List Comprehension++

ID:2958912
 
Jan 1, 3:34 pm
Applies to:DM Language
Status: Open
Issue hasn't been assigned a status value.
The ability to "inline" the for() procedure.

mob/Login()
    var list/old_list = list(1,2,3,4,5,6,7,8,9)
    var list/new_list = [number for number in old_list if number % 2 == 0]
Jan 3, 2:52 pm
this would be incredibly jank

-1
Jan 4, 3:22 am
I don't know what a good syntax to match dm would be, but it would be a nice feature imo since we can't define procedures for /list.

I wouldn't say it's jank just advanced comprehension.
Jan 6, 2:19 pm (Edited on Jan 7, 7:53 am)
I can see how this is an ask but I don't think it's a good value trade. Pythonisms tend to be a bit of a flow break for me, although perhaps that's just because I don't do a lot of work in python. I think I can happily accuse python list comprehension of being clever first, maintainable second.

var/list/old_list = list(1, 2, 3, 4, 5, 6, 7, 8, 9)
var/list/new_list = list()
for (var/number in old_list)
  if (number % 2 == 0)
    new_list += number


As a possibly syntax, [A[ as B] in C[ if D]]. I don't believe I'm being unrealistic in decoupling the hint of A from B, or in making B and D optional.

var/list/mob_friends = [friend as /mob in faction.friends]
var/list/jelly_friends = [mob/friend in faction.friends if friend.jelly > 0]


Sure! Cute. Or if we make it slightly realistic ...

var/list/jelly_friends = [mob/playable/opossum/friend as /mob/playable/opossum in faction.friends if friend.IsActivePlayer() && friend.NotPlayingDead() && friend.MeetsJellyNeeds()]


If we want to do more than trivial numerics, line ends start heading right fast. To me that's just an even less comprehensible pyramid of doom.

-1
Jan 6, 2:34 pm
For this use-case, it would be nice to see something like JavaScript's map()/reduce()/filter() implemented for the /list prototype.
Jan 6, 3:50 pm
Yeah, I could see that.

var/list/outlist = list_map(inlist, /proc/some_transformer)

/proc/some_transformer(entry, index)
return ...
Jan 6, 9:16 pm
 
var list/list = list(1,2,3,4,5,6,7,8,9)
list = [for item in list % 2 == 0 ? item : continue]


Eh? Ehh?