[racket] Request feedback on a boggle solver

Hi Carl,

I've cleaned up the code a bit and added tests to all the functions. Do you
mind taking another look? Don't hesitate to give comments even if they are
trivial. The more the better. I'm a total scheme/racket beginner. Thanks.

https://github.com/jduan/boggle_scheme/blob/master/boggle.rkt

In the mean time, I'm going to take a look at Jay McCarthy's solution. I
didn't want to look at his code before because I didn't want his code to
affect my refactoring.


Thanks,
Jingjing


On Sat, Sep 21, 2013 at 9:14 PM, Carl Eastlund <cce at ccs.neu.edu> wrote:

> Looking forward to to your followup!
>
> Carl Eastlund
>
> P.S. copying to the mailing list so everyone's in the loop.
>
> On Sat, Sep 21, 2013 at 8:25 PM, Jingjing Duan <duanjingjing at gmail.com>wrote:
>
>> Hi Carl,
>>
>> Thanks for your great feedback. Let me try to rewrite the code, this time
>> by following the recipes from HTDP. Will send out another email once I'm
>> ready!
>>
>> Thanks,
>> Jingjing
>>
>>
>> On Sat, Sep 21, 2013 at 10:25 AM, Carl Eastlund <cce at ccs.neu.edu> wrote:
>>
>>> On Sat, Sep 21, 2013 at 12:09 PM, Jingjing Duan <duanjingjing at gmail.com>wrote:
>>>
>>>> Hi,
>>>>
>>>> I've been reading HTDP and I'm about half way through. To apply what
>>>> I've learned in the book to a bigger exercise, I decided to write a boggle
>>>> solver.
>>>>
>>>> You can find the code here:
>>>> https://github.com/jduan/boggle_scheme/blob/master/boggle.rkt
>>>>
>>>> Any feedback is greatly appreciated. I'm specifically looking for
>>>> feedback on:
>>>>
>>>> 1. Did I break the problem into right components?
>>>> 2. How can I make the code more idiomatic?
>>>>
>>>
>>> If you're halfway through HtDP, you should know the value of data
>>> definitions, contracts, and test cases.  I don't see any of those in your
>>> program.  That makes it very hard to tell what's going on in the code, and
>>> whether it's doing the right thing.  Adding them after the fact should
>>> improve your code's readability.  Adding them earlier -- during the design
>>> process of the code itself -- helps break things down into components in a
>>> natural way.
>>>
>>>
>>>> 3. Why is code so slow? It can take minutes to solve a 4 by 4 board.
>>>> The same board can be solved by a ruby program I wrote in much less time,
>>>> like a few seconds. I know recursive functions are a big reason but is
>>>> there anything?
>>>>
>>>
>>> "Recursive functions" have nothing to do with the kind of slowdown
>>> you're seeing.  Your program is simply doing too much work.  Start adding
>>> simple test cases for your functions and you may start to get a clearer
>>> idea of where a lot of the work is being done.  The process of adding test
>>> cases may also suggest simpler ways to structure your program, both in
>>> terms of making it more idiomatic and in terms of doing less work.
>>>
>>> You might get a lot out of restarting this boggle exercise from the top
>>> down, starting with the function find-all-words and going through the
>>> design recipe step by step.  You may be surprised how different the result
>>> is from what you've written, and how much more natural the solution you get
>>> is.  In my own experience, it is also a much quicker process than taking
>>> something written as a whole without the design steps, and trying to add
>>> them in after the fact.
>>>
>>> However you proceed, please feel free to share your results and any
>>> other questions you have with the list.  We love hearing about stuff like
>>> this!
>>>
>>>  Thanks,
>>>> Jingjing
>>>>
>>>
>>> No problem.  Glad to see you're interested in HtDP and Racket!  Good
>>> luck!
>>>
>>> --Carl
>>>
>>
>>
>
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