rtpg on Lisp implementation in sed

Comment on Lisp implementation in sed parent

this is more of a "symbols per line" argument rather than "symbols in the language" argument.

    grade = (student) ->
      if student.excellentWork
        "A+"
      else if student.okayStuff
        if student.triedHard then "B" else "B-"
      else
        "C"

(from coffescript examples)

Imagine how many more symbols that would have in any lisp dialect

lispm 12y

    (defun grade (student)
      (cond ((excellent-work student) :a+)
            ((okay-stuff     student) (if (tried-hard student) :b :b-))
            (t                        :c)))

illo 12y

Erlang, just for fun:

  grade(#student{work=Work, tried_hard=Tried}) -> grade1(Work, Tried).
  grade1(excellent_work, _) -> 'a+';
  grade1(okay_stuff, yes) -> b;
  grade1(okay_stuff, _) -> 'b-';
  grade1(_, _) -> c.

Edit: formatting.

JadeNB 12y

Or, if we're going to go with Prolog-inspired syntax, then why not Prolog?

    grade(Student, Grade) :-
        worked(Student, Work), work_grade(Work, Student, Grade).
    work_grade('Excellent', _, 'A+').
    work_grade('Okay', Student, 'B') :- tried_hard(Student).
    work_grade('Okay', _, 'B-').
    work_grade(_, _, 'C').

I'm a bit rusty, and I don't have a Prolog interpreter to hand to test, so I might have got some syntax wrong.

sfk 12y

I'm always amazed that I hardly ever program in Lisp and yet these short snippets are more readable than any other language.

dghf 12y

Yes, I've never understood why

    dostuff(x)

is considered so much more readable than

    (dostuff x)

bad_login 12y

   ;; comparing with racket:

   (define (grade student)
     (cond 
      [(excellent-work student) "A+"]
      [(and (okay-stuff student) (tried-hard student)) "B"]
      [(okay-stuff student) "B-"]
      [else "C"]))

   ;; Or

   (require racket/match)

   (define (grade student)
     (match (map (lambda (fn) (fn student)) 
                 '(excellent-work okay-stuff tried-hard))
       [(list #t _ _)  "A+"]
       [(list _ #t #t) "B"]
       [(list _ #t _)  "B-"]
       [else           "C"]))

dghf 12y

Clojure:

    (defn grade [student]
      (cond
        (excellent-work student)  "A+"
        (okay-stuff student)      (if (tried-hard student) "B" "B-")
        :else                     "C"))

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