Mon Aug 24 20:32:40 CEST 2009

JOY: Intensional quotation

Both intensional and extensional quotations can be _constructucted_ by
building larger objects that contain other quotations as subparts, but
only intensional quotations can be _deconstructed_ i.e. interpreted as
a list.

Because the use of extensional quotation requires two different types
with different operators, Manfred concludes[1] that ``On the whole,
then, it does seem preferable to have quotation as an intensional

PF (and Scat in Staapl) do it differently to be able to compile
quotations to a more efficient form.  MetaOcaml does it differently to
not loose well-typed guarantees.  In general it seems to me that
extensional quotation is the sensible default: loose reflective object
language expressivity to gain meta language expressivity.

[1] http://www.latrobe.edu.au/philosophy/phimvt/joy/j07rrs.html
[2] http://en.wikipedia.org/wiki/Intensional_definition
[3] http://ccl.clozure.com/irc-logs/scheme/2008-10/scheme-2008.10.22.txt