Package

purescript-polyform

Repository
paluh/purescript-polyform
License
BSD-3-Clause
Uploaded by
paluh
Published on
2020-03-07

Validation toolkit plus alternative codec type formulation.

Sorry for this sparse docs. I hope to extend them soon. Till then it is just better to take a look at the real world examples (json duals etc.) in the lambdaterms/purescript-polyform-validators repo.

Core types

Validator

It provides an Applicative instance which allow composition in the Reader spirit - all Validators "work" on the same input. It is accumulative because it is build on top of V. There is also a Category instance which allows you to build validation chains combining this applicative steps.

newtype Validator m e i o = Validator (Star (Compose m (V e)) i o)

Exceptor

This type is nearly Star (Except e m) but there is no Semigroup e constraint in its Alt instance (consistent with Either).

newtype Exceptor m e i o = Exceptor (Star (ExceptT e m) i o)

Dual

Additionally it provides basic types for bidirectional validation and serialization through Polyform.Dual type.

data DualD p i o o' = DualD (p i o') (o  i)

newtype Dual p i o = Dual (DualD p i o o)

Name

polyform initialy was intended to provide some basic mechanism for html form validation. It was polyomrphic on the form type hence the name. After the last rewrite this name has probably no sens any more, but you now - "naming is the..."