Inconsistent document about autocasting

Crystal Contrib
1

reading Type autocasting - Crystal

class Foo
  @x : Int64 = 10 # OK, 10 fits in an Int64

  def set_x(y)
    @x = y
  end
end

Foo.new.set_x 1 # Error: "at line 5: instance variable '@x' of Foo must be Int64, not Int32"

but the program runs just fine now, does anything changes between versions?

2

Hello @femto, I think is related to this discussion:

And this PR that changed the autocasting behavior.

Hope that helps.
Cheers.

3

It works if you type the setter parameter. E.g. def set_x(y : Int64).

4

Hello, it works even without type the setter parameter.
what I mean is it runs just fine,
but the docs says it should report an error.

5

Ah okay, then yea the linked PR seemed to have changed that. Documentation probably needs updated to reflect it. Mind filing an issue on the crystal-book repo?

2 Likes
6

This probably a new introduced bug?

I always set env like this:

 ╰─ $ echo $CRYSTAL_OPTS 
-Dstrict_multi_assign -Dno_number_autocast

It should no number autocast, why not raise error on 1.11.0 ?

7

If not mistaken the new feature is behind a different flag: -Dno_restrictions_augmenter

Cheers.

8

This should deff be added to Compile-time flags - Crystal then.

1 Like
9

How confusing it is! to introduce such a new compile time flag.

What is the obvious difference of above issue with this ?

10

I know why this compile time flag named no_restrictions_augmenter after read Experimental: restriction augmenter by asterite · Pull Request #12103 · crystal-lang/crystal · GitHub

Anyway, i consider this flag (by default, enabled currently) probably cause some run-time error.

class Foo
  @x : Int32 = 10 # OK, 10 fits in an Int64

  def set_x(y)
    @x = y
  end
end

Foo.new.set_x Int32::MAX + 1

Unhandled exception: Arithmetic overflow (OverflowError)
from 1.cr:9:26 in ‘__crystal_main’
from /home/zw963/Crystal/share/crystal/src/crystal/main.cr:129:5 in ‘main_user_code’
from /home/zw963/Crystal/share/crystal/src/crystal/main.cr:115:7 in ‘main’
from /home/zw963/Crystal/share/crystal/src/crystal/main.cr:141:3 in ‘main’
from /usr/lib/libc.so.6 in ‘??’
from /usr/lib/libc.so.6 in ‘__libc_start_main’
from /home/zw963/.cache/crystal/crystal-run-1.tmp in ‘_start’
from ???

I created a issue for fix document about this.