Add Option to stdlib #158
Add Option to stdlib #158
Conversation
stdlib/option.gr
Outdated
| | (Some(a), Some(b)) => Some((a, b)) | ||
| | (Some(_), None) => None | ||
| | (None, Some(_)) => None | ||
| | (None, None) => None |
There was a problem hiding this comment.
| | (Some(a), Some(b)) => Some((a, b)) | |
| | (Some(_), None) => None | |
| | (None, Some(_)) => None | |
| | (None, None) => None | |
| | (Some(a), Some(b)) => Some((a, b)) | |
| | _ => None |
stdlib/option.gr
Outdated
| | (Some(a), Some(b)) => Some(fn(a, b)) | ||
| | (Some(_), None) => None | ||
| | (None, Some(_)) => None | ||
| | (None, None) => None |
There was a problem hiding this comment.
| | (Some(a), Some(b)) => Some(fn(a, b)) | |
| | (Some(_), None) => None | |
| | (None, Some(_)) => None | |
| | (None, None) => None | |
| | (Some(a), Some(b)) => Some(fn(a, b)) | |
| | _ => None |
stdlib/option.gr
Outdated
| | Some(Some(x)) => Some(x) | ||
| | Some(None) => None | ||
| | None => None |
There was a problem hiding this comment.
| | Some(Some(x)) => Some(x) | |
| | Some(None) => None | |
| | None => None | |
| | Some(Some(x)) => Some(x) | |
| | _ => None |
stdlib/option.gr
Outdated
| } | ||
| } | ||
|
|
||
| # TODO: Do you like `andThen` or should it be `flatMap` or both? |
There was a problem hiding this comment.
I would lean towards flatMap, since the "then" part of andThen feels like it could imply that something async is happening.
There was a problem hiding this comment.
+1. Plus, flatMap is nice since Options are monads/functors
stdlib/option.gr
Outdated
| } | ||
| } | ||
|
|
||
| # TODO: Would be cool to have a recursive version |
There was a problem hiding this comment.
I don't think the typechecker would let us write one without a custom type to match against :/
The type would have to look like this:
data RecOpt<a> = RecOptCons(Option<a>, RecOpt<a>) | RecOptNone
You could maybe get this to work with higher kinded types, but I'm not sure.
There was a problem hiding this comment.
Yeah, I'm not sure how calls to a recursive version would type-check in the first place...
|
@belph when I make your suggested changes, I get this warning:
How should I avoid that? |
|
I made the changes and rebased. We should figure out how to disable that warning for the stdlib maybe? |
|
Yeah, I'll make an issue. |
|
I wrote a thing to set the compiler's default warnings, and opened an issue so we can have them be configurable. (I made FragileMatch default to off, and left everything else as on for now.) |
This adds the
Optiondata type to pervasives, and additionally adds anoption.grmodule to the standard library that shamelessly reimplements APIs I've liked from OCaml, BuckleScript's Belt library, and Rust.I also added
peekbecause I think it is useful once there's currying and you can chain things with|>or similar.One glaring omission from this implementation is converting to/from Result because that doesn't exist yet.