Brim

Brim is an optimizing brain* interpreter than nonetheless strives to be very easy and pleasant to use.

Features

Details

Brim uses a wrapping 30000-cell tape, with a single wrapping signed byte in each cell.

Debug

If compiled in debug mode, or with the feature flag debug, brim will recognize the character ;, and will dump several relevant bits of info (the tape, the tape pointer, and three instructions for context) to output.

File I/O

With the -i | --input and -o | --output flags, brim can read/write to/from files instead of stdin/stdout.

Regardless of source or destination, all I/O is buffered to provide a fast and reliable experience (the output is flushed on each newline, and upon exit).

Optimizations

Brim internally uses a token-based intermediary structure to execute the code. First, it groups together add, subtract, left, and right instructions to save needless cycles.

Then, it performs several macro-optimizations to reduce common operations to a single "instruction". Currently, it recognizes:

• Zeroing a cell ([-])
• Setting a cell to a value ([-]++++)
• Soon, moving one cell to another ([->+<] / [>+<-])

The token-based structure makes these trivial to recognize, since repeating instructions have already been collapsed into one.

Finally, it iterates over each bracket ([/]) and pre-loads its destination token, so executing them requires zero lookup time (it just overrides the IP).

These are all run in a buffered I/O environment, as detailed above.

Roadmap

Brim isn't finished yet! My hopes for the future include:

• More macro-optimizations
• Heavy micro-optimization of brim itself
• More variations (non-wrapping, signed, varying tape size)