[plt-scheme] Parentheses and color

On some systems (eg windows) you may need esc in stead of alt.
Jos Koot

----- Original Message ----- 
From: <hendrik at topoi.pooq.com>
To: "Eli Barzilay" <eli at barzilay.org>; <plt-scheme at list.cs.brown.edu>
Sent: Wednesday, July 04, 2007 4:00 PM
Subject: Re: [plt-scheme] Parentheses and color


> On Tue, Jul 03, 2007 at 11:01:00PM -0400, Eli Barzilay wrote:
>> On Jul  4, Jean-Pierre Lozi wrote:
>> > 
>> > Indentation is useful when you write code. But sometimes, you have
>> > to rewrite something within some code you already wrote (say, add a
>> > let or a call/cc somewhere), and you don't want to reindent
>> > everything just to close the right parenthesis (because you wouldn't
>> > even want to re-read the code). You'd rather modify the code
>> > quickly, and then reindent it automatically.
>> 
>> Say that you have this:
>> 
>>   (define (foo x y)
>>     (bar (blah x)
>>          y))
>> 
>> and you want to put the body in a parameterize.  IIUC, you'll stick
>> the "(parameterize ([my-param 1])" line, then the closing paren (which
>> you'll look for using colors (which will be confusing, because you
>> added a new paren so the colors don't match)), and then reindent.
>> 
>> Here's what I'll do:
>> 
>> * Put the cursor right before the "(bar ..." line
>> * `M-S-right'        (`M' is usually the `alt' key)
>> * `M-('              (that is, alt+shift+9 on a us keyboard)
>> * type "parameterize "
>> * `M-('
>> * `M-['
>> * type "my-param 1"
>> * `right' `right'    (to go to where the line should break)
>> * `enter'
>> * `M-S-right' `tab'  (to reindent the body)
>> 
>> If you follow this editing sequence, you'll see for yourself that
>> paren counting is never part of the game.  And much more better:
>> parens are there mostly to guide the editor -- in this editing
>> sequence you don't have to even look at them, you only use them to be
>> able to select the body in one key.
> 
> When I did this, I got
> 
> (define (foo x y)
>    S(bar (blah x)
>         y)(parameterize([mu-param 1])
>             S))
> 
> Is that was was desired?
> 
> -- hendrik
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