[racket] bracket conversion?

I think one way to do it would be to use read-syntax to get the
expression, but then also put the file into a string. Walk the
expression and look for patterns that you want to change rounds to
squares and then mutate the string and write the file back out again.
Use the position field of the syntax object to tell you where to
mutate the string.

You could even take a check-syntax like approach (it is more complex,
tho) and fully expand the program. Then, when you find 'cond' in the
origin field of some syntax object you can be sure it really is
racket/base's cond and not some other thing like, eg

(lambda (cond) (cond 3 (+ 1 2)))

Robby

On Tue, Nov 20, 2012 at 5:09 PM, John Clements
<clements at brinckerhoff.org> wrote:
>
> On Nov 20, 2012, at 11:28 AM, Eric Tanter wrote:
>
>> Thanks John, that's very helpful!
>>
>> Any idea about a whole-file racketify in DrRacket?
>
> That's a toughy. What you want is to be able to invert (read-syntax). It seems to me that such a thing should be possible in many of the racket languages, but I'm not aware of an implementation.
>
> Actually, thinking about it harder, I suppose you have the original string text of the file, as well, so that makes it a hugely easier; you just need a predicate on the (un-expanded) syntax objects that can tell you whether a syntax list should have square or round brackets.
>
> So, here's the $64K question: can you specify precisely which places need to be changed? If so, it sounds like this is do-able.
>
> John
>
>
>
>>
>> -- Éric
>>
>>
>> On Nov 20, 2012, at 3:16 PM, John Clements wrote:
>>
>>>
>>> On Nov 20, 2012, at 10:01 AM, Eric Tanter wrote:
>>>
>>>> Hi,
>>>>
>>>> I'm converting code written with only standard parentheses, introducing squared ones where appropriate.
>>>>
>>>> This is obviously not very fun (I'm converting all of OOPLAI), and it would be great if there'd be a way to select an open paren and "convert" it so that the matching closing paren is changed automatically.
>>>>
>>>> Is this feasible?
>>>>
>>>
>>> I'm pretty sure Sam and I added this binding last year. C-c C-[ ? I think you can look it up in the keybindings.
>>>>
>>>
>>> John
>>>
>>
>
>
> ____________________
>   Racket Users list:
>   http://lists.racket-lang.org/users
>