Selective Applicative Functors in WebCheck
WebCheck uses a version of PureScript for specifications in testing web applications, which I'll refer to as "the language" in this document.
A specification includes a top-level definition called
must be a pure expression of type
Boolean. The interpreter of the language
does not allow effects (the
Effect type in PureScript, formerly known as
Eff). But there are a few built-in constructs that are at least backed by