[racket] letoverlambda

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Sat Nov 20 21:33:57 EST 2010

For my part, I don't mind dissing hygiene; I certainly don't think
that the current state of the art in hygenic macro expanders is the
best we can do. BUT, I found the small sampling that I read of Let
Over Lambda to be fairly ignorant in some ways and quite strange in
others (like the paragraph that complained about booleans in Scheme;
it didn't make much sense to me).

Anyways, to your actual question: my answer would be that most macros
I know are hygenic. Ie, if you have to pick a default for variables
introduced by a macro, hygenic is the right one.


On Sat, Nov 20, 2010 at 8:01 PM, Greg Hendershott
<greghendershott at gmail.com> wrote:
> I've only skimmed/sampled some of On Lisp, and even less of Let Over
> Lambda. But the main theme of both seemed to be: Macros are an
> important higher level of programming, but under-appreciated,
> under-utilized, under-understood (stood?), and "under-booked". Hence
> these books.
> Anaphoric macros are deliberately unhygienic. But I didn't get the
> impression that all or even most of the macro techniques were
> unhygienic. Am I wrong and didn't get deep enough into the books?  To
> put it another way, is the negative reaction here due to him dissing
> hygiene, or is it reflective of a deeper and broader disagreement with
> the entire approach of putting macros on a pedestal?
> BTW I'm asking this innocently, genuinely not knowing the answer,
> curious what more experienced people think.
> On Sat, Nov 20, 2010 at 10:53 AM, Carl Eastlund <cce at ccs.neu.edu> wrote:
>> On Sat, Nov 20, 2010 at 9:46 AM, Hendrik Boom <hendrik at topoi.pooq.com> wrote:
>>> On Sat, Nov 20, 2010 at 08:42:57AM -0500, Shriram Krishnamurthi wrote:
>>>> I haven't seen this book mentioned here before, so:
>>>> http://letoverlambda.com/
>>>> It is, well, a very particular perspective on things, but I've heard
>>>> people speak well of it.
>>> It looks interesting.  Very unSchemeish, though.  Chapter 6, on
>>> anaphoric macros, seems to celebrate unhygienicity.
>>> -- hendrik
>> The following passage is particularly unsettling.
>> "Even the vast majority of Scheme systems, the platform that has
>> experimented the most with hygiene, provide unhygienic defmacro-style
>> macros—presumably because not even Scheme implementors take hygiene
>> very seriously. Like training wheels on a bicycle, hygiene systems are
>> for the most part toys that should be discarded after even a modest
>> level of skill has been acquired."
>> --Carl
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