[plt-scheme] Re: pretty html source

From: Eli Barzilay (eli at barzilay.org)
Date: Fri Nov 14 10:05:56 EST 2008

On Nov 14, Dave Gurnell wrote:
> Oh absolutely. The "simple" version I was referring to was a naive
> one you suggested above.

FWIW, the code that I used would do something like this with the
previous example:

  <p><ul>              ; no space after the <p>, but the next line
      <li>blah</li>    ; has four spaces because it's two levels
      <li>blah</li>    ; in

This means that for each html tag I need to keep information about
whether whitespace being ignored (for example, <ul>), not ignored
(<li> and <p>), or "very not ignored" as in <pre>.  It was a mess, and
definitely too much work for too little profit.

> I was previously content to rely on pretty-printing plugins for
> Firefox to do my formatting for me (the "View Source Chart"
> extension is quite good). I'm really impressed with PPrint, though,
> so now I'm now tempted to give some full-featured Scheme code a try.
> Come to think of it (and as an aside), there *is* a reason I haven't
> put pretty printing into Mirrors yet... the compile-time rendering
> features make it difficult to do. By default, something like:
>    (xml (p "Hi " (b ,name)))
> is macro-transformed to the equivalent of:
>    (xml (!raw "<p>Hi <b>") ,name (!raw "</b></p>"))
> This feature can be turned off but !raw blocks are always available
> to the programmer and it's not obvious now to handle them in pretty
> printed output. Suggestions welcome.

Looks like you'll have to translate that to raw strings that will
appear one line, with a `break' tokens that carry the indentation
level that they must go in.  That's for the "simple approach"; for the
real pprint way you'll probably need to add soft and hard breaks, and
probably even breaks at different levels of soft/hard.

So my opinion is that this is even more work for an even less gain
(since it's even less likely that someone will take generated pages
and edit them).  The only utility I can see in this is debugging --
and things like browser view of the xml tree or a dom inspector are
much better at doing these things anyway.

(And that's really pointing at the ridiculousness of the xml syntax
with its "human readable" redundancy -- it's only a question of time
until no manually-written html pages exist.)

          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!

Posted on the users mailing list.