Overloaded record fields for GHC - Well-Typed - The Haskell Consultants

TL;DR: GHC HEAD (but not GHC 7.8) will soon support OverloadedRecordFields, an extension to permit datatypes to reuse field labels and even turn them into lenses. IntroductionThe Haskell records system is a frequent source of frustration to Haskell programmers working on large projects. On the face of it, it is simple: a datatype such as data Person = Person { id :: Int, name :: String } gives ris

[ruicc]

(r { name :: t }) => といったfieldNameのConstraint, 既存の型制約(type-level string使っているが)に脱糖されるらしい

[tanakh]

(´･_･`)