Moduledhall-1.42.3Haskell2010

Dhall.Lint

This module contains the implementation of the dhall lint command

7 values

Packagedhall-1.42.3
Exports7
LanguageHaskell2010
LicenceBSD-3-Clause
SourceLint.hs

Lint

7 declarations

valuelint :: Eq s => Expr s Import -> Expr s Import

Automatically improve a Dhall expression

Currently this:

removes unused let bindings with removeUnusedBindings.
fixes let a = x ≡ y to be let a = assert : x ≡ y
consolidates nested let bindings to use a multiple-let binding with removeLetInLet
fixes paths of the form ./../foo to ../foo

valueremoveUnusedBindings :: Eq a => Expr s a -> Maybe (Expr s a)

Remove unused Let bindings.

valuefixAssert :: Expr s a -> Maybe (Expr s a)

Fix Let bindings that the user probably meant to be asserts

valuefixParentPath :: Expr s Import -> Maybe (Expr s Import)

This transforms ./../foo into ../foo

valueaddPreludeExtensions :: Expr s Import -> Maybe (Expr s Import)

This transforms https://prelude.dhall-lang.org/…/foo to https://prelude.dhall-lang.org/…/foo.dhall

valueremoveLetInLet :: Expr s a -> Maybe (Expr s a)

The difference between

let x = 1 let y = 2 in x + y

and

let x = 1 in let y = 2 in x + y

is that in the second expression, the inner Let is wrapped by a Note.

We remove such a Note in order to consolidate nested let-blocks into a single one.

valueuseToMap :: Expr s a -> Maybe (Expr s a)

This replaces a record of key-value pairs with the equivalent use of toMap

This is currently not used by dhall lint because this would sort Map keys, which is not necessarily a behavior-preserving change, but is still made available as a convenient rewrite rule. For example, {json,yaml}-to-dhall use this rewrite to simplify their output.