On the other hand, you can pretty much just learn Haskell to learn PureScript. All of the differences fit onto a single small docs page: https://github.com/purescript/documentation/blob/master/lang...
Also, these days no one want to learn Haskell just for sake of building UI. Just do it in JavaScript or TypeScript, far far far easier pill to swallow.
Yes I learned Haskell, Elm, and Rust