This channel is intended for people just starting with the Raku Programming Language (raku.org). Logs are available at irclogs.raku.org/raku-beginner/live.html
Set by lizmat on 8 June 2022.
08:07 dakkar joined 10:14 habere-et-disper joined 10:16 frost joined
habere-et-disper How do you subset a Pair ? 10:26
I tried:
m: subset File-Rank of Pair where (Str => Int); my File-Rank $foo = 'd' => 4;
camelia Type check failed in assignment to $foo; expected File-Rank but got Pair (:d(4))
in block <unit> at <tmp> line 1
Nemokosch two things 10:28
to answer the question: you can probably write a check utilizing .key and .value 10:29
where { .key ~~ Str && .value ~~ Int }
second: keep in mind that a Pair is not meant to be used as a tuple. The two elements have a hierarchic relation, moreover the key cannot have a container while the value can 10:30
the key is really meant to identify the value. Just to make sure you know what you are going for. 10:31
10:32 frost left
habere-et-disper Thanks Nemokosch. I had wanted something more succinct like the documentation gives for other types, eg: `subset Foo of List where (Int,Str);` but I guess not. 10:33
Thank you for the tuple distinction. Awareness created. :D 10:36
Nemokosch The lack of proof is not the proof of lack so there could be something like that still 😛 10:39
that's mostly a matter of smartmatching, though, so one would need to check Pair.ACCEPTS 10:40
According to Rakudo sources, a $pair1 ~~ $pair2 if and only if $pair1.key ~~ $pair2.key && $pair1.value ~~ $pair2.value... which tells me that it could work 10:45
oh, gotcha... 10:47
dd Str => Int
m: dd Str => Int
Raku eval :Str(Int)
Nemokosch this still doesn't give it away but hold on
m: dd (Str => Int).key 10:48
Raku eval "Str"
Nemokosch there
it is not the type but simply the string Str, that's why another string doesn't smartmatch to it
lemme join quickly, the IRC bot is more up-to-date 10:50
10:50 Nemokosch joined
Nemokosch m: subset File-Rank of Pair where ((Str) => Int); my File-Rank $foo = 'd' => 4; say $foo; 10:51
camelia d => 4
Nemokosch dang!
m: subset File-Rank of Pair where ((Str) => Int); my File-Rank $foo = 21 => 4; say $foo;
camelia Type check failed in assignment to $foo; expected File-Rank but got Pair (21 => 4)
in block <unit> at <tmp> line 1
Nemokosch m: subset File-Rank of Pair where ((Str) => Int); my File-Rank $foo = 4 => 'd'; say $foo;
camelia Type check failed in assignment to $foo; expected File-Rank but got Pair (4 => "d")
in block <unit> at <tmp> line 1
Nemokosch habere-et-disper: TLDR, ((Str) => Int) works; the key needs to be disambiguated from unquoted strings 10:52
10:52 Nemokosch left
lizmat m: subset File-Rank of Pair where Pair.new(Str,Int); my File-Rank $foo = 4 => 'd'; say $foo; 11:05
camelia Type check failed in assignment to $foo; expected File-Rank but got Pair (4 => "d")
in block <unit> at <tmp> line 1
lizmat m: subset File-Rank of Pair where (Pair.new(Str,Int)); my File-Rank $foo = 4 => 'd'; say $foo;
camelia Type check failed in assignment to $foo; expected File-Rank but got Pair (4 => "d")
in block <unit> at <tmp> line 1
lizmat weird
habere-et-disper LOL. Thanks for all this ! I see the chess board alternatives as : 11:15
`subset File-Rank of Pair where ( ('a'..'h') => 1..8 );`
or better as a tuple and with far less parentheses:
`subset File-Rank of List where 'a'..'h', 1..8;`
13:04 habere-et-disper left 13:29 jgaz joined
Anton Antonov I have a variable that has a grammar name, say, $grName . I want make a new grammar that inherits from $grName and uses its TOP rule. How do I do that? 13:40
I tried grammar New is ::($grammarName) {...} but I am getting the message: "Cannot stringify object of type QAST::Var". 13:41
lizmat is $grammarName set at compile time? 13:42
Anton Antonov Hm... yes. I have a statement like my $grName = "R322"; . Then I use EVALFILE($*CWD ~ "/resources/$grName.raku");. 13:44
Maybe I should use an actual grammar object in the inheritance specification? But, then again, how do I do that? Here is the grammar object: my $gr = EVAL $grCode. 13:46
lizmat how would you do it if they were ordinary classes ? 13:47
Anton Antonov @lizmat It is a good question -- I do not know. 13:52
I can use another call to EVAL to construct the new class or grammar. (Simple.) 13:59
moritz isn't there like a add_parent_class meta method? 14:00
Anton Antonov @moritz I looked into the meta programming documentation pages. Without finding something relevant, but I did not look that hard... 14:01
moritz there's an `add_parent` method in src/Perl6/Metamodel/MultipleInheritance.nqp 14:03
the meta model is sadly very under-documented
Anton Antonov Cool! 14:04
14:11 tea3po left 14:12 tea3po joined, tea3po left 14:13 ab5tract joined, tea3po joined
Nemokosch On one hand it is sad, on the other hand, if it's not Raku and its stability is not guaranteed, maybe documenting too much of it would also be pointless 14:16
14:36 Heptite joined 14:52 deoac joined
moritz you can make it Raku by documenting it and writing tests for it 15:08
gfldex moritz: it's a bit more involved, see: gfldex.wordpress.com/2023/02/15/yes-but-dont/ 16:16
Nemokosch And the title is perfectly fitting 16:34
Yes, you can, and please don't. There is already more than enough Rakudo in Raku 16:35
16:37 jgaz left 16:39 dakkar left
moritz gfldex: I don't see how the code from your post and documenting metamodel methods relate 17:00
ah, you actually meant the part where you you have to compose the class again 17:01
17:13 ab5tract left 17:58 jgaz joined 18:15 jgaz left 18:30 deoac left 19:27 ab5tract joined 19:54 ab5tract left 21:20 orylesor joined
orylesor Hi. Call me Teresa. (she/her) 21:29
I'm an absolute beginner. Evaluated expressions in different programming languages, I understand basic programming concepts, I'm comfortable setting up programming languages and related tools, comfortable with the command line.
I'd just like to finally learn programming "proper" just for fun. I always had false starts. I absolutely love x86-64 assembly, I spent a few weeks with it. I could definitely keep going with it, I'm just concerned that I wouldn't learn programming "proper", whatever that means, since it's not even a programming language. I'm also very tempted to
get back to Raku (tried briefly before), I like the flexibility, I like "0.1 + 0.2 = 0.3", it's super cute.
I just can't make up my mind on what to do: Analysis paralysis. Sorry if this is totally off-topic, and that it's admittedly irrational. I just thought if I said my thoughts out loud, I might get unstuck.
Thanks.
falsifian Good luck finding your path, orylesor! 21:31
orylesor Thanks. <3
22:38 orylesor left
Anton Antonov @orylessor Consideb trying out, “just using” Raku packages you like. Scan raku.land… 23:40
I.e. raku.land .

Powered by Cro and the Raku® Programming Language.

Please report any issues / comments / feature requests as an issue on App::Raku::Log.

Thank you!