Created
October 1, 2011 23:18
-
-
Save puffnfresh/1256794 to your computer and use it in GitHub Desktop.
Example of structural typing and tagged unions (variants)
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| data Option a = Some a | None | |
| let addOne o = match o | |
| case (Some x) = x.value + 1 | |
| case None = 1 | |
| // addOne's type is: | |
| // Option {value: Number} | |
| // These compile: | |
| console.log (addOne (Some { | |
| value: 100 | |
| })) | |
| console.log (addOne None) | |
| // These don't: | |
| // console.log (addOne (Some { | |
| // blah: 0 | |
| // })) | |
| // console.log (addOne (Some { | |
| // value: "asdf" | |
| // })) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment