spice stream
Hi, I'm learning Gleam by doing the exercises on https://exercism.org and I encountered this little issue:
fn foo(condition: Bool) -> String {
use <- condition |> bool.guard("OK")
"KO"
}
It says: Incorrect arity. Expected 3 arguments, got 2.
(This sample is a simplification of the real code)
white sonnet
That's right, you've not supplied all the arguments to bool.guard there
use doesn't have a special case where it behaves differently for pipe, so what you're doing doesn't work
spice stream
I thought it would be the same as use <- bool.guard(condition, "OK")
steep nexus
From the compiler POV that's extra work to figure out
bool.guard(condition, "OK") is a call expr
condition |> bool.guard("OK") is a pipeline expr
white sonnet
use always does either:
There is no special case for pipe and there never will be.
steep nexus
they're similar but not the same
spice stream
ok, I understand, thank you for your answers
pine trail
In general I'd avoid doing that because it's difficult to read, even if it worked
white sonnet
That's our motivation for not adding a special case there
spice stream
From the compiler POV that's extra work to figure out
From my (novice) POV bool.guard(condition, "OK") and condition |> bool.guard("OK") are both the same function (currying) asking one parameter
white sonnet
There's no technical limitation, it's a language design matter
daring stratus