Typed query params

[nukisman]

Now we match query parameters like this

 TypedParams <$ lit "typedParams" <*> paramInt "i" <*> paramBool "is" <*> paramNum "n"`

And create custom typed decoder using paramWith

[CLAassistant]

All committers have signed the CLA.

[garyb]

This looks like a pretty good addition to me. Anyone have any comments?

I think it'd perhaps be nicer to simplify paramWith to deal with Either? I would think the kind of parsing done in there typically would be simple enough that the extra structure in V (Free MatchError) isn't required.

paramWith :: forall a. (String -> Either MatchError a) -> String -> Match a

[safareli]

parseFloat("Infinity") // Infinity so should also add && isFinite n

[safareli]

We are getting a bit of a repetition here (look at toNum, toBool, ... and num, int, bool matchers)

Ideally same toNum, toBool, ... functions could be reused in definition of num, int, bool and param*. for example:

lit :: String -> Match Unit
lit input = eitherMatch $ path ExpectedPathPart <#> \i -> if i == input then Right unit else Left $ UnexpectedPath input

str :: Match String
str = path ExpectedString

path :: MatchError -> Match String
path err = Match \route ->
  case route of
    Cons (Path input) rs ->
      pure $ Tuple rs input
    _ ->
      invalid $ free err


num :: Match Number
num = eitherMatch $ path ExpectedNumber <#> asNum >>> note ExpectedNumber
paramNum :: Match Number
paramNum = paramWith $ asNum >>> note ExpectedNumber

bool :: Match Boolean
bool = eitherMatch $ path ExpectedNumber <#> asBool >>> note ExpectedBoolean
paramBool :: Match Boolean
paramBool = paramWith $ asBool >>> note ExpectedBoolean

We can do this in different PR too.