BLisp

BLisp is a statically typed Lisp like programming language which adopts effect system for no_std environments. BLisp supports higher order RPC like higher order functions of functional programming languages.

This repository provides only a library crate. Please see blisp-repl to use BLisp, and baremetalisp which is a toy OS.

Homepage is here.

Features

• Algebraic data type
• Generics
• Hindley–Milner based type inference
• Effect system to separate side effects from pure functions
• Big integer
• Supporting no_std environments

How to Use

use blisp;

fn main() {
    let code = "(export factorial (n) (Pure (-> (Int) Int))
    (if (<= n 0)
        1
        (* n (factorial (- n 1)))))";
    let exprs = blisp::init(code).unwrap();
    let ctx = blisp::typing(&exprs).unwrap();

    let e = "(factorial 10)";
    blisp::eval(e, &ctx).unwrap();
}

If Rust compiler or linker says warning of fmod, please add fmod manually as follows.

#[no_mangle]
extern "C" fn fmod(x: f64, y: f64) -> f64 {
    libm::fmod(x, y)
}

Cargo.toml

[dependencies.blisp]
version = "0.3"

Examples

"Hello, World!" ; "Hello, World!"
(+ 0x10 0x20)   ; 48
(+ 0b111 0b101) ; 12
(+ 0o777 0o444) ; 803
(car '(1 2 3))  ; (Some 1)
(cdr '(1 2 3))  ; '(2 3)
(map (lambda (x) (* x 2)) '(8 9 10)) ; '(16 18 20)
(fold + 0 '(1 2 3 4 5 6 7 8 9))      ; 45
(reverse '(1 2 3 4 5 6 7 8 9))       ; '(9 8 7 6 5 4 3 2 1)
(filter (lambda (x) (= (% x 2) 0)) '(1 2 3 4 5 6 7 8 9)) ; '(2 4 6 8)

Version History

0.3.9

• fix a bug on the garbage collector

0.3.8

• fix a bug on typing
  • check the number of arguments
  • (+ 10) was passed typing rule
• add != and neq
  • (!= 10 10)
  • (neq (Some "Hello") 10)

0.3.7

• add bit shift operators
  • (<< 8 4) ; shift left
  • (>> 128 4) ; shift right
• add Char type
• add character literal
  • `H`
• add chars and str functions
  • chars converts String to (List Char)
    • (chars "Hello, World!")
  • str converts (List Char) to String
    • (str '(`H` `e` `l` `l` `o`))

0.3.6

• make <, >, <=, >= functions' type (Pure (-> (t t) Bool))
  • perform comparison between 2 values whose types are same
  • (< "Hello" "World")
  • (>= (Some 5) (Some 19))
• add lt, gt, leq, geq functions
  • perform comparison between any 2 values
  • function type is (Pure (-> (t1 t2) Bool))
  • (eq "Hello" 10)
  • (lt (Some 6) "Hello")

0.3.5

• add string type and literal
  • String
  • "Hello World!"
• make equal function generics
  • it can be used for non-integer types
  • (= "Hello" "Hello")
  • (= (Some 1) (Some 2))
• fix a bug on typing
  • (= (Some 1) (Some 2)) could not be typed properly

0.3.4

• fix bugs on typing
  • bug 1: some locally defined functions are cannot be called
  • bug 2: empty list cannot be typed properly
• add filter and reverse functions to prelude

0.3.3

• add hexadecimal, octal, and binary
  • 0xabcDEF
  • 0o777
  • 0b1010

0.3.2

• add pow to compute exponent
  • example: (pow 10 20)
  • type of pow: (Pure (-> (Int Int) (Option Int)))
  • if the exponent portion is greater or equal to 2^32, then return None
• add sqrt
  • example: (sqrt 16)
  • type of sqrt: (Pure (-> (Int) (Option Int)))
  • if the value is less than 0, then return None
• add bitwise operations
  • band, bor, bxor

0.3.1

• garbage collection is ready (mark and sweep)