[Haskell-beginners] questions about "Write yourself a Scheme in 48 hours"

Krzysztof Skrzętnicki gtener at gmail.com
Sat Apr 9 04:00:34 CEST 2011


digit is predefined parser. The implementation is similar to

digit = oneOf "0123456789"

Be sure to read carefully though. At the beginning of Chapter 2 (Parsing) it
reads:

*Parsec provides a number of pre-built parsers: for example, letter and
digit are library functions.*

Also, I recommend downloading the ebook as PDF. It is easier to read that
way.

Best regards,
Krzysztof Skrzętnicki

On Sat, Apr 9, 2011 at 03:45, Michael Litchard <michael at schmong.org> wrote:

> I'm working through "Write yourself a Scheme in 48 hours". I'm on the
> parsing section
> http://en.wikibooks.org/wiki/Write_Yourself_a_Scheme_in_48_Hours/Parsing
>
> and I have a question about the following function
>
> parseNumber :: Parser LispVal
> parseNumber = liftM (Number . read) $ many1 digit
>
> digit looks like a variable, but I don't see it mentioned anywhere.
> Where is the input coming from?
> Is this an example of partial application?
>
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> http://www.haskell.org/mailman/listinfo/beginners
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