Introduction

Easy to use, modular, header only, macro based, generic and type-safe Data Structures in C

The C Macro Collections Library is a compilation of macros that can be used to generate common data structures for any desired type. These data structures are type safe and are powered with many features (see Features section).

The documentation is currently being written in hopes that in the future it can be used to help you get to know better this amazing C library.

Why this library

C is a low level language and lacks all the data structures that we commonly use. Many high level languages already come with these collections so that we don't have to implement everything ourselves. A lot of third party libraries that implement these missing data structures for the C language usually make use of a void pointers and a lot of macros. This is why the C Macro Collections Library was created. All you need to do is to write down one macro and which data type you wish to work with. The library currently provides many data structures, such as:

• Linear Collections : List, LinkedList, Deque, Stack, Queue, SortedList
• Sets : HashSet, TreeSet, MultiSet
• Maps : HashMap, TreeMap, MultiMap, BidiMap
• Heaps : Heap, IntervalHeap

All with the following features:

• Type-safe - No void * pointers are used. A collection of type int will only accept integers;
• Customization - Custom struct name and function namespace;
• Bidirectional Iterators - Full support for iterators;
• Nesting - Collections can be nested (List of Lists, HashSet of Stacks, etc);
• One macro to rule them all - Only one macro to generate everything and that's it.

and many other powerful features (see Features).

How to install

To start using the library you need first to download the source code. You can either fork the repository or download a zip file containing everything. Either way, after you unzip everything you will end up with the root folder (probably something called C-Macro-Collections) and inside it is the src folder.

With the src folder you can start including the library headers to your project with -I path/to/library/src.

The library has no external dependencies other than the C standard library.

// Include header files like this
#include <cmc/list.h>
#include <dev/deque.h>
#include <utl/assert.h>

// Not like this
#include <list.h>
#include <deque.h>  // dev or cmc?
#include <assert.h> // this will import from the standard library

Library Structure

The src folder is subdivided in 5 other folders and one file:

• cmc - The main C Macro Collections Library
• dev - The main C Macro Collections Library for development
• sac - Statically Allocated Collections
• utl - Utility like ForEach macros, logging, etc
• macro_collections.h - Master header containing all collections and utilities

cmc

This is where the C Macro Collections are hosted.

dev

In this folder is an exact copy of the cmc Collections with the added logging utility (./utl/log.h). These are useful to debug your code because everything that is happening inside the data structure can be seen.

sac

This is where the Statically Allocated Collections are hosted. These collections are just like the cmc Collections but they have a constant size, a C array, instead of a dynamically allocated array (yes, even for Linked List).

utl

Utility. Here you will find things like assert macros, foreach macros, logging utility, unit test and timer.

macro_collections.h

This is the master header. Include this big boy and all functionalities of the library will be in your hands.

Understanding the Library

Every macro within the library is prefixed by CMC or cmc. If you have intellisense you can easily check all the features of the library once you include the necessary headers.

When you generate code for a certain collection you will need to pass four very important parameters: SNAME, PFX, K and V.

SNAME

SNAME is short for struct name. This parameter will define your collection so that its type name becomes:

struct SNAME;

No typedefs are used within the code that is generated in order to not pollute the global namespace. If you wish to typedef feel free to give your own naming conventions. Every other struct that is generated as part of the implementation will be prefixed by SNAME. So iterators and nodes will become:

struct SNAME##_iter;
struct SNAME##_node;

Note that the ## is a Token Pasting Operator.

PFX

PFX is a short for prefix. Every function generated will be within this namespace. When using Intellisense, write whichever prefix you gave to your functions and everything will be in there.

Functions that are part of the implementation and shouldn't be called directly are prefixed by PFX and then by _impl_. Every iterator function will be prefixed by PFX and then by _iter_. For example:

// A function that you shouldn't use directly
size_t PFX##_impl_quick_sort(struct SNAME *list);

// A function that is associated with the iterator
struct SNAME##_iter *PFX##_iter_new(struct SNAME *target);

K

K, short for Key, is the data type that is only used by associative collections to map a key to a value.

V

V, short for Value, is the primary data type for most collections.

Summarizing

With SNAME and PFX a common function definition looks like:

size_t PFX##_count(struct SNAME *list);

So if input SNAME as i32list and PFX as i32l you will have the following function definition:

size_t i32l_count(struct i32list *list);

How to Use the Library

The C Macro Collections Library comes with very powerful data structures and they are only one macro away from you.

TODO

Overview

In this section you will be able to quickly glance at what are the core functionalities that the C Macro Collections library can bring you.

Collections Overview

Features Overview

The C Macro Collections library comes with some core features available to all collections.

Files Overview

An overview of the source files (all .h) of the C Macro Collections library.

• cmc - The main C Macro Collections library
• cor - Core functionalities of the C Macro Collections libraries
  • core.h - Core functionalities of the library
  • hashtable.h - Common things used by hash table based collections
• utl - Utilities
  • assert.h - Non-abortive assert macros
  • foreach.h - For Each macros
  • futils.h - Common functions used by Functions Table
  • log.h - Logging utility with levels of severity
  • test.h - Simple Unit Test building with macros
  • test.h - Timing code execution utility
• bidimap.h - A bi-directional map based on a hash table
• deque.h - A double-ended queue
• hashmap.h - A map based on a hash table
• hashset.h - A set based on a hash table
• heap.h - A binary heap based on a dynamic array
• intervalheap.h - A heap that is both Min and Max based on a dynamic array
• linkedlist.h - A doubly-linked list
• list.h - A dynamic array
• multimap.h - A map that accepts multiple keys based on a hash table
• multiset.h - A multiset based on a hash table
• queue.h - A FIFO based on a circular dynamic array
• sortedlist.h - A sorted list based on a dynamic array
• stack.h - A LIFO based on a dynamic array
• treemap.h - A sorted map based on an AVL tree
• treeset.h - A sorted set based on an AVL tree

COR

Core functionalities of the C Macro Collections Library.

