Intro
A bit of syntax for Lisp
The main idea is from: https://pschombe.wordpress.com/2006/04/16/lisp-without-parentheses/
plus the colon and the semicolon.
Check it out with Fish shell, guile Lisp interpreter and Python3:
guile -c (python3 parsing_scripts.py example1)
or:
rlwrap python3 comm.py -i echo | racket
rlwrap python3 comm.py -i echo | tee /dev/fd/2 | racket
# inside the "shell" input is multiline, ends with empty input line (hit ENTER twice)
FILE ls.syntax
ls /home ..
EXIT
-- second option shows what is actually passed to racket.
It uses Linux's (and Mac OSX' and FreeBSD's etc) /dev/fd/2 symlink to current stderr (also /dev/stderr).
Syntax
It's all work in progress. But overall the syntaxis consists of:
- the parentheses,
- meaningful indentation (a-la Python),
- the colon works like & in Haskel -- it nests a node in the current one,
- the semicolon means the end of "current node",
- (TODO) and the backslash \ should cancel the nesting of an indented line.
- for now comment is from
%till end of line - (TODO) and coma is like backwards colon/haskel-& -- nests the previous symbols in a node
The punctuation should work mostly in-line, indentation nests nodes accordingly.
Examples:
a : b c = (a (b c))
a : b : c ; d : r = (a (b (c))) (d (r))
a = (a (b c))
b c
a , b c = ((a) b c)
From the article
Condition:
(cond
((< x -1) (* x x))
((> x 1) (* x x))
((< x 0) (sqrt (abs x)))
(else (sqrt x)))
becomes
cond
(< x -1) (* x x)
(> x 1) (* x x)
(< x 0) (sqrt (abs x))
else (sqrt x)
or even
cond
(< x -1)
* x x
(> x 1)
* x x
(< x 0)
sqrt (abs x)
else
sqrt x
The let:
(let
((a (+ 1 v)) (b (car z)) (c (avg 8 3 w)) (d w))
(body-goes-here))
becomes
let
(a (+ 1 v)) (b (car z)) (c (avg 8 3 w)) (d w)
body-goes-here
or
let
a (+ 1 v)
b (car z)
c (avg 8 3 w)
d w
body-goes-here