[San-Diego-pm] Meeting today (Monday, March 13th, 2006)

[Tkil]

In attendance were: Joel, Emile, David, Menolly, and me.

Notes from memory:

* Joel and I discussed GPS geodes and datums (that's /got/ to be
  wrong!), especially w.r.t. his experience of not having google maps
  grids mesh with what he was observing in the field with his GPS
  unit.

  No conclusions were made, but I did link to this pic, made from a
  bike ride I did last weekend and www.gpsvisualizer.com

    http://scrye.com/~tkil/misc-pics/med/med-bike-ride-2006-03-04.html

  Further readings:

    http://en.wikipedia.org/wiki/Geodesy
    http://en.wikipedia.org/wiki/Datum
    http://www.dbartlett.com/index.htm#setup
    http://www.nb.net/~resteele/newsites/gpsdatum.htm

  FWIW, my GPS unit (Garmin eTrex Vista) has a setting for which datum
  to use (Main Menu -> Setup -> Units -> Map Datum) with... a *lot* of
  options.  J reports that his GPS unit and his survey maps (mostly
  NAD'27 datum) seem to coincide, so good for him -- but it's
  something to watch out for.

  (In this particular case, he's looking for a particular location; it
  sounds like he needs to ascertain which datum that location was
  surveyed against, and either set his GPS for that datum, or
  translate the given location to the datum used by his current GPS
  settings and maps.)

* We discussed some aspects of the inside-out object pattern, and I
  tried to come up with an example on the spot.  Sadly, between having
  little creativity and having spent *WAY* too much time with java
  lately, it took me a while, but I eventually had a primitive example
  that demonstrated the three advantages of i-o objects:

  - compile-time field name checking

  - lexical hashes to hide data within a package

  - subclass field names can't collide with superclass field names

  The example can be found at:

    http://scrye.com/~tkil/perl/sdpm-20060313/

  Note that this does *not* implement the necessary DESTROY functions,
  so it will leak memory.  Presumably with a leg raised.

  I actually have lingering questions over the proper way to implement
  DESTROY; the way described in his internal presentation and in the
  article seem to want to call grandparent class destructors too many
  times, but I need to stare at it some more before I'm sure.

* Emile had an interesting problem where he was trying to factor
  presentation away from business / processing logic when the subject
  is a highly recursive structure (in his case, physical locations,
  mount points, nfs shares, filenames, oh my!).

  I suggested the "Visitor" pattern from the "gang of four" book:

    http://en.wikipedia.org/wiki/Visitor_pattern

  And there is indeed a Simple::Tree::Visitor class (Emile is using
  S::T in his current work.)  I was also a sick little monkey and
  recommended XSLT, but I'm a bastard like that.  We look forward to
  hearing the results of his experimentation.  (Hint hint.)

Odds and sods:

* Joel mused about upgrading his hiking GPS.  I'm happy with my Garmin
  eTrex Vista, although I lust after the eTrex Vista C and the new Cx
  model (the latter having an expandable memory slot).  Or their
  one-notch-higher GPSMAP 76Cx.  Mmm.  Unfortunately, entry into those
  clubs is in the 300$ range; J was looking more at lightly used
  models in the 50$ range.  Fair enough.

* J also mentioned my editing environment on my [work related! 
  honest!] windows laptop.  I've managed to get 95% of my unixy
  environment on this box, mostly through:

    http://www.chiark.greenend.org.uk/~sgtatham/putty/
      A free SSH client + VTxxx/xterm emulator for windows (also
      pagaent, an ssh-agent)

    http://www.gnu.org/software/emacs/windows/ntemacs.html
      GNU Emacs ported to win32

    http://www.cvsnt.org/
      CVS for nt

    http://www.cygwin.com/
      A port of many common unix utils (i use mostly grep and perl) to
      windows, as well as a bash shell.

  I also installed a bunch of Java utils (JDK, Tomcat, NetBeans) to
  c:\java; it's probably best to avoid paths with any spaces for that
  stuff.

  Anyway, if anyone else is an emacs fan that would like a comfortable
  light-on-dark editing experience, my current _emacs file is
  available at:

    http://scrye.com/~tkil/perl/sdpm-20060313/_emacs

  Lots of cruft has accumulated there, but the font-lock and faces
  bits are releavant for the editing experience I was "showing off" at
  the meeting.

* J further related some issues he was having sending mail to Juno
  e-mail subscribers.  Indications pointed to him being on the
  Spamhaus.org RBL, but that hadn't been fruitful.

  The best we could suggest was for him to get a juno account himself,
  and see what it took for him to receive mail from his external
  accounts.

Did I miss anything?  Updates and corrections welcome.

Happy hacking,
t.