Callbacks

Every collection can have an optional callback node. In this node there are five functions:

Check the documentation for each collection to see which functions call which callbacks.

cmc_callbacks

Every collection has a pointer to this struct. If it is NULL then the collection has no callbacks. Also, individual callbacks can be optional if set to NULL.

struct cmc_callbacks
{
    void (*create)(void);
    void (*read)(void);
    void (*update)(void);
    void (*delete)(void);
    void (*resize)(void);
};

Example

#include "cmc/heap.h"
#include "utl/futils.h" // cmc_i32_cmp

// Generate a heap of integers
CMC_GENERATE_HEAP(i32h, i32heap, int)

void heap_on_create(void)
{
    printf("An element was added to the heap\n");
}

int main(void)
{
    // create() is set but the other callbacks are not
    struct cmc_callbacks my_callbacks = { .create = heap_on_create, NULL };

    // Create a max heap with the callbacks
    struct i32heap *heap = i32h_new_custom(
        100, cmc_max_heap, &(struct i32heap_fval){ .cmp = cmc_i32_cmp }, NULL,
        &my_callbacks);

    i32h_insert(heap, 10);
    i32h_insert(heap, 11);
    i32h_insert(heap, 12);

    i32h_free(heap);
}

Custom Allocation

All collections have an allocation node. This node can be modified so that every allocation and de-allocation can be done with custom functions. Every custom allocation function must follow the same prototype of the stdlib.h functions.

cmc_alloc_node

struct cmc_alloc_node
{
    void *(*malloc)(size_t);
    void *(*calloc)(size_t, size_t);
    void *(*realloc)(void *, size_t);
    void (*free)(void *);
};

cmc_alloc_node_default

The default allocation node. If a collections is not initialized with a custom allocation node, this will be the default one using the functions from the C standard library.

static struct cmc_alloc_node cmc_alloc_node_default = { malloc, calloc,
                                                        realloc, free };

Example

#include "cmc/heap.h"
#include "utl/futils.h" // cmc_i32_cmp

// Total bytes allocated
size_t total = 0;

void *my_malloc(size_t size)
{
    void *result = malloc(size);

    if (!result)
        return result;

    total += size;
    return result;
}

void *my_calloc(size_t count, size_t size)
{
    void *result = calloc(count, size);

    if (!result)
        return result;

    total += count * size;
    return result;
}

void *my_realloc(void *block, size_t size)
{
    void *result = realloc(block, size);

    if (!result)
        return result;

    total += size;
    return result;
}

// Generate a heap of integers
CMC_GENERATE_HEAP(i32h, i32heap, int)

int main(void)
{
    // My custom allocation node
    struct cmc_alloc_node node = { .malloc = my_malloc,
                                   .calloc = my_calloc,
                                   .realloc = my_realloc,
                                   .free = free };

    // Create a max heap with the custom allocation node
    struct i32heap *heap = i32h_new_custom(
        100, cmc_max_heap, &(struct i32heap_fval){ .cmp = cmc_i32_cmp }, &node,
        NULL);

    for (int i = 0; i < 100000; i++)
        i32h_insert(heap, i);

    i32h_free(heap);

    printf("Total bytes allocated : %" PRIuMAX "\n", total);
}

Error Codes

Error codes are ways to signal errors or success. It is accessed through the flag component of a struct or through a function that is present in every collection:

int PFX##_flag(struct SNAME *_collection_);

Some functions have a return type of bool indicating if it exited successfully or not. These error codes can be used for further error handling.

cmc_flags

It is a global struct with default values for error codes.

static struct
{
    int OK;
    int ALLOC;
    int EMPTY;
    int NOT_FOUND;
    int INVALID;
    int RANGE;
    int DUPLICATE;
    int ERROR;
} cmc_flags = { 0, 1, 2, 3, 4, 5, 6, 7 };

• OK - No errors. The operation exited successfully.
• ALLOC - Allocation failed.
• EMPTY - The collection is empty when it shouldn't.
• NOT_FOUND - Key or value not found.
• INVALID - Invalid argument or operation given the collection's state
• RANGE - Index out of range.
• DUPLICATE - Duplicate key or value.
• ERROR - Generic error. Usually caused by algorithm errors.

cmc_flags_to_str

Maps the integer representation of error codes to their character representation.

const char *cmc_flags_to_str[8] = { "OK",        "ALLOC",   "EMPTY",
                                    "NOT_FOUND", "INVALID", "RANGE",
                                    "DUPLICATE", "ERROR" };

Example

#include "cmc/treeset.h"
#include "utl/futils.h" // cmc_i32_cmp

// Generate a sorted set of integers
CMC_GENERATE_TREESET(tset, sortedset, int)

int main(void)
{
    struct sortedset *set =
        tset_new(&(struct sortedset_fval){ .cmp = cmc_i32_cmp });

    if (!tset_insert(set, 10))
        printf("Error! %s\n", cmc_flags_to_str[tset_flag(set)]);

    if (!tset_insert(set, 10))
        printf("Error! %s\n", cmc_flags_to_str[tset_flag(set)]);

    if (!tset_remove(set, 10))
        printf("Error! %s\n", cmc_flags_to_str[tset_flag(set)]);

    if (!tset_remove(set, 10))
        printf("Error! %s\n", cmc_flags_to_str[tset_flag(set)]);

    tset_free(set);
}

Functions Table

Functions Table is a struct with function pointers that are used to extract behavior from a custom data type. This exists because an int or a char * or struct my_data_type don't have default hash functions or ways to compare between them. This could be achieved with operator overloading but C doesn't have that. Hence, Functions Table was created to provide a single access point to extract these behaviors for any data type.

