Re: Closures versus objects

On 2/15/07, Mike Newhall <[email protected]> wrote:
>
>         One topic that seems to have been a perennial or at least occasional topic of discussion is the relationship between closures and objects and their substitutability.  Chistian Queinnec mentions this dichotomy / competition in Lisp In Small Pieces.  I have not yet had the experience of witnessing such a fight so perhaps it would be educational to instigate one here. :-)

I'm pretty sure Anton van Straaten had the last (or at least best)
word on that on this list several years ago:

"

  The venerable master Qc Na was walking with his student, Anton.  Hoping to
prompt the master into a discussion, Anton said "Master, I have heard that
objects are a very good thing - is this true?"  Qc Na looked pityingly at
his student and replied, "Foolish pupil - objects are merely a poor man's
closures."

  Chastised, Anton took his leave from his master and returned to his cell,
intent on studying closures.  He carefully read the entire "Lambda: The
Ultimate..." series of papers and its cousins, and implemented a small
Scheme interpreter with a closure-based object system.  He learned much, and
looked forward to informing his master of his progress.

  On his next walk with Qc Na, Anton attempted to impress his master by
saying "Master, I have diligently studied the matter, and now understand
that objects are truly a poor man's closures."  Qc Na responded by hitting
Anton with his stick, saying "When will you learn? Closures are a poor man's
object."  At that moment, Anton became enlightened.

"

http://people.csail.mit.edu/gregs/ll1-discuss-archive-html/msg03277.html