Functional C

An experimental library to make functional programming in C simple. Note that at this time only integers are supported. There is need for generic functions, though. So feel free to contribute.

Building and Installing

$ make && make install

OS X Installation

$ brew install https://raw.github.com/leroux/homebrew-formulae/master/libfc.rb

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List Format

A list is stored in an array xs with its elemental length (+1, for keeping the length) at index 0, xs[0]. The list's data is kept in the array xs ranging from xs[1] and so on. For example, the list [50, 23, 41, 21] would be kept in the following fashion - [5, 50, 23, 41, 21]. Taking into account that index 0 is reserved for the array's total length, the list's elemental length is (5 - 1) or simply 4.

Function Type Definitions

// Unary function.
typedef int (*ufunc)(int a);

// Binary function.
typedef int (*bfunc)(int a, int b);

// Predicate. Unary function that returns a boolean.
typedef bool (*pred)(int a);

Transformations

// Applies an unary function f to each element of a list xs.
int *map(ufunc f, int *xs)

// Filters a list xs by a predicate p.
int *filter(pred p, int *xs);

// Folds/Reduces list xs by a binary function *f* applied to
// accumulator value and each element of a list xs starting from the left.
int foldl(bfunc f, int accumulator, int *xs);

List Operations

// Prints out a list xs in a readable format, i.e. `[1, 4, 3]`.
void list_print(int *xs);

// Returns the first element of a list. Very trivial.
int head(int *xs);

// Returns the tail (the list w/o the head).
int *tail(int *xs);

// Sum of a list xs.
int sum(int *xs);

// Product of a list xs.
int product(int *xs);

Numerical Operations

// Add numbers a, b.
int add(int a, int b);

// Subtract a number b from a number a.
int sub(int, a, int b);

// Multiply a number a with a number b.
int mul(int a, int b);