I wrote a lisp interpreter in a couple hours based off the excellent risp essay.

Sadly, I don't know rust well enough to do the 50:50 rule -- I already don't know how to make a programming language! So here it is in TS.

pnpm install; pnpx ts-node src/main.ts

All numbers are JS numbers and wrote as 1.

Literals use quoted syntax -- 'zkldi' is the literal string zkldi.

Symbols are unquoted -- foo refers to the variable zkldi.

everything else is your standard lisp affairs.

• (+ 1 2)
• (- 1 2)
• (def 'name' value)
• (echo expr) - a no-op, since all expressions actually do this anyway.
• (env) - prints the global scope

I got bored of implementing functions after this, but I should probably look into the whole lambda stuff.

(+ 1 2)
-> FLOAT 3

(def 'age' (+ 9 9))
-> FLOAT 18

(def 'name' 'zkldi')
-> LITERAL 'zkldi'

(def name 'cool!')
-> LITERAL 'cool!'

(echo 'zkldi')
-> LITERAL 'cool!'