C Extensions

lil provides two operators that give you direct access to memory. These only work when compiling with lil -c. Running them with the interpreter produces an error.

If you’ve used Python’s ctypes module to get the address of a C object or read memory at a raw pointer, the concept is the same: @ is like ctypes.addressof() and ^ is like ctypes.string_at().

Address-of (@)

The @ operator returns the memory address of a variable as a number:

x = 42
addr = @x
write(addr)

The address will be different every time you run the program (ASLR). One run might print 140732789041152, the next 140732789041184.

You can also get addresses of string variables:

msg = "hello"
msg_addr = @msg
write(msg_addr)

Dereference (^)

The ^ operator reads a value from a memory address:

x = 42
addr = @x
value = ^addr
write(value)    : prints 42

This round-trips through a pointer: write a value, take its address, then dereference it back.

Practical Example

x = 42
x_addr = @x
x_val = ^x_addr
write("address: ", x_addr)
write("value: ", x_val)

Each run will show a different address but always the same value.

Safety Warning

Dereferencing an invalid address will crash your program with a segfault, just like Python’s ctypes.string_at(bad_address):

value = ^9999999    : almost certainly a segfault

These operators are useful for low-level programming and interfacing with hardware at specific memory addresses (MMIO). Use them carefully.

In the interpreter (lil file.lil), both operators produce an error.