From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,24d7acf9b853aac8
X-Google-NewGroupId: yes
X-Google-Attributes: gida07f3367d7,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news1.google.com!news3.google.com!feeder.news-service.com!85.214.198.2.MISMATCH!eternal-september.org!feeder.eternal-september.org!.POSTED!not-for-mail
From: Ludovic Brenta <ludovic@ludovic-brenta.org>
Newsgroups: comp.lang.ada
Subject: Re: S-expression I/O in Ada
Date: Fri, 13 Aug 2010 17:52:28 +0200
Organization: A noiseless patient Spider
Message-ID: <87eie2jyrn.fsf@ludovic-brenta.org>
References: <547afa6b-731e-475f-a7f2-eaefefb25861@k8g2000prh.googlegroups.com>
	<87aap6wcdx.fsf@ludovic-brenta.org>
	<87vd7jliyi.fsf@ludovic-brenta.org>
	<699464f5-7f04-4ced-bc09-6ffc42c5322a@w30g2000yqw.googlegroups.com>
	<87ocdbl41u.fsf@ludovic-brenta.org>
	<i3q86h$2o0n$1@adenine.netfront.net>
	<e7e38ba7-bed6-4780-9b85-813576e408e3@f6g2000yqa.googlegroups.com>
	<i3s4rh$a93$1@adenine.netfront.net>
	<318d4041-eb01-4419-ae68-e6f3436c5b66@i31g2000yqm.googlegroups.com>
	<i41fr4$1s0n$1@adenine.netfront.net>
	<383ec00d-1f62-4d2f-b501-cedaeaa4b3c4@t2g2000yqe.googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Injection-Date: Fri, 13 Aug 2010 15:52:28 +0000 (UTC)
Injection-Info: mx03.eternal-september.org;
 posting-host="49Cd3UBGonzbsZffKKSfQg";
	logging-data="27731"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX1+ypexOkn+lPgin/hpT+v98"
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux)
Cancel-Lock: sha1:9NCbwdzfVjbq/hZEM3235CnwNgs=
	sha1:ZxWZr5zGW9uBhL6YQCq3GNCq/UM=
Xref: g2news1.google.com comp.lang.ada:13225
Date: 2010-08-13T17:52:28+02:00
List-Id: <comp.lang.ada>

Natacha Kerensikova <lithiumcat@gmail.com> writes on comp.lang.ada:
> What I found tricky is the "single operation" part. Building 8 nodes
> in a single operation does look very difficult, and while Ludovic's
> trick of building them from an encoded string is nice, it makes we
> wonder (again) about the point of building a S-expression object
> before writing it while it's simpler and clearer to write strings
> containing hand-encoded S-expressions.

The only use case for constructing an S-Expression tree in memory and
then writing it out is when the S-Expression is very dynamic.  For
example, when you want to save the state of your application, e.g. the
cache of a web browser, in a structured way.  Or when you want to save a
tree, the contents and structure of which are unknown in advance.

If the S-Expression is static or mostly so, then by all means write it
by hand.

-- 
Ludovic Brenta.