From: Uncle Mike
Subject: m-expressions? (was: Lisp syntax neverEnding Story)
Date: 
Message-ID: <7j6rba$9s4@fletch.fix.net>
In article <··································@news.demon.co.uk>,
Tony Finch  <···@dotat.at> wrote:
>
>If you read old Lisp documentation you'll find that they planned to
>implement a language based on "m-expressions" (IIRC) that would be a
>simple syntactic transformation into s-expressions. They found that
>writing s-expressions directly was by-and-large tolerable so the
>alternate syntax never happened.

I've read about this before but never in enough detail to figure
out what m-expressions were.  Anybody know?  I'm curious.

-- 
As long as each individual is facing the TV tube alone, formal
freedom poses no threat to privilege.  --Noam Chomsky

From: R. Matthew Emerson
Subject: Re: m-expressions? (was: Lisp syntax neverEnding Story)
Date: 
Message-ID: <87ogixhrov.fsf@nightfly.apk.net>
········@fletch.fix.net (Uncle Mike) writes:

> In article <··································@news.demon.co.uk>,
> Tony Finch  <···@dotat.at> wrote:
> >
> >If you read old Lisp documentation you'll find that they planned to
> >implement a language based on "m-expressions" (IIRC) that would be a
> >simple syntactic transformation into s-expressions. They found that
> >writing s-expressions directly was by-and-large tolerable so the
> >alternate syntax never happened.
> 
> I've read about this before but never in enough detail to figure
> out what m-expressions were.  Anybody know?  I'm curious.
> 

McCarthy's original Lisp paper uses them; I am not sure anyone else
ever did.  (see http://www-formal.stanford.edu/jmc/recursive.html).

-matt
From: Marco Antoniotti
Subject: Re: m-expressions? (was: Lisp syntax neverEnding Story)
Date: 
Message-ID: <lw7lpke5ii.fsf@copernico.parades.rm.cnr.it>
···@nightfly.apk.net (R. Matthew Emerson) writes:

> ········@fletch.fix.net (Uncle Mike) writes:
> 
> > In article <··································@news.demon.co.uk>,
> > Tony Finch  <···@dotat.at> wrote:
> > >
> > >If you read old Lisp documentation you'll find that they planned to
> > >implement a language based on "m-expressions" (IIRC) that would be a
> > >simple syntactic transformation into s-expressions. They found that
> > >writing s-expressions directly was by-and-large tolerable so the
> > >alternate syntax never happened.
> > 
> > I've read about this before but never in enough detail to figure
> > out what m-expressions were.  Anybody know?  I'm curious.
> > 
> 
> McCarthy's original Lisp paper uses them; I am not sure anyone else
> ever did.  (see http://www-formal.stanford.edu/jmc/recursive.html).

"Anatomy of Lisp" does.

-- 
Marco Antoniotti ===========================================
PARADES, Via San Pantaleo 66, I-00186 Rome, ITALY
tel. +39 - 06 68 10 03 17, fax. +39 - 06 68 80 79 26
http://www.parades.rm.cnr.it/~marcoxa
From: Chris Riesbeck
Subject: Re: m-expressions? (was: Lisp syntax neverEnding Story)
Date: 
Message-ID: <riesbeck-0406991243260001@riesbeck.ils.nwu.edu>
In article <··············@nightfly.apk.net>, ···@nightfly.apk.net (R.
Matthew Emerson) wrote:

>········@fletch.fix.net (Uncle Mike) writes:
>
>> In article <··································@news.demon.co.uk>,
>> Tony Finch  <···@dotat.at> wrote:
>> >
>> >If you read old Lisp documentation you'll find that they planned to
>> >implement a language based on "m-expressions" (IIRC) that would be a
>> >simple syntactic transformation into s-expressions.
>
>McCarthy's original Lisp paper uses them; I am not sure anyone else
>ever did.  (see http://www-formal.stanford.edu/jmc/recursive.html).

For quite a few years in the early 70's, MLisp (an Algol syntax
preprocessor for Lisp) was quite popular among subgroups of programmers at
Stanford, and some of us carried it to Yale and used it for a few years.
From: Hartmann Schaffer
Subject: Re: m-expressions? (was: Lisp syntax neverEnding Story)
Date: 
Message-ID: <9fD53.7262$%65.13934@tor-nn1.netcom.ca>
In article <··········@fletch.fix.net>,
	········@fletch.fix.net (Uncle Mike) writes:
> ...I
> I've read about this before but never in enough detail to figure
> out what m-expressions were.  Anybody know?  I'm curious.

McCarthy's LISP1.5 manual (afaik the first generally available book on
Lisp) used a very Algol like notation for code, calling them
m-expressions.  The original intent of the Lisp project was to build a
system that handled m-expressions.  The s-expression code was intended
as internal representation and toto bootstrap the lisp system.  In the
process they discovered that they could live with s-expressions and
theat s-expressions had a few advantages manipulating code that would be 
lost when moving to m-expressions.

Hartmann Schaffer
From: John Atwood
Subject: Re: m-expressions? (was: Lisp syntax neverEnding Story)
Date: 
Message-ID: <7j74fo$odv$1@news.NERO.NET>
>	········@fletch.fix.net (Uncle Mike) writes:
>> I've read about this before but never in enough detail to figure
>> out what m-expressions were.  Anybody know?  I'm curious.
>
Hartmann Schaffer <··@inferno.nirvananet> wrote:
>McCarthy's LISP1.5 manual (afaik the first generally available book on
>Lisp) used a very Algol like notation for code, calling them
>m-expressions.  The original intent of the Lisp project was to build a
>system that handled m-expressions.  The s-expression code was intended
>as internal representation and toto bootstrap the lisp system.  In the
>process they discovered that they could live with s-expressions and
>theat s-expressions had a few advantages manipulating code that would be 
>lost when moving to m-expressions.


I'll add that McCarthy has the original paper online at:
http://www-formal.stanford.edu/jmc/index.html

Recursive Functions of Symbolic Expressions and their Computation by
Machine (Part I), McCarthy, J., CACM, 3:184-195, 1960


John Atwood