Some functions are optional and others are needed in order for a collection to operate. Say you want a HashMap. There are two required functions: hash and cmp (comparator). Without them it is impossible to know how to hash your custom that type (it could be anything). This means you can also customize the collection by using different hash functions.

Many required functions are simply mundane. Like a comparator function between integers or between floats. The header utl/futils.h defines many of these functions for basic C data types.

Some collections generate two functions table. One for K and one for V (maps). Others simply generate one for V. A Functions Table struct is always going to be called:

• struct SNAME##_fkey for the K type
• struct SNAME##_fval for the V type

Their definition is defined as follows:

                                     \
struct SNAME##_fkey                  \
{                                    \
    /* Comparator function */        \
    int (*cmp)(K, K);                \
                                     \
    /* Copy function */              \
    K (*cpy)(K);                     \
                                     \
    /* To string function */         \
    bool (*str)(FILE *, K);          \
                                     \
    /* Free from memory function */  \
    void (*free)(K);                 \
                                     \
    /* Hash function */              \
    size_t (*hash)(K);               \
                                     \
    /* Priority function */          \
    int (*pri)(K, K);                \
};                                   \
                                     \

CMP

• K - int (*cmp)(K, K)
• V - int (*cmp)(V, V)

A comparator function is used in sorted collections or when an equality is being checked like when trying to find a certain element in a list. It is responsible for taking two arguments of the same data type and comparing them. The return value is an int with the following definitions:

• Return 1 if the first argument is greater than the second;
• Return 0 if the first argument equals the second;
• Return -1 if the first argument is less than the second.

Note that certain collections require a total ordering of its elements (sorted collections) while others only require to know if one data equals another. Check out the documentation for each collection to know more.

CPY

• K - K (*cpy)(K)
• V - V (*cpy)(V)

A copy function is used when a collection is being copied. It can be used to make a deep copy of of your custom data type. It must take a single parameter and return a new copy of that same data type. If this function is absent (NULL) the data type will be copied by assignment (for pointers this is a shallow copy).

Note that it doesn't makes sense to define a cpy function for data types that are not pointers. This function is useful for deep copies of a pointer in case you don't want two collections holding the same reference to the data.

STR

• K - bool (*str)(FILE *, K)
• V - bool (*str)(FILE *, V)

A string function is responsible for taking a FILE pointer and a custom data type and outputting the string representation of that data returning a bool indication success or failure. It is useful for debugging and doesn't necessarily needs to print all the data that the specific type holds.

FREE

• K - void (*free)(K)
• V - void (*free)(V)

The free function is called when a collection is cleared (all elements removed) or freed (all elements removed and the collection is freed from memory) and it is responsible for completely freeing all resources that are usually acquired by your data type.

This function only makes sense to be used when the data type has dynamically allocated memory. It is the only completely optional function.

HASH

• K - size_t (*hash)(K)
• V - size_t (*hash)(V)

This function receives a custom data type as parameter and returns a size_t hash that represents that data. Used by collections with an underlying hash tables.

PRI

• K - int (*cmp)(K, K)
• V - int (*cmp)(V, V)

A priority function works much like the comparator function except that it compares the priority between two elements. It is used in collections whose structure is based on the priority of elements and not in their general comparison (heaps).

• Return 1 if the first argument has a greater priority than the second;
• Return 0 if the first argument has the same priority as second;
• Return -1 if the first argument has a lower priority than the second.

Why use both cmp and pri? Heaps have their internal structure based in the priority of elements. This priority is not necessarily how each element is compared to each other. Maybe their equality is defined differently for an equality of priorities. Maybe the rules for their priorities is different for when comparing an element against another.

The following table shows which functions are required, optional or never used for each Collection:

Collection	CMP	CPY	STR	FREE	HASH	PRI
BidiMap
Deque
HashMap
HashSet
Heap
IntervalHeap
List
LinkedList
MultiMap
MultiSet
Queue
SortedList
Stack
TreeMap
TreeSet

Color	Label
	Required for basic functionality.
	Required for specific functions.
	Required for non-core specific functions.
	Optional.
	Not Used.

Iterators

Every collection comes with an interface of iterators where you can easily access the elements of a collection. These can move at any direction, can start at any 'end' of a collection and can move any amount of steps per iteration. Every collection generated comes with an iterator.

By design choice these iterators do not support modifications to the collection. If a collection is modified, all iterators that have been initialized will most likely be invalidated and may cause undefined behavior if used afterwards.

CMC

The main C Macro Collections.

The C Macro Collections library was created out of necessity. To create powerful data structures of any type without the constant use of macros and void * pointers, but at the same time being type-safe. These collections are generated by macros containing a template. These templates allow for some much needed customizations including the data type you wish to handle.

In the cmc folder is the default implementation of all collections. There is also a dev folder that pretty much has the same macros that expand to the same code, except that they have an extensive use of logging that might be useful for debugging or getting to know what is happening in your program. There is also the sac collections that are statically allocated (have a fixed sized buffer).

Quick Example

Let's say you need a HashMap mapping keys of type char * to int. All you need to do is:

#include "cmc/hashmap"

// CMC_GENERATE_HASHMAP(PFX, SNAME, K, V)
CMC_GENERATE_HASHMAP(map, hashmap, char *, int)

int main(void)
{
    // Here you have full functionalities of a HashMap
    // No more macros needed!
    // Every function can be found in the 'map_' prefix and are all type-safe
}

You can customize the functions prefix (PFX) and the struct name (SNAME). The macro CMC_GENERATE_HASHMAP will expand to all the code that you will need to operate on a HashMap with char * keys and int values. The only thing left to do is to define a hash function and a comparator functions for the keys of this map. In case of char * you can find these functions in utl/futils.h or make your own. To know which collections require which functions check out Functions Table or the documentation for each collection.

bitset.h

A Bit Set is an array where each bit can be individually modified and queried by using bitwise operators such as |, &, ^, ~, >> and << (or, and, xor, not, right shift, left shift respectively).

