Customizable elm-review rules for allowable pipeline styles.

elm, elm-review
elm-package install SiriusStarr/elm-review-pipeline-styles 1.3.1



Provides elm-review rules to forbid pipelines for code-style reasons.

Provided rules

For example, the usage of <| or the usage of excessively-long |> pipelines.

This rule works with the following pipeline types:

  • |> -- Right "pizza" pipelines, i.e. right function application, so-called because the operator resembles a slice of pizza 🍕.
  • <| -- Left "pizza" pipelines, i.e. left function application, so-called because the operator resembles a slice of pizza 🍕.
  • >> -- Right composition pipelines.
  • << -- Left composition pipelines.
  • foo (bar (baz (i (j k)))) -- Parenthetical application pipelines.

If you don't know where to start, be sure to check out ReviewPipelineStyles.Premade for some ready-made rules, as well as examples of how to construct them.


import Review.Rule exposing (Rule)
import ReviewPipelineStyles
import ReviewPipelineStyles.Premade
        ( noMultilineLeftPizza
        , noPipelinesWithConfusingNonCommutativeFunctions
        , noPipelinesWithSimpleInputs
        , noRepeatedParentheticalApplication
        , noSemanticallyInfixFunctionsInLeftPipelines
        , noSingleLineRightPizza

config : List Rule
config =
    [ ReviewPipelineStyles.rule <|
            [ noMultilineLeftPizza
            , noSingleLineRightPizza
            , noPipelinesWithSimpleInputs
            , noRepeatedParentheticalApplication
            , noPipelinesWithConfusingNonCommutativeFunctions
            , noSemanticallyInfixFunctionsInLeftPipelines

Try it out

You can try the example configuration above out by running the following command:

elm-review --template SiriusStarr/elm-review-pipeline-styles/example


  • 1.3.1 -- 🐛 Fix aSemanticallyInfixFunction. Previously, it did not check how many args were applied, leading to it flagging things as infix that weren't yet infix, because no args had been applied. Now it requires exactly one arg to be applied.
  • 1.3.0
  • 1.2.0
  • 1.1.0
    • Added premade rules for ease of use! Find them in the ReviewPipelineStyles.Premade module. The documentation for these rules includes the source for how to construct them as a sort of tutorial to learn to create your own.
    • Added StepPredicates. Easily inspect individual steps of pipelines!
    • Updated elm-syntax to avoid mangling fixes involving some lambdas.
    • Minor documentation fixes/clarifications.
  • 1.0.0 -- Initial release