The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: richard@inf.ed.ac.uk (Richard Tobin)
Subject: [TUHS] Future Languages
