Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Stefan Monnier <monnier@iro.umontreal.ca>
Newsgroups: comp.lang.lisp
Subject: Re: infix via code walker hook.
Date: Fri, 04 Apr 2025 14:17:20 -0400
Organization: A noiseless patient Spider
Lines: 30
Message-ID: <jwvldsfrecv.fsf-monnier+comp.lang.lisp@gnu.org>
References: <20250331141507.905@kylheku.com> <20250401201007.528@kylheku.com>
	<20250403192220.35@kylheku.com>
MIME-Version: 1.0
Content-Type: text/plain
Injection-Date: Fri, 04 Apr 2025 20:17:20 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="c4785f6db9d201abe0a742add2baccc1";
	logging-data="2797"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/MmN2Lt5I/ASGPi6F4d9GUdtEx12h4nqs="
User-Agent: Gnus/5.13 (Gnus v5.13)
Cancel-Lock: sha1:UMKYDpFwD9lIfj9NgyY6GkeooWw=
	sha1:ZJ+OHhiw38UDV9p73FdEiDUHuFI=
Bytes: 1740

>   1> (parse-infix '(sin a + b + c + d))
>   (sin (+ (+ (+ a b) c)
>           d))
>
> But, if we put parentheses on the operand of sin, then it's no longer
> the unary sin, but a function call with that argument:
>
>   2> (parse-infix '(sin (a) + b + c + d))
>   (+ (+ (+ (sin a) b)
> 	c)
>      d)

For someone coming from "statically typed functional programming", this
is *very* weird.
All those languages (Haskell/OCaml/SML/Coq/Idris/Agda/...) treat

    (sin a + b + c + d)

the same as

    (sin (a) + b + c + d)

> I think it is already better than SRFI-105 curly braces and some
> other systems.

A related effort was Honu:
https://users.cs.utah.edu/plt/publications/gpce12-rf.pdf


        Stefan