Brainfuck - The language
Brainfuck is an esoteric programming language created by Urban
Müller to be extremely minimalistic. It features only 8 commands
but despite this is a Turing complete programming language.
Whilst it is technically possible to write a program to solve a
large series of problems, in practicality it is very difficult to
write anything more than a toy. Frankly there has been a small
wave of people implementing interpreters and compilers for the
language and very few people writing anything substantial. Wilfred
Hughes has an interesting article about this.
I shall, as always, endeavour to be part of the problem!
Memory
Brain fuck operates on a simple memory model which has a consecutive
series of cells that can store 8 bit numbers.This series of cells
is usually known as a tape as a nod to early computing machines
which used physical rolls of tape for memory. A pointer starts at
the beginning of the tape and moves around according to the program
instructions. The data at each cell location can be incremented or
decremented.
Usual implementations
have 30,000 cells in the tape. There are a series of edge cases that
can be handled slightly differently depending on the implementation.
These include: integer overflow, integer underflow, buffer overflow,
buffer underflow. These can be handled by wrapping data or pointers
back around to the beginning, infinitely expanding buffers or just
crashing the program. The sensible choice depends on the features
used by a given program to do computations.
Loops
Loops have the ability to do two things at once: they act as a
means to repeat instructions, and they act as conditional checks.
In brainfuck the open loop operator will go to the next instruction
if the value at the current data cell is not zero, otherwise the
execution jumps to the loop end.
