Re: How do thread locations get updated?

[Jamison Hope <jrh at theptrgroup dot com>]

Try using set! instead of define. define is probably creating a new
binding that shadows gnu.text.PrettyWriter:lineLengthLoc.
fluid-let will work, too, if you don't want the change to be
permanent:

#|kawa:1|# (gnu.text.PrettyWriter:lineLengthLoc:get #!null)
#!null
#|kawa:2|# *print-right-margin*
#!null
#|kawa:3|# (set! *print-right-margin* 20)
#|kawa:4|# *print-right-margin*
20
#|kawa:5|# (gnu.text.PrettyWriter:lineLengthLoc:get #!null)
20
#|kawa:6|# (fluid-let ((*print-right-margin* 10))  
(gnu.text.PrettyWriter:lineLengthLoc:get #!null))
10
#|kawa:7|# (gnu.text.PrettyWriter:lineLengthLoc:get #!null)
20


-Jamie

On Sep 29, 2011, at 7:04 PM, Charles Turner wrote:

> Hi,
> I'm trying to see a dynamic change in some of the ThreadLocation's
> defined in PrettyWriter.
> As an example, lineLengthLoc seems to always be null. It's "Scheme
> name", if it's sensible to call it that, is *print-right-margin*.
> Which is setup in Scheme using,
>
> defAliasStFld("*print-right-margin*", "gnu.text.PrettyWriter",  
> "lineLengthLoc");
>
> I expect that having evaluated (define *print-right-margin* 20) in the
> REPL, lineLengthLoc.get(null) would return 20, and not null again.
>
> What am I missing?
>
> Thanks,
> Charles.

--
Jamison Hope
The PTR Group
www.theptrgroup.com