APIs

.malloc

C.malloc(size: num) -> ptr

Allocate memory block

Parameters (1)

size

Size of memory block, in bytes.

Return value

On success, a pointer to the memory block allocated by the function.

If size is zero or the function failed to allocate the requested block of memory, null is returned.

.calloc

C.calloc(count: num, size: num) -> ptr

Allocate and zero-initialize array

Parameters

count

Number of elements to allocate.

size

Size of each element.

Return value

Like C.malloc, but the returned memory block is zero-initialized.

.realloc

C.realloc(addr: ptr, size: num) -> ptr

Reallocate memory block

Parameters (2)

addr

Pointer to a memory block previously allocated with C.malloc, C.calloc or C.realloc.

If this is a null pointer, the function works like C.malloc.

size

• New size for the memory block, in bytes.

Return value

See C.malloc.

.free

C.free(addr: ptr)

Deallocate memory block

Parameters (1)

addr

A block of memory previously allocated by a call to C.malloc, C.calloc or C.realloc is deallocated, making it available again for further allocations.

Return value

None.

Must free pointers created by malloc, calloc and realloc to avoid memory leaks.

Do not free any pointer is freed or not formed by malloc, calloc and realloc.

.memcpy

C.memcpy(dest: ptr, src: ptr, size: num) -> ptr

Copy one buffer to another.

Parameters (2)

Return value

Return dest.

.memcmp

C.memcmp(a: ptr, b: ptr, count: num) -> num

Compares two buffers.

Parameters (2)

Return value

• Negative integer if a appears before b in lexicographical order.

• Zero if a and b compare equal, or count is zero.

• Positive integer if a appears after b in lexicographical order.

.memset

C.memset(dest: ptr, byte: num, count: num) -> ptr

Fill the memory block by the given byte.

Parameters (3)

dest

Pointer to the object to fill.

byte

Fill byte, an integer number in range 0 - 255.

count

Number of bytes to fill.

Return

Return dest.

.load

dll.load(path: str) -> ptr

Load a dynamic library (.dll, .so).

Parameters (1)

path

Path to file.

Return value

A handle in ptr of loaded library.

If path is invalid, return null.

.def

C.def(lib: ptr, name: str, ret: num, args: num[]) -> fn

Create a function that wraps C API function.

Parameters (4)

lib

Pointer of loaded library.

name

Name of exported function.

ret

C type of function return.

args

C type array of parameters.

Return value

If lib is null or invalid, return null.

If success, return a function.

Examples

Wrap abs function in msvcrt.dll

var crt = C.load('msvcrt.dll')
var abs = C.def(crt, 'abs', C.INT, [C.INT])
puts abs(-5)  // 5

.extern

C.extern(lib: ptr, sym: str) -> ptr

Get address of exported symbol in library.

Parameters (2)

lib

Pointer of loaded library.

sym

String of symbol.

Return value

Address pointer.

.sizeof

C.sizeof(type: num | ptr) -> num

C sizeof equivalent.

Parameters (1)

type

A struct created by C.struct or C type.

Return value

Size of given type, in bytes.

If the given type is invalid, return zero.

.cif

C.cif(callback: fn, ret: num, args: num[]) -> ptr

Create C API callback function from a given function.

Parameters (3)

callback

A function, except function created by C.def().

ret

C type of return.

args

C type array of parameters.

Return value

Pointer to a created callback function.

Examples

Win32 window procedure.

// Load user32
var user32 = C.load('user32.dll')

// LRESULT DefWindowProcA(HWND, UINT, WPARAM, LPARAM)
var DefWindowProc = C.def(
    user32, 'DefWindowProcA',
    C.PTR, [C.PTR, C.UINT, C.PTR, C.PTR]
)

// WNDPROC, like DefWindowProcA signature
var wndproc = C.cif(
    func(hwnd, msg, wparam, lparam) {
        // Process message
        return DefWindowProc(hwnd, msg, wparam, lparam)
    },
    C.PTR, [C.PTR, C.UINT, C.PTR, C.PTR]
)