BitSet Implementation

This BitSet implementation uses an array of type cmc_bitset_word which can be typedefed to any unsigned type such as uint8_t, uint16_t, uint32_t, uint64_t, size_t, etc. The BitSet does not make use of K or V. Because of that, it also doesn't have Functions Tables.

The BitSet is initialized with a custom capacity but, if a bit index accessed is greater than the total capacity, the BitSet will resize. This means that the BitSet will try to guarantee that every bit index is accessible, as long as there is enough memory.

BitSet Generation Macros

• CMC_GENERATE_BITSET(PFX, SNAME) - Generate full definition.
• CMC_GENERATE_BITSET_HEADER(PFX, SNAME) - Generate only the header portion
• CMC_GENERATE_BITSET_SOURCE(PFX, SNAME) - Generate only the source portion

BitSet Structures

struct SNAME

struct SNAME##_iter

cmc_bitset_word

The typedefed data type o the underlying bit set buffer.

typedef uint32_t cmc_bitset_word;

This typedef can be changed to any unsigned integer data type and the bit set will still work properly.

Callbacks

This list associates which functions calls which callbacks.

• create
  • PFX##_set()
  • PFX##_set_range()
• read
• update
• delete
  • PFX##_clear()
  • PFX##_clear_range()
• resize
  • PFX##_resize()

Functions Table

CMP	CPY	STR	FREE	HASH	PRI

deque.h

A Deque, also known as a double-ended queue, is a linear data structure that is able to add and remove elements from both ends. It can also be thought of a double-ended stack since you can push and pop elements from two ends. The Deque can also be used as a Queue. The only elements accessible from a Deque ar the two elements at its ends (front element and back element).

Deque Implementation

This implementation uses a circular buffer (ring buffer or cyclic buffer) in order to operate on O(1) for push and pop on either ends. The only case where it takes longer than O(1) is when the buffer is reallocated. If it was implemented as a regular array, adding or removing elements from the front would take O(N) due to the need to shift all elements in the Deque.

Two indices are kept track of. The front index and the rear index. These represent the both ends of the Deque. If an index reaches one end of the real buffer, they wrap around to the other end and an element is added there. This abstracts the real buffer as a circular buffer with the cost os constantly checking for boundaries and using the modulo operator.

Deque Generation Macros

• CMC_GENERATE_DEQUE(PFX, SNAME, V) - Generate full definition.
• CMC_GENERATE_DEQUE_HEADER(PFX, SNAME, V) - Generate only the header portion
• CMC_GENERATE_DEQUE_SOURCE(PFX, SNAME, V) - Generate only the source portion

Deque Structures

struct SNAME

struct SNAME##_fval

The Functions Table for V. Check out the Functions Table documentation here.

struct SNAME##_iter

Callbacks

This list associates which functions calls which callbacks.

• create
  • PFX##_push_front()
  • PFX##_push_back()
• read
  • PFX##_front()
  • PFX##_back()
  • PFX##_contains()
• update
• delete
  • PFX##_pop_front()
  • PFX##_pop_back()
• resize
  • PFX##_resize()

Functions Table

CMP	CPY	STR	FREE	HASH	PRI

Index

Deque

• _new()
• _new_custom()
• _clear()
• _free()
• _customize()
• _push_front()
• _push_back()
• _pop_front()
• _front()
• _back()
• _contains()
• _empty()
• _full()
• _count()
• _capacity()
• _flag()
• _resize()
• _copy_of()
• _equals()
• _to_string()
• _print()

Deque Iterator

WIP.

_new()

Allocates on the heap and returns a new Deque with an internal capacity of the specified value. The Deque will be empty, using the default allocator cmc_alloc_node_default and no callbacks will be set, that is, callbacks will be set to NULL. Its flag will be initially cmc_flags.OK.

Declaration

struct SNAME *PFX##_new(size_t capacity, struct SNAME##_fval *f_val);

Parameters

Returns

_new_custom()

Like _new() but allows for custom allocation node and callbacks. The allocation node is optional. If present, the function will immediately use it to allocate the new Deque. If NULL, cmc_alloc_node_default will instead be used.

Declaration

struct SNAME *PFX##_new_custom(size_t capacity, struct SNAME##_fval *f_val, struct cmc_alloc_node *alloc, struct cmc_callbacks *callbacks);

Parameters

Returns

DEV

The development collections. These collections are an exact copy of the cmc collections but they come with many logging throughout the generated code. Useful for debugging or during development.

SAC

The Statically Allocated Collections. These collections have a fixed size. Its size is one of the parameters during macro expansion, producing a C array.

CMC vs. SAC

The cmc collections hold their data either with nodes or a buffer that can be reallocated. The sac collections only have an array with fixed size and don't perform any allocation on the heap.

// A CMC List
struct List
{
    T *buffer;
    /* Other fields */
};

// A SAC List
struct List
{
    T buffer[SIZE];
    /* Other fields */
};

UTL

Inside the ./utl/ folder there are many utility functions and macros that can be extensively used with the C Macro Collections library. Most of these utilities can be used without the main library.

Contents

• assert.h - Non-abortive assert macros
• foreach.h - For Each macros
• futils.h - Common functions used by Functions Table
• log.h - Logging utility with levels of severity
• test.h - Simple Unit Test building with macros
• timer.h - Timing code execution utility

assert.h

Definition of many typed non-abortive assertions. Every assertion that fails will print a message to stderr but will not abort the program execution. The macro parameters are first assigned to a temporary variable of the specified dtype in order to generate warnings from the compiler in case of type mismatch.

The advantage of these typed macros is that when an assertion fails, it is possible to print to stderr the actual value that was passed to the function and check the expected result(s) all in one message.

There are assertions that work with predefined values and others that work with generic values. Valued assertions work with a selected list of dtype (see further below), while the generic assertions work with any data type.

