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Comment by tjalfi | Hacker News Reader

Set-based programming is a fairly old idea. Jack Schwartz[0] created SETL[1] in 1969.

SETL2[2] and SETLX[3] interpreters are available.

Here is a sample program[4] by Keith S. Thompson. I have removed the comment header for brevity.

  program Fizz_Buzz;
    fizz := {3, 6..100};
    buzz := {5, 10..100};
    fizzbuzz := fizz * buzz;
    fizz -:= fizzbuzz;
    buzz -:= fizzbuzz;
    num := {1..100} - fizz - buzz - fizzbuzz;
    line_map := {[n, "Fizz"]     : n in fizz} +
                {[n, "Buzz"]     : n in buzz} +
                {[n, "FizzBuzz"] : n in fizzbuzz} +
                {[n, n]          : n in num};
    loop for i in [1..100] do
        print(line_map(i));
    end loop;
  end Fizz_Buzz;

[0] http://www.settheory.com

[1] http://wiki.c2.com/?SetlLanguage

[2] http://www.setl.org/setl/

[3] https://randoom.org/Software/SetlX

[4] https://raw.githubusercontent.com/Keith-S-Thompson/fizzbuzz-...

Edited to fix formatting of footnotes and add newlines.

View on HN

That translates fairly well into Python, with its set type and list/set/dict comprehensions.

    def setrange(first, next, last):
        return set(range(first, last+1, next-first))
    
    fizz = setrange(3, 6, 100)
    buzz = setrange(5, 10, 100)
    fizzbuzz = fizz & buzz
    fizz -= fizzbuzz
    buzz -= fizzbuzz
    num = setrange(1, 2, 100) - fizz - buzz - fizzbuzz
    line_map = dict({n: "Fizz" for n in fizz}.items() +
        {n: "Buzz" for n in buzz}.items() +
        {n: "FizzBuzz" for n in fizzbuzz}.items() +
        {n: n for n in num}.items())
    for i in range(1, 100+1):
        print(line_map[i])

Some SETL features Python lacks:

• No ellipsis notation for ranges; must use the "range" function and add one to the maximum value, or define a custom "setrange" function

• Can't concatenate dictionaries; must concatenate their "items" lists and convert back to a dictionary

• No consistent map-lookup notation; collections are indexed with brackets, but functions are called with parentheses

You can concatenate dictionaries in Python:

a = {* * b, * * c}

(Python 3.5!)

Unless this is doing something unintended?

> No consistent map-lookup notation;

You can use .get() in Python on a dictionary :)

First time I learned about SETL at NYU was when I was learning about Spitbol.

Here is a fizzbuzz in Spitbol. Probably not the best way to do it.

      var a = 0;
      start
      +a = a + 1;
      break
      +lt(a,101) :f(end);
      x01
      +x = (remdr(a,3) + remdr(a,5)); eq(x,0) :s(x06);
      x02
      +y = remdr(a,3); eq(y,0) :s(x04);
      x03
      +z = remdr(a,5); eq(z,0) :s(x05)f(x07);
      x04
      +output = 'fizz' :(start);
      x05
      +output = 'buzz' :(start);
      x06
      +output = 'fizzbuzz' :(start);
      x07
      +output = a :(start);
      end

More: http://www.hakank.org/setl/fizzbuzz.setl

He also has pages on APL and k.

It was used in a 2000 era web app. Neat.

http://cs.nyu.edu/~bacon/phd-thesis/diss/node35.html

You're hired!

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