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This project is an optmizing Lisp compiler and bytecode VM.
It can compile to JavaScript, or compile to bytecode and execute in a VM.
Bytecode VM:
./program --vm --debug < fib10.lisp
0: push_closure ["n"]
-> 0: load_var n
-> 1: push_const 2.0
-> 2: less_than
-> 3: jump 6 // go to 6
-> 4: load_var n
-> 5: jump 17 // exit
-> 6: load_var n
-> 7: push_const 1.0
-> 8: sub 2
-> 9: load_var fib
-> 10: call_lambda 1
-> 11: load_var n
-> 12: push_const 2.0
-> 13: sub 2
-> 14: load_var fib
-> 15: call_lambda 1
-> 16: add 2
1: store_var fib
2: push_const 10.0
3: load_var fib
4: call_lambda 1
5: load_var print
6: call_lambda 1
55
Compile to JavaScript:
./program --js < fib10.lisp
/* lisp-to-js */
let print = console.log;
(() => {
let fib = ((n) => n < 2 ? n : ( fib (( n -1), )+ fib (( n -2), ))
)
; print ( fib (10, ), )
})()
The implemented optimizations are constant folding and propagation, and dead code elimination:
; before optimization
(let ((b 2) (c 3))
(print
(+
(+ b 4 c)
(- b c 7)
)))
; after optimization
(let () (print 1))The Lisp variant is very similar to Little Lisp.
; atoms
1 ; f64 numbers
a ; symbols
; arithmetic expressions
(+ 1 2) ; 3
(- 1 2) ; -1
; control flow expressions
(< 1 2) ; true
(> 1 2) ; false
(if (< 1 2) (+ 10 10) (+ 10 5)) ; 20
; lambda expressions
(lambda (x) (+ x x)) ; function that doubles
; variable definition
(let ((a 1)) (print a)) ; prints 1
(let ((double (lambda (x) (+ x x)))) (double 2)) ; 4Required (one of):
--jsoutput JavaScript to stdout--vmcompile to bytecode and execute in VM
Optional:
--optimizefor optimization--debugshow annotated bytecode
cargo test