Checking corectness of parsers in Haskell

Question

For a uni assignment I need to write parsers in Haskell, right now I have the following parser i think is correct:

parseYear :: Parser Char Year
parseYear = Year <$> ...

I want to check if it works, for example with > parseYear "2004" in ghci. this command is not valid, but i there another way to quickly check if a parser I'm writing is correct?

Edit: Example, for the parser:nesting :: Parser Char Int, this would be what i want

Depending on what `Parser` is, you need some function (`runParser`?) to *extract* a function that can be called on a string. `runParser nesting "()(())()"`. (And don't post images; that picture could easily be entered as regular text.) — chepner, Dec 02 '22 at 18:22
@FyodorSoikin this gives an error: "The function parseYear is applied to one value argument, but its type Parser Char Year' has none" — Jord van Eldik, Dec 02 '22 at 18:40

score 1 · Accepted Answer · answered Dec 02 '22 at 18:40

From your comment responses, I understand that you're using the uu-tc library, but your Parser type does not come from ParseLib.Simple, because it's not a function.

This means your Parser type must come either from ParseLib.Parallel or from ParseLib.Abstract. Both of those modules define their Parser type as data, and both expose a parse function - here's the one from ParseLib.Abstract and here's the one from ParseLib.Parallel.

Both these parse functions have the same shape: they take a Parser as first parameter and an input list as second. So that's how you would call it:

import ParseLib.(either Parallel or Abstract).Core (parse)

> parse parseYear "2004"

Checking corectness of parsers in Haskell

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