Hacker News Reader

Comment by zoffix222 | Hacker News Reader

They don't need to be "missing". my \working-days = 200; Creates a working-days variable that you can't change.

Isn't that sort of a mis-feature that we don't expect to see in code very much? I thought mainly people would be using sigils, and ideally the correct sort of sigil to indicate if it is a single thing, list of things, hash of things, callable thing, etc.

I wouldn't call it a misfeature. I think especially in math stuff it would be useful. I've used Δ in my math for Color module and it both has the natural mathematical meaning and must not change after I calculate it: https://github.com/zoffixznet/perl6-Color/blob/master/lib/Co...

What is a mis-feature is you can't assign-create to these variables when they're part with sigil-bearing variables, so, for example, here I ended up using a sigiled-Δ, which isn't as pretty :) https://github.com/zoffixznet/perl6-Color/blob/master/lib/Co...

Aiui it's for any time a coder prefers that a noun's name does not emphasize/convey the basic nature of the thing the noun refers to.

Fwiw you can assign to such "raw" nouns if you declare that the raw noun you're declaring refers in turn to a rw container. For example, a plain `$` is a container (an anonymous Scalar):

  my \Δ = my $ = 100;
  Δ = 200;

I came up with the following idiom when pondering snippets on twitter and the fundamental problem that twitter treats strings of the form `@foo` as twitter handles which messes up the formatting of tweets containing `@` sigil'd nouns:

  my \array =@= 1,2,3; array[2] = 200; say array;

displays

  [1 2 200]

I see it as a natural part of Perl 6's gradual typing approach, ie. a feature, not a mis-feature.

It can be mis-applied. It arguably has been mis-applied in this example. But I can also argue it the other way. It depends on whether the intro's goal is to address overly simplistic general criticisms ("sigils are ugly and unnecessary!") or to inculcate mature understanding from the get go.

Reply on news.ycombinator.com