[Haskell-cafe] "Write Yourself a Scheme in 48 Hours"

Shannon -jj Behrens jjinux at gmail.com
Fri Feb 2 15:30:46 EST 2007


On 2/1/07, Bryan O'Sullivan <bos at serpentine.com> wrote:
> Shannon -jj Behrens wrote:
> > I'm going through the "Write Yourself a Scheme in 48 Hours"
> > <http://halogen.note.amherst.edu/~jdtang/scheme_in_48/tutorial/overview.html>
> >
> > tutorial.  I like it a lot, but I have some concerns.  Are the
> > exercises in the tutorial known to be solvable by mere mortals?
>
> The answer seems to be "yes, iff the mortals in question have grasped
> the basics of monads, so they can fill in the gaps in the exposition."
>
> > For instance:
> >
> > "Rewrite parseNumber using...explicit sequencing with the >>= operator"
> > http://halogen.note.amherst.edu/~jdtang/scheme_in_48/tutorial/parser.html#symbols
> >
> > There aren't any examples of using >>= previous to this question.
>
> There's a peculiar mixture of assumptions in the article.  He treats
> monads breezily, as if they're a given; but pattern matching (much more
> basic) receives some rather more detailed exposition.  And he glosses
> over ">>", but doesn't mention the rewrite rule from "a<-x" to "x>>=\a->".
>
> So don't beat yourself up.  The tutorial is missing a few bits and pieces.

Thanks.  That's all I needed to hear :)

-- 
http://jjinux.blogspot.com/


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