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Comment by le0n | Hacker News Reader

Haskell/GHC will soon have an extension for linear types, which will bring the languages much closer: http://blog.tweag.io/posts/2017-03-13-linear-types.html

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Yeah right. If only the standard library (the base package) could immediately be converted to use linear types and we can all benefit from that! (Hint: it won't. Even the fairly no-brainer AMP and BBP took an absurdly long time. This is extremely slow by Rust standards. The Haskell community might, but the stewards of the standard libraries don't have the move-fast-and-break-things attitude.)

> Even the fairly no-brainer AMP and BBP took an absurdly long time

This is because, believe it or not, Haskell is actually used in the real world and people care about their code not becoming broken.

Did rust ever have a large scale breaking change? Anyway, the linear type proposal is designed to be completely backwards compatible so that shouldn't be as big of an issue.

> Did rust ever have a large scale breaking change?

Pre 1.0: every day

Post 1.0: not really, though I guess it depends on your definition of "large scale"; we've made some soundness fixes, but made sure that they were warnings for a long time first, so most people experienced no breakage.

Yes I know it's completely backwards compatible. But in practice if the standard libraries don't change, (a) there won't be a ready source of inspiration and examples to copy from; (b) actually the feature is really geared more towards libraries than applications, so it's less useful if the base library doesn't adopt it wholeheartedly.

Fair enough, although it would be easy to have an alternative prelude with linear types that libraries could depend on. Just that the extra dependency would really suck.

Haven't sunk a lot of time into it yet to be honest, I think the biggest beneficiaries will be streaming libraries and non-gced data structures like long lived queues?

Rust uses affine types instead of linear types per some statements I've seen on the subject. I wonder why they wouldn't use affine types in this. Either way, it's good they're adding it.

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