Crate blc

blc is an implementation of the binary lambda calculus in Rust.

Binary lambda calculus basics

Binary lambda calculus (BLC) is a minimal, purely functional programming language based on a binary encoding of the untyped lambda calculus with De Bruijn indices.

Lambda terms have the following representation in BLC:

term	lambda	BLC
abstraction	λM	00M
application	MN	01MN
variable	i	1i0

Since BLC programs are basically lambda calculus terms, they can be applied to other terms. In order to be applicable to binary (but not BLC-encoded) input, it has to be lambda-encoded first. Bytestrings are lambda-encoded as Church lists of bytes and bytes are lambda-encoded as Church lists of lambda-encoded bits.

Bits 0 and 1 are lambda-encoded as Church booleans:

bit	lambda	BLC
0	λλ2 (true)	0000110
1	λλ1 (false)	000010

Example: BLC-encoding steps for a byte representing the ASCII/UTF-8 encoded letter 'a':

encoding	representation
decimal	96
binary	01100001
lambda	λ1(λλ2)(λ1(λλ1)(λ1(λλ1)(λ1(λλ2)(λ1(λλ2)(λ1(λλ2)(λ1(λλ2)(λ1(λλ1)(λλ1))))))))
BLC (hex)	16 16 c 2c 10 b0 42 c1 85 83 b 6 16 c 2c 10 41 0

Reexports

pub use self::execution::run;

pub use self::encoding::binary::to_bits;

pub use self::encoding::binary::from_bits;

Modules

encoding	BLC-relevant encodings
execution	Binary lambda calculus execution