The macro parameters can be an lvalue or an rvalue because the parameters will be first assigned to local variables of the selected data type. Then, these local variables will be tested for whichever test that needs to be checked.

Assigning the macro parameter to a local variable can be useful. These local variables will be of type dtype and if the parameters don't match that type a warning will pop up.

Ever assertion is inside a block of do { } while (0).

Printed Messages

Whenever an assertion fails, a message will be printed to stderr. The message will look something like this:

Assertion Failed at FILE:FUNCTION:LINE for { ACTUAL }: DETAILS

The first information is the file where that assertion failed. Then the function name and the line number. Then in place of ACTUAL, a stringified version of the actual parameter, which is the variable being checked in the assertion, will be printed.

In DETAILS is where more information about the assertion will be printed. This is the most useful part of these macros. In here, the actual value of the variable will be printed along with the expected value or range or lower bound, etc. In here you will be able to debug your application to check the expected value(s) against the actual one.

Example

#include "utl/assert.h"

void is_one_hundred(int variable)
{
    cmc_assert_equals(int32_t, 100, variable);
}

int main(void)
{
    int my_var = 9;
    is_one_hundred(my_var);
}

This will print the following message:

Assertion Failed at main.c:is_one_hundred:5 for { variable }: Expected: 100 Actual: 9

cmc_assert_state

This is a global variable that can be used to test if all assertions passed. If any assertion fails, this variable will be set to false. If an assertion passes this variable will not be set back to true. If you wish to, you can set the state back to true manually.

static bool cmc_assert_state = true;

This variable is used in test.h utility to automatically pass or fail a unit test. Once the unit test finishes, this variable is set back to true so that another unit test may follow.

dtype

These are the data types supported by the Valued Assertion macros:

• int8_t
• int16_t
• int32_t
• int64_t
• uint8_t
• uint16_t
• uint32_t
• uint64_t
• intmax_t
• uintmax_t
• size_t
• float
• double

The following two are only accepted by cmc_assert_equals and cmc_assert_not_equals:

• ptr
• bool

Note that ptr is used for any pointers. They are first casted to void * and then their address is compared.

Note that bool will be expanded to _Bool.

Overview

Single Value Assertion Macros

• cmc_assert - Asserts that an expression evaluates to true;
• cmc_assert_equals - Asserts that a value from type dtype equals another;
• cmc_assert_not_equals - Asserts that value from type dtype does not equals another;
• cmc_assert_greater - Asserts that a value from type dtype is greater than a lower bound;
• cmc_assert_greater_equals - Asserts that a value from type dtpype is greater than or equal to a lower bound;
• cmc_assert_lesser - Asserts that a value from type dtpype is lesser than an upper bound;
• cmc_assert_lesser_equals - Asserts that a value from type dtpype is lesser than or equal to an upper bound;
• cmc_assert_in_range - Asserts that a value from type dtpype is within a certain range;
• cmc_assert_not_in_range - Asserts that a value from type dtpype is outside of a certain range.

Array Assertion Macros

• cmc_assert_array_equals_any - Assert that two arrays are equal element by element;
• cmc_assert_array_within_any - Assert that each element in the array are within a bounds;
• cmc_assert_array_outside_any - Assert that each element in the array are out of bounds;
• cmc_assert_array_sorted_any - Assert that the array is sorted.

Valued Assertion Macros

Contents

• cmc_assert
• cmc_assert_equals
• cmc_assert_not_equals
• cmc_assert_greater
• cmc_assert_greater_equals
• cmc_assert_lesser
• cmc_assert_lesser_equals
• cmc_assert_in_range
• cmc_assert_not_in_range

cmc_assert

Asserts that an expression evaluates to true.

#define cmc_assert(expression)

Parameters

• expression - An expression that needs to be evaluated to true.

cmc_assert_equals

Asserts that a value equals another expected value.

#define cmc_assert_equals(dtype, expected, actual)

Parameters

• dtype - One of the possible data types listed here
• expected - The expected value for this assertion
• actual - A variant that is checked against the expected value

cmc_assert_not_equals

Asserts that a value does not equal another.

#define cmc_assert_not_equals(dtype, not_expected, actual)

Parameters

• dtype - One of the possible data types listed here
• not_expected - The value that is not expected for this assertion
• actual - A variant that is checked against the not expected value

cmc_assert_greater

Asserts that a value is above a certain lower boundary.

#define cmc_assert_greater(dtype, boundary, actual)

• dtype - One of the possible data types listed here
• boundary - The expected lowest possible value (excluded)
• actual - A variant that is checked against the boundary value

cmc_assert_greater_equals

Asserts that a value is above a certain lower boundary or equal to it.

#define cmc_assert_greater_equals(dtype, boundary, actual)

• dtype - One of the possible data types listed here
• boundary - The expected lowest possible value (included)
• actual - A variant that is checked against the boundary value

cmc_assert_lesser

Asserts that a value is below a certain upper boundary.

#define cmc_assert_lesser(dtype, boundary, actual)

• dtype - One of the possible data types listed here
• boundary - The expected highest possible value (excluded)
• actual - A variant that is checked against the boundary value

cmc_assert_lesser_equals

Asserts that a value is below a certain upper boundary or equal to it.

#define cmc_assert_lesser_equals(dtype, boundary, actual)

• dtype - One of the possible data types listed here
• boundary - The expected highest possible value (excluded)
• actual - A variant that is checked against the boundary value

cmc_assert_in_range

Asserts that a value is within a certain range. Range is inclusive on both ends.

#define cmc_assert_in_range(dtype, lower_bound, upper_bound, actual)

• dtype - One of the possible data types listed here
• lower_bound - Smallest value of the expected range
• upper_bound - Highest value of the expected range
• actual - A variant that is checked against lower and upper boundaries value

cmc_assert_not_in_range

Asserts that a value is not within a certain range. Range is inclusive on both ends.

