[racket] How to get paren highlighting with online compilation highlighting too?

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Thu Nov 29 12:20:15 EST 2012

I think that makes sense. Indeed, I could arrange for the highlights
to be drawn first (before the text) and use non-1 alphas to achieve
this affect when highlights are layered. Let me think more about this
and I'll give it a try at some point.


On Thu, Nov 29, 2012 at 10:04 AM, Grant Rettke <grettke at acm.org> wrote:
> On Thu, Nov 29, 2012 at 7:59 AM, Robby Findler
> <robby at eecs.northwestern.edu> wrote:
>> The way those highlights work, you are going to see either one or the
>> other and I think it gets more confusing when the paren highlights
>> obscure the error highlights (indeed, we have had PRs in the past
>> claiming that the error highlighting was broken when the priorities
>> were reversed).
>> Unless you have an idea on how to show both?
> What I was thinking was doing something like this:
> 1. Say there is a section that is highlighted like this (foo (bar
> (baz))) ;; (this is not complicated but imagine that it is)
> 2. The highlighter is highlighting the whole in ERR_COLOR.
> 3. And you need to fix something and you need to put the cursor in the
> right place. Of course I can't reproduce the situation that made me
> think of this hence the simple example. Anyway you want paren
> highlighting.
> 4. There is a some color already defined for highlighting matching
> parens MP_COLOR. Error highlighting won't use this.
> 5. Instead it would make MP_ERR_COLOR which is ERR_COLOR but take down
> the value (the V in HSV I looked it up) so that it is still clearly an
> error, but there is some visual distinction.
> Maybe this is an edge case? I can't even create a situation where this
> makes sense.
> But anyway the idea is that it is clearly an error, but there is a
> subtle difference to see paren background highlighting.
> Just an idea. I would code it up but it would take me a week. That
> said I would be happy to try.

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