(&it))
	{
		printf("%d ", next(&it));	// 1 2 3
	}
}