#define cmc_assert_not_in_range(dtype, lower_bound, upper_bound, actual)

• dtype - One of the possible data types listed here
• lower_bound - Smallest value of the not expected range
• upper_bound - Highest value of the not expected range
• actual - A variant that is checked against lower and upper boundaries value

Generic Assertion Macros

Contents

• cmc_assert_array_equals_any
• cmc_assert_array_within_any
• cmc_assert_array_outside_any
• cmc_assert_array_sorted_any

cmc_assert_array_equals_any

Assert that two arrays are equal element by element. from_index and to_index are both inclusive.

#define cmc_assert_array_equals_any(dtype, array1, array2, comparator, \
                                    from_index, to_index)

• dtype - The type of the array. Can be of any data type.
• array1 - First array to be compared
• array2 - Second array to be compared
• comparator - A comparator function pointer that has two dtype arguments and returns -1 if the first is less then the second, 0 if both are equal or 1 if the first is greater then the second
• from_index - First index from both arrays to compare (inclusive)
• to_index - Last index from both arrays to compare (inclusive)

cmc_assert_array_within_any

Assert that each element in the array are within a certain boundary. Both ends are inclusive.

#define cmc_assert_array_within_any(dtype, array, comparator, lower_bound, \
                                    upper_bound, from_index, to_index)

• dtype - The type of the array. Can be of any data type
• array - Array to be checked if its elements are within a given range
• comparator - A comparator function pointer that has two dtype arguments and returns -1 if the first is less then the second, 0 if both are equal or 1 if the first is greater then the second
• lower_bound - Smallest value of the given range
• upper_bound - Highest value of the given range
• from_index - First index from the array to compare (inclusive)
• to_index - Last index from the array to compare (inclusive)

cmc_assert_array_outside_any

Assert that each element in the array are outside of a certain boundary. Both ends are inclusive.

#define cmc_assert_array_outside_any(dtype, array, comparator, lower_bound, \
                                     upper_bound, from_index, to_index)

• dtype - The type of the array. Can be of any data type
• array - Array to be checked if its elements are within a given range
• comparator - A comparator function pointer that has two dtype arguments and returns -1 if the first is less then the second, 0 if both are equal or 1 if the first is greater then the second
• lower_bound - Smallest value of the given range
• upper_bound - Highest value of the given range
• from_index - First index from the array to compare (inclusive)
• to_index - Last index from the array to compare (inclusive)

cmc_assert_array_sorted_any

Asserts that an array is sorted.

#define cmc_assert_array_sorted_any(dtype, array, comparator, from_index, \
                                    to_index)

• dtype - The type of the array. Can be of any data type
• array - Array to be checked if it is sorted
• comparator - A comparator function pointer that has two dtype arguments and returns -1 if the first is less then the second, 0 if both are equal or 1 if the first is greater then the second
• from_index - First index from the array to compare (inclusive)
• to_index - Last index from the array to compare (inclusive)

foreach.h

For-Each macros. Since doing a for loop with iterators can be a lot to write, these macros solve that problem. There are two of them:

• CMC_FOREACH - Goes from the beginning of a Collection to the end
• CMC_FOREAC_REV - Goes from the end of a Collection to the beginning

CMC_FOREACH

#define CMC_FOREACH(PFX, SNAME, ITERNAME, TARGET)

• PFX - Functions prefix
• SNAME - Struct name
• ITERNAME - Iterator variable name
• TARGET - Target collection variable name

CMC_FOREACH_REV

#define CMC_FOREACH_REV(PFX, SNAME, ITERNAME, TARGET)

• PFX - Functions prefix
• SNAME - Struct name
• ITERNAME - Iterator variable name
• TARGET - Target collection variable name

Example

#include "cmc/list.h"
#include "utl/foreach.h"

CMC_GENERATE_LIST(i32l, i32list, int32_t)

int main(void)
{
    struct i32list *list = i32l_new(100, &(struct i32list_fval) { NULL });

    for (int i = 0; i < 100; i++)
        i32l_push_back(list, i);

    CMC_FOREACH(i32l, i32list, it, list)
    {
        int value = i32l_iter_value(&it);
        size_t index = i32l_iter_index(&it);

        if (index == 0)
            printf("[ %d, ", value);
        else if (index == i32l_count(list) - 1)
            printf("%d ]\n", value);
        else
            printf("%d, ", value);
    }

    i32l_free(list);
}

futils.h

Contains common functions that can be used by Functions Table, instead of writing another one every time.

A quick list of functions present in this file:

log.h

Simple and customizable logging macros. Messages can have a custom logging level and a custom file output. This customization can be done via the global variable cmc_log_config. Logs are outputted to stderr.

cmc_log_type

Defines the possible Log Levels. These are used to categorize log messages. The higher the number, the more severe or important that message is. Check out here

enum cmc_log_type
{
    CMC_LOG_TRACE = 1,
    CMC_LOG_DEBUG = 2,
    CMC_LOG_INFO  = 3,
    CMC_LOG_WARN  = 4,
    CMC_LOG_ERROR = 5,
    CMC_LOG_FATAL = 6
};

CMC_LOG_COLOR

If this macro is defined, logging will be outputted with ANSI color escape codes. If you are logging into a file, these escape codes are not printed.

Log Functions

cmc_log_trace

Defines a message with a Log Level of CMC_LOG_TRACE.

#define cmc_log_trace(fmt, ...)

• fmt - A string that contains a text to be written that may contain format specifiers
• ... - Optional. Values to be formatted into the string that will be printed

cmc_log_debug

Defines a message with a Log Level of CMC_LOG_DEBUG.

#define cmc_log_debug(fmt, ...)

