Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/luizperes/small-lisp
Small Lisp REPL written in Haskell
https://github.com/luizperes/small-lisp
Last synced: 2 months ago
JSON representation
Small Lisp REPL written in Haskell
- Host: GitHub
- URL: https://github.com/luizperes/small-lisp
- Owner: luizperes
- License: gpl-3.0
- Created: 2018-04-16T06:55:34.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2019-04-23T18:14:57.000Z (over 5 years ago)
- Last Synced: 2024-08-10T11:03:00.976Z (5 months ago)
- Language: Haskell
- Size: 21.5 KB
- Stars: 6
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# small-lisp
> A Small Lisp REPL fully written in Haskell (It is possible to run mostly anything in this interpreter, but some bugs are yet to be fixed).
### Documentation
You can find the EBNF and much more on __Small Lisp__ [here](http://www.cs.sfu.ca/~cameron/Teaching/384/chap2.ps).
### How to get started
Simply run: `ghc sl.hs interpreter.hs parser.hs tokenizer.hs unparser.hs`
#### Running
`./sl `
##### Example
`./sl test/third.sl`
###### REPL will start
```Haskell
REPL> { x = plus[2; 3] : times[4; x] }
20
```
_// Obs.: The REPL will not work if you do not pass at least one file as param._
### Hello World
###### hello.sl
```Haskell
hello-world[x] = cons[x; (hello world)]
```
```Haskell
./sl hello.sl
REPL> hello-world["luiz"]
(luiz hello world)
```
### Brainfuck Interpreter
_// Please not that the BF interpreter is incomplete_
###### bf.sl
```Haskell
;;;
;;; Brainfuck
;;;
;;; Util functions
append[list1; list2] =
[endp[list1] --> list2;
otherwise --> cons[first[list1]; append[rest[list1]; list2]]]
length[list] =
[ endp[list] --> 0
; otherwise --> plus[length[rest[list]]; 1] ]
element-at[idx; tape; accTape] =
[ endp[tape] --> error["NoElementError"]
; otherwise --> {
tail = [ endp[rest[tape]] --> (); otherwise --> rest[tape] ] :
[ eqp[length[accTape]; idx] --> first[tape]
; otherwise --> element-at[idx; tail; append[accTape; cons[head;()]]] ]
}]
setv-element-at[v; idx; tape; accTape] =
[ endp[tape] --> accTape
; otherwise --> {
tail = [ endp[rest[tape]] --> (); otherwise --> rest[tape] ] :
[ eqp[length[accTape]; idx] --> setv-element-at[v; idx; tail; append[accTape; cons[v;()]]]
; otherwise --> setv-element-at[v; idx; tail; append[accTape; cons[first[tape];()]]] ]
}]
add-value[v; idx; tape] =
setv-element-at[plus[element-at[idx; tape; ()]; v]; idx; tape; ()]
;;; Brainfuck related functions
reset-tape[x; tape] =
[ lessp[x; 0] --> tape
; otherwise --> reset-tape[minus[x; 1]; cons[0; tape]]]
inc[idx; tape] = add-value[1; idx; tape]
dec[idx; tape] = add-value[-1; idx; tape]
inc-ptr[idx] = plus[1; idx]
dec-ptr[idx] = minus[idx; 1]
exec[accCode; realCode; idx; tape; stack] =
[ endp[accCode] --> tape
; otherwise --> {
head = first[accCode];
tail = [ endp[rest[accCode]] --> (); otherwise --> rest[accCode] ] :
[ eq[+; head] --> exec[tail; realCode; idx; inc[idx; tape]; stack]
; eq[-; head] --> exec[tail; realCode; idx; dec[idx; tape]; stack]
; eq[>; head] --> exec[tail; realCode; inc-ptr[idx]; tape; stack]
; eq[<; head] --> exec[tail; realCode; dec-ptr[idx]; tape; stack]
; eq[?; head] --> exec[tail; realCode; dec-ptr[idx]; tape; stack]
; eq[|; head] --> exec[tail; realCode; dec-ptr[idx]; tape; stack] ]
}]
bf[code; tape-size] = {
arrCode = explode[code] :
exec[arrCode; arrCode; 0; reset-tape[tape-size; ()]; ()]
}
```