Type-checked non-empty strings

Type-checked non-empty strings(exploring-better-ways.bellroy.com)

34 points by surprisetalk 3 days ago | 11 comments

muglug 1 hour ago |

Very cool that the language allows specification of a type in this way.

I added a similar type — “non-empty-string” to a typechecker for PHP, and it’s been adopted widely in the PHP ecosystem. It turns out to be pretty handy, especially when there’s a full type system to support it.

IshKebab 2 hours ago |

"Huh never heard of Bellroy... I wonder what they're using Haskell for..."

Turns out it's some kind of bags and accessories brand!

ambicapter 5 minutes ago | |

I once saw a job ad for a company selling a horoscope app that required Haskell. An unusual conjunction for sure.

flexagoon 1 hour ago | |

I've had a Bellroy bag, they're not the most fashionable but super high quality and well thought-out. Just like Haskell code—maybe that's why they like it.

qbane 2 hours ago | |

I pondered for a while, it IS the company I used to know

ivanjermakov 2 hours ago |

Language is not mentioned in a title, so my first thought was about TypeScript type wizardry. Turns out it's as simple as `Exclude<string, "">`.

https://www.typescriptlang.org/docs/handbook/utility-types.h...

Edit: nevermind, LLM fooled me.

antipurist 2 hours ago | |

It's simple, and it doesn't work as `Exclude` only applies to union types. For type `string` it just returns the same type `string`.

phpnode 1 hour ago | | |

yup, it's not possible to do it safely with a simple unparameterised type: https://www.typescriptlang.org/play/?#code/C4TwDgpgBAcg9gOwK...

ralferoo 2 hours ago | |

It is very much mentioned in the article title and the first sentence. It's just HN that's truncated the title.

Cthulhu_ 1 hour ago | |

Speaking of TS, there's stuff in there for typing strings / string formats: https://www.typescriptlang.org/docs/handbook/2/template-lite...

nvme0n1p1 1 hour ago | |

Daily reminder that TypeScript's type checker is not sound.

https://www.typescriptlang.org/play/?#code/C4TwDgpgBAcg9gOwK...