• fmt - A string that contains a text to be written that may contain format specifiers
• ... - Optional. Values to be formatted into the string that will be printed

cmc_log_info

Defines a message with a Log Level of CMC_LOG_INFO.

#define cmc_log_info(fmt, ...)

• fmt - A string that contains a text to be written that may contain format specifiers
• ... - Optional. Values to be formatted into the string that will be printed

cmc_log_warn

Defines a message with a Log Level of CMC_LOG_WARN.

#define cmc_log_warn(fmt, ...)

• fmt - A string that contains a text to be written that may contain format specifiers
• ... - Optional. Values to be formatted into the string that will be printed

cmc_log_error

Defines a message with a Log Level of CMC_LOG_ERROR.

#define cmc_log_error(fmt, ...)

• fmt - A string that contains a text to be written that may contain format specifiers
• ... - Optional. Values to be formatted into the string that will be printed

cmc_log_fatal

Defines a message with a Log Level of CMC_LOG_FATAL.

#define cmc_log_fatal(fmt, ...)

• fmt - A string that contains a text to be written that may contain format specifiers
• ... - Optional. Values to be formatted into the string that will be printed

Configuration

cmc_log_config

This is an anonymous static struct that can be directly modified to change logging levels, enable or disable output or change file output.

static struct
{
    enum cmc_log_type tlevel;
    enum cmc_log_type flevel;
    bool              tenabled;
    bool              fenabled;
    bool              enabled;
    FILE *            file;
} cmc_log_config = { 0, 0, true, true, true, NULL };

Members

• tlevel - Terminal log level (stderr)
• flevel - File log level
• tenabled - Terminal logging enabled if true
• fenabled - File logging enabled if true
• enabled - Enables or disables all logs
• FILE *file - File for output

This configuration is global to every log. The FILE pointer is not handled by the API and needs to be able to write to the file.

Log Level

By tuning tlevel and flevel (both accessed from cmc_log_config) you can filter which log messages are printed or not.

• If the log level is 0, all logs are enabled
• If the log level X is positive:
  • All levels less than X will be disabled
  • If X is greater than the level of FATAL, all logs are disabled
• If the log level X is negative:
  • All levels greater than abs(X) are enabled
  • If abs(X) is greater than the level of FATAL, all logs are enabled

Examples

If you want to output only TRACE logs to a file and the rest to stderr:

• cmc_log_config.tlevel = CMC_LOG_DEBUG
• cmc_log_config.flevel = -CMC_LOG_TRACE

If you want to output only FATAL to stderr and the rest to a file:

• cmc_log_config.tlevel = CMC_LOG_FATAL
• cmc_log_config.flevel = -CMC_LOG_ERROR

If you want to output only FATAL and ERROR to a file an nothing to stderr:

• cmc_log_config.tlevel = CMC_LOG_FATAL + 1
• cmc_log_config.flevel = CMC_LOG_ERROR

Summary

• Log Level > 0: "Allow all log levels that are greater than this, including it"
• Log Level < 0: "Allow all log levels that are smaller than this, including it"

Meanings

What does each Log Level means? It depends on the application. In here you will read more about how the C Macro Collections library uses each of these Log Levels, but this does not mean you should use them like described.

• TRACE - Trace is used to describe the inner workings of a function or an algorithm. These messages can be used extensively, meaning that their content is probably not very useful, even for debugging.
• DEBUG - Mainly used for debugging, tracking certain variables, checking if pointers were deallocated or anything useful to help visualizing what your program is doing in general.
• INFO - Info can be used as a heads up. Something that is important to note, but is not quite a warning or an error.
• WARN - Warnings are attributed to all cases where the function can recover from and usually treated by it. In most cases the user can treat these warnings himself.
• ERROR - Something really bad happened. Your program will not crash yet but depending on what comes next, it will. This might be attributed to pointers that shouldn't be null because later functions might use it.
• FATAL - This will probably be the last logging message before your program crashes or goes into madness. Fatal errors are commonly attributed to dereferencing NULL pointers.

test.h

A simple Unit Test utility used by the C Macro Collections Library. It has two main components: a Unit and a Test.

This utility uses two other libraries defined in the C Macro Collections library:

• assert.h
• timer.h

When a test is created inside a unit, it will first set the global variable cmc_assert_state to true. Then, inside the test you can use the assertions provided by the assert.h library to pass or fail a unit test automatically. By the end of a test the variable will be checked. If false it means that a certain assertion failed.

The runtime of each Unit Test is calculated using the timer.h library.

CMC_CREATE_UNIT

Creates a Unit that can contain tests.

#define CMC_CREATE_UNIT(UNAME, VERBOSE, BODY)

• UNAME - Unit name. This needs to be a valid function name!
• VERBOSE - Either true or false. If true, prints every message of PASSED or FAILED from each test
• BODY - A block of code containing tests

CMC_CREATE_TEST

Creates a test within a unit. This macro can only be used inside the BODY of a CMC_CREATE_UNIT since it uses local variables allocated by the latter.

#define CMC_CREATE_TEST(TNAME, BODY)

• TNAME - Test name
• BODY - A block of code containing the test itself

Inside a test you can use the assertions from assert.h to automatically pass or fail a test.

CMC_TEST_ABORT

Aborts a unit test. This will jump to a goto located at the end of the Unit Test. Must be called inside a CMC_CREATE_TEST.

#define CMC_TEST_ABORT()

cmc_test_info

Contains information about a Unit Test. Used internally.

struct cmc_test_info
{
    uintmax_t total;
    uintmax_t passed;
    uintmax_t failed;
    uintmax_t assert_total;
    uintmax_t assert_failed;
    bool aborted;
    bool verbose;
};

• uintmax_t total - Total tests in the unit test
• uintmax_t passed - Total tests passed in the unit test
• uintmax_t failed - Total tests failed in the unit test
• uintmax_t assert_total - Total assertions in the unit test
• uintmax_t assert_failed - Total assertions failed in the unit test
• bool aborted - If the unit test was aborted
• bool verbose - Information about each test is displayed

CMC_TEST_COLOR

Define this macro if you wish to have color output from the messages printed by each test. Note that a Unit Test need to have VERBOSE equal to true.

