[racket] [racket-dev] Survey for DrRacket users related to automatic parentheses behavior

From: Michael Wilber (mwilber at uccs.edu)
Date: Thu Nov 22 20:57:48 EST 2012

I agree with all of these issues and your fix. This would get me back to
using DrRacket's balanced paren option.

A question: What happens when I type ) when I should type ]? E.g.

  [(foo x) "one"]
  [(bar x) "two" |])

where | is the cursor position on the last line there, if I type a )
on accident, will it jump to the outer paren of the (cond ...) block?
Will it interpret the keystroke as a ]? Will it signal an error about
the parenthesis?

Other editors will simply treat the ) as if I'd typed a ]

Nadeem Abdul Hamid <nadeem at acm.org> writes:
> Hello all,
> I've been discussing with Robby a possible improvement of DrRacket's
> "automatic parentheses" behavior and would like to get a sense of others'
> general opinion about this. What follows is a description of my proposal
> and then some concrete questions.
> ;;
> The idea is to have DrRacket automatically skip over automatically-inserted
> closing parens if the user types one while the cursor is right in front of
> one. (The Eclipse Java IDE does this with various types of braces and
> parens, and in the past I've found this very nice and have observed others
> (my students) interact well with such a feature.)
> A concrete example: suppose you are in the process of typing the expression
> "(+ 4 (- 1 2) 3)". After you type the first opening parentheses and the
> characters following it up to the "2", the expression in the editor looks
> like:
>   (+ 4 (- 1 2|))
> where the | represents the cursor's position. Note the two
> automatically-inserted closing parens that are after the cursor right now. With
> the current implementation, you have to then use the right arrow key to
> make the cursor skip past the first auto-inserted ")" and then you can type
> "3". However, that really disrupts the typing process because even if you
> don't type a ) as a habit and then realize you have to delete the extra
> one, you still have to lift and move your finger to the arrow keys area of
> the keyboard or type some other key combination to skip the cursor forward.
> My proposal would be to have it so that if you type ")" in the editor state
> above, it becomes:
>   (+ 4 (- 1 2)|)
> and now you continue typing a space and the 3. Of course, the same thing
> should apply for other types of parens - ( [ { etc.
> I don't know about others, but I actually get annoyed with the curent
> automatic parens feature to the point of disabling it. That is, I like the
> auto-parens feature not because it relieves me from having to type closing
> parentheses - I don't mind that, and I actually tend to do that
> automatically as I'm typing expressions; but the benefit is that it always
> keeps parens balanced while I'm still in the middle of typing an
> expression. However, with the current behavior, it tends to make me type
> extra closing parentheses and have to go back and delete parens to balance
> things up again.
> ;;
> So, the questions:
> 1. Do you use the automatic parentheses feature of DrRacket?
> 2a. If yes, does the proposal above resonate well with you?
> 2b. And, do you think this "smart skipping" of auto-inserted closing
> parentheses should become the intrinsic behavior of the automatic
> parentheses mode, or should it be a separate preference? (i.e. have two
> preference options - the current automatic parentheses one and then a
> subordinate option that enables/disables this skipping over of
> auto-inserted closing parentheses as the user types them)
> 3. If your answer to #1 is "No", why not? (Is it because you find its
> current behavior awkward in some way?)
> Thanks,
> nadeem
> _________________________
>   Racket Developers list:
>   http://lists.racket-lang.org/dev

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