[plt-scheme] Re: [plt-edu] Re: conventional syntax

On May 25, 2006, at 2:13 PM, Matthias Felleisen wrote:

>
> On May 25, 2006, at 2:18 PM, Stephen Bloch wrote:
>
>> MAYBE conditionals, using the syntax "if condition then expression  
>> else expression"
>
> I object. I saw conditionals in my high school but they looked like  
> this:
>              -1 if x < 0
>   sign(x) = { 0 if x = 0
>              +1 if x > 0
>
> (which is why I chose cond as the only conditional for the beginner  
> language).
>
> Also, how do you justify boolean w/o conditional?
>
>> There should definitely be a Stepper, which counts "making  
>> implicit multiplication explicit" as a step.
>
> I object again. The insertion of multiplication is purely notational.
>
>> To the teachers reading this: would that be useful?
>> To the PLT geeks reading this: how long would it take to design  
>> and implement?
>
> Look at the honu collection in the svn distribution. I bet it'll be  
> a matter of two days for you to do this (1 day for the brace).

Don't forget to add a few minutes for the stepper.



John Clements

P.S. like Spock didn't say to Kirk: "Admiral, if we go by the book,  
like Lieutenant Saavik, months could seem like minutes..."


P.P.S. Less facetiously: If you plan on adding a stepper, you'll need  
to supply an inverse transformation that maps mzscheme _back_ to your  
syntax. And it'll have to work on partially reduced scheme terms.

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