How to translate this GorillaScript into LiveScript?

Question

I have this GorillaScript code to flatten arrays:

Array::compact  :=  #
  for filter value in this
     value and (typeof value.isempty != 'function' or not value.isempty()) and (typeof value != 'object' or Object.keys(value).length != 0)

GorillaScript is kinda dead. Could someone translate this into LiveScript for me please? I'm quite new to LiveScript.

score 1 · Accepted Answer · edited Mar 14 '17 at 11:51

1

A literal translation would look something like this.

Array.prototype.compact = ->
  [v for v in @ when v and (typeof v.isempty isnt \function or not v.isempty!) and (typeof v isnt \object or Object.keys value .length > 0)]

A more idiomatic example might be:

is-empty = ->
  | not it => false 
  | typeof it.isempty isnt \function or not it.isempty! => true
  | typeof it isnt \object or not Object.keys it .length > 0 => true
  | otherwise => it

Array.prototype.compact = -> [x for x in @ when not is-empty x]

Watch out, as this was done off the top of my head any my LiveScript's a bit rusty, but the general ideas here are ok.

edited Mar 14 '17 at 11:51

Ven

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answered Apr 03 '16 at 19:26

Dan Prince

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It's mostly right, although you're missing "=>" on the third line. But I'm getting the error "null is not an object (evaluating 'it.isempty')" when calling "[1, null, 2].compact()" – Sod Almighty Apr 03 '16 at 19:48
Perhaps add a case at the top " | not it? => false" ? – Sod Almighty Apr 03 '16 at 19:48
Yeah, as I said a bit rusty—what matters is the general concept. I guess your suggestion would be more semantically correct with respect to the original code, too. – Dan Prince Apr 04 '16 at 11:54
Thanks for the help. – Sod Almighty Apr 04 '16 at 14:52
renamed `empty?` to `is-empty`, since LS doesn't allow punctuation in identifiers :). – Ven Mar 14 '17 at 11:51

How to translate this GorillaScript into LiveScript?

1 Answers1