Enum (cont) space returns false even if it contains a space

[Kaiepi]

The Problem

See title.

Expected Behavior

enum ∋ ' ' should return True.

Actual Behavior

It returns False.

Steps to Reproduce

enum Foo «' '»;
say Foo.enums ∋ ' ';

Environment

• Operating system:
  OpenBSD bastille.kennel.qt 6.4 GENERIC.MP#364 amd64
• Compiler version (perl6 -v):
  This is Rakudo version 2018.12-158-gf39be10ce built on MoarVM version 2018.12-13-g473324ee3
  implementing Perl 6.d.

[lizmat]

This problem is not just for homemade enums or special enums like with a space. It's for all enums with a False value:

dd Endian.enums; # Map.new((:BigEndian(2),:LittleEndian(1),:NativeEndian(0)))
say Endian.enums (cont) NativeEndian;  # False

enum Foo (a => "foo", b => "");
dd Foo.enums;  # Map.new((:a("foo"),:b("")))
say Foo.enums (cont) "a";  # True
say Foo.enums (cont) "b";  # False

[lizmat]

Actually, this has nothing to do with enums:

my %h = a => 0, b => 1;
say "a" (elem) %h;   # False
say "b" (elem) %h;   # True

[lizmat]

And from there: this is actually not a bug, but a result of Set semantics: elem and friends apply them to their parameters. So if you say:

say Endian.enums (cont) NativeEndian;  # False

You are actually saying:

say Endian.enums.Set (cont) NativeEndian;  # False

Which makes sense if you see:

dd Endian.enums.Set; # Set.new("LittleEndian","BigEndian")

So maybe we need to document this gotcha.

[lizmat]

An alternate way to check if something is in an enum, is to use :exists:

enum Foo <a b c>;
say Foo.enums<a>;          # 0
say Foo.enums<a>:exists;   # True

[lizmat]

Trap documented with Raku/doc@ca3067e5e7 , closing now