haskell-servant/servant

Generic records causes very slow compile times

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#1,038 opened on Sep 18, 2018

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Description

apparently, large APIs using the Servant.API.Generic record mechanism are orders of magnitude slower to compile than their :<|> equivalent

https://twitter.com/mattoflambda/status/1041622124576661504

I'm not sure how much we can do about this, but we could at least benchmark, create a minimal example that triggers this behaviour, and submit it to GHC as a bug

Contributor guide

Research direction
Create a minimal example that reproduces the slow compile times with Servant.Generic records, benchmark it, and submit the findings to GHC as a bug report.
Tech stack
haskell
Domain
backendapi
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
HaskellServant
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30