| oshaboy | Yknow I like Raku but I wish there was a way to say "actually I don't want the string to be Unicode normalized" | 00:07 | |
| nemokosch | out of curiosity, what is your use case? | 00:19 | |
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| Voldenet | re > stackoverflow.com/questions/516441...9#79892319 | 02:42 | |
| I don't overly hate idea, but it makes code really verbose | 02:43 | ||
| I've tried that a few times and overall Result<T, Error> needs good syntax support | 02:45 | ||
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| Voldenet | but I suppose something like this would be pretty neat: | 02:47 | |
| Hm, nevermind, I thought about using .resume with value but it ended up being really convoluted | 02:48 | ||
| overall probably there's no need to complicate this | 02:55 | ||
| m: sub some-fail { die "random" }; sub x { CATCH { default { return 42; } }; return some-fail() }; say x() | |||
| camelia | 42 | ||
| nemokosch | well I don't like this more but for sure it does less | 02:56 | |
| the truth is, I can entertain the task but in general I think it's massive code smell if you are ever going to need to do something like this | 02:57 | ||
| providing separate defaults for separate unusual code paths | |||
| Voldenet | it totally isn't – having default value if something is not responding right is sane | 02:58 | |
| nemokosch | that is sane - having different defaults on different kind of problems is insane | ||
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| Voldenet | actually I've used that and it's not horrible | 02:59 | |
| nemokosch | I'm not sold for sure | ||
| Voldenet | # sub do-request { CATCH { when DeserializationException { return http-error(400) }; when ConnectionError { return http-error(500); }}; return http-json(200, do-request()); } | 03:01 | |
| that might have some typos but you have the idea | |||
| ofc it's also possible to do that…: | |||
| # sub do-request { CATCH { when handle-error($_) { $_.http-format }; }; return http-json(200, do-request()); } | 03:02 | ||
| nemokosch | it's almost like this is a good reason to not use exceptions but failures at the very least | ||
| Voldenet | Failures don't have stack trace though | 03:03 | |
| it's hardly ever a good idea to not have stack | |||
| or rather - error has to be very local | |||
| nemokosch | well, you either want to use something as a value, or troubleshoot it, but not both at once | ||
| here, it seems that you want to use it as a value and you don't need a stack trace - you don't even need custom control flow | 03:04 | ||
| just a special value | |||
| Voldenet | but then do-request doesn't have to bother with understanding all the errors | ||
| it just does regular golden path with "die" when necessary | 03:05 | ||
| nemokosch | I don't understand | ||
| Voldenet | > my $db = db-connect; LEAVE $db.try-disconnect; return $db.get-item($request.int-from-post<id>) | 03:06 | |
| that'd be code of some method | 03:07 | ||
| and all of these methods can throw 10 exceptions | |||
| socket connection, dns resolution, timeouts, wrong request | |||
| or rather, deserialization error | 03:08 | ||
| when writing that you don't want to handle errors on-site because request would be failed anyway… but you don't want to hardwire the code to return HTTP codes | |||
| nemokosch | none of those seem to be recoverable | ||
| I still don't see this middle ground where by default you'd still want to propagate but cherry-pick some to return values | 03:09 | ||
| Voldenet | Well, connection error and friends should be 500 - server error | 03:10 | |
| nemokosch | also, at this point I can't see the big win | ||
| Voldenet | but deserialization error would be 400 | ||
| failure to find item would be 404 | |||
| nemokosch | in my solution, you still have the exceptions, it's just the "catching" is the default behavior | ||
| Voldenet | however it's only responsibility of http, not the internal method that gets the item | ||
| nemokosch | and the "rethrowing" is the manual part | ||
| also, you avoid the sub wrapping and the phaser | 03:11 | ||
| to my understanding, my version also doesn't need manual propagation on all levels of the call stack, only one rethrow - specifically needed because some exceptions were handled on that level | 03:13 | ||
| not just handled but "recast" as values | |||
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| Voldenet | well, you can't handle one specific error and not others | 03:16 | |
| nemokosch | how not? | ||
| Voldenet | m: class X is Exception { }; my $result = do given try { die X.new }, $! { when *, X::AdHoc { "Some other exception thrown: $_[1]" }; default { "Proper value: $_[0]"; } }; say $result | ||
| camelia | Use of Nil in string context Proper value: in block at <tmp> line 1 |
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| nemokosch | okay, this is hard to read | 03:17 | |
| but if I get the idea: this can be addressed by one line of code | |||
| and it's a constant one line | |||
| Voldenet | + you get to choose which errors are handled and which should be thrown further | 03:19 | |
| for completness | 03:20 | ||
| m: class X is Exception { }; my $result = sub n() { CATCH { when X::AdHoc { return "bar" }; }; die "blah"; }(); say $result | |||
| camelia | bar | ||
| Voldenet | m: class X is Exception { }; my $result = sub n() { CATCH { when X::AdHoc { return "bar" }; }; X.new.throw }(); say $result | ||
| camelia | Died with X in sub n at <tmp> line 1 in block <unit> at <tmp> line 1 |
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| nemokosch | well, you get to choose that either way, don't you | 03:21 | |
| this is not a difference | |||