Tutorial II: Simple programs

This page is meant to get used to the language itself. I provide here various programs and functions, along with their python equivalents.

Hello, World!

(Python)

print("Hello, World!")

(Stacked)

'Hello, World!' out

Modular equivalence

Checks if a ≡ b (mod c).

(Python)

modequiv = lambda a, b, c: a % c == b % c

(Stacked)

{ a b c : (a b) c mod ... = } @:modequiv

This is a 3-arg function. It pairs a and b, implicitly maps with c mod, merges it to the stack with ..., then checks for equality with =.

Prime

Wilson's theorem: (Python)

import math
Wilson = lambda n: math.factorial(n - 1) % n == (n - 1) and n > 1

(Stacked)

{! n 1-! _1 n modequiv n 1 > and } @:wilson

This is an n-lambda that uses Wilson's theorem, that (n - 1)! ≡ -1 (mod n) ⇔ n is prime.

Trial division via recursion: (Python)

todo

(Stacked)

{ x :
  { e i :
    (e i) out
    [ 1 ]
    [
      [e i 1 + tdrec] [0] e i % 0 != ifelse
    ] i e sqrt > ifelse
  } @:tdrec
  [0] [x 2 tdrec] x 1 < ifelse
} @:tdprime