Example

#include "utl/test.h"

CMC_CREATE_UNIT(check_math, true, {
    CMC_CREATE_TEST(summation, {
        // assert.h already comes with test.h
        cmc_assert_equals(int32_t, 4, 2 + 2);
    });

    CMC_CREATE_TEST(subtraction, {
        cmc_assert_equals(int32_t, -1, 2 - 3);
    });

    CMC_CREATE_TEST(this will fail, {
        // test names can be text as long as they don't have a comma
        cmc_assert_greater(double, 1.0, 0.0);
    });

    CMC_CREATE_TEST(fish, {
        // You can also manually fail a test
        if (strcmp("2 + 2", "fish") != 0)
            cmc_assert_state = false;
    });

    CMC_CREATE_TEST(abort!, {
        if (4 % 2 == 0)
            CMC_TEST_ABORT();
    });

    CMC_CREATE_TEST(sad..., {
        // This test won't be called because unit test was aborted above
        cmc_assert(true);
    });
});

int main(void)
{
    // returns how many tests failed
    return check_math();
}

timer.h

A very simple library that encapsulates clock() from <time.h>, making life easier.

cmc_timer

struct cmc_timer
{
    clock_t start;
    clock_t stop;
    double result;
};

• clock_t start - Start of timing
• clock_t stop - End of timing
• double result - Result in milliseconds

cmc_timer_start

Starts the timer by setting start with clock().

#define cmc_timer_start(timer)

• timer - A struct cmc_timer variable

cmc_timer_stop

Sets the stop variable with clock() and calculates the result in milliseconds.

#define cmc_timer_start(timer)

• timer - A struct cmc_timer variable

Example

#include <stdio.h>

#include "utl/timer.h"

int main(void)
{
    struct cmc_timer t;

    cmc_timer_start(t);

    size_t total = 0;

    for (size_t i = 0; i < 1000000000; i++)
        total += i;

    cmc_timer_stop(t);

    printf("Sum took %.0lf milliseconds to calculate\n", t.result);
}

Minimal Example

(TODO this example is currently outdated)

Lets create a list of type int, add some elements to it and get the sum of all the elements printed on the screen.

Include headers

#include <cmc/list.h>

First you need to include only the necessary headers. It is not recommended that you include everything with macro_collections.h, only in cases where you might be using almost all features from the library.

Generating a list

// CMC_GENERATE_LIST(PFX, SNAME, V)
CMC_GENERATE_LIST(il, int_list, int)

The List is also known as vector, ArrayList and dynamic array. In fact the latter is the best description for this collection. It is a dynamic array that can grow and shrink as needed. To generate it we can simply call the macro CMC_GENERATE_LIST after our includes. It has three parameters:

Initializing and adding elements

// Allocate an int_list with an initial capacity of 100
int_list *list = il_new(100);

// Adding elements to the back of the list
for (int i = 0; i <= 1000; i++)
{
    if (!il_push_back(list, i))
    {
        // Something went wrong (check out documentation)
    }
}

To initialize any collection we call a function _new. Since the PFX parameter is set to il all functions related to our list of integer will be prefixed by il, so _new becomes il_new.

The list name is int_list as defined by SNAME. This type is a typedef like:

typedef struct SNAME##_s SNAME;

Which expands to:

typedef struct int_list_s int_list

To add elements to the back of a list we can use il_push_back. This function will first check if the list has enough space for a new element. If not, reallocate the internal buffer with doubled size and then add the new element.

Iteration

It is recommended that the iterator is allocated on the stack

// Resulting sum will be stored here
int sum = 0;

// Declare our iterator (allocating it on the stack)
int_list_iter it;

// Loop for each element
for (il_iter_init(&it, list); !il_iter_end(&it); il_iter_next(&it))
{
    // Accessing the value
    int elem = il_iter_value(&it);

    sum += elem;
}

printf("%d\n", sum);

There are 6 (2 optional) steps to iterate over the elements of any collection:

Note that all iterator functions are prefixed by the user defined prefix and then by iter (il + iter = il_iter). Also, the steps 1 and 6 are optional so il_iter_new and il_iter_free are not used in the example.

By the end of the example we have the variable sum with the sum of all integers inside our list. We can then print it and this example is almost done.

Freeing resources

// void il_free(int_list *_list_, void(*deallocator)(int))
il_free(list, NULL);

The list is currently allocated in memory. To deallocate it we call il_free. This function takes a pointer to the allocated list and a pointer to a deallocator function that will be responsible for deallocating each element in the list. This last parameter is optional and we won't be using it since our data type int is not allocated in the heap. This optional parameter can be set to NULL to be ignored by the il_free function.

Compile and run

source.c

#include <cmc/list.h>

CMC_GENERATE_LIST(il, int_list, int)

int main(void)
{
    int_list *list = il_new(100);

    for (int i = 0; i <= 1000; i++)
    {
        if (!il_push_back(list, i))
        {
            // Something went wrong (check out documentation)
        }
    }

    int sum = 0;

    int_list_iter it;

    for (il_iter_init(&it, list); !il_iter_end(&it); il_iter_next(&it))
    {
        int elem = il_iter_value(&it);
        sum += elem;
    }

    printf("%d\n", sum);

    il_free(list, NULL);
}

If the source file is source.c, all you have to do is to include the src folder to the include path and compile. The following example uses gcc:

gcc source.c -I path/to/library/src

Conclusion

The C Macro Collections Library is prepared to accept any data type and is highly customizable. It is also very easy to integrate and no previous compilation is required. The library also comes with many utilities in the utl folder that are designed to work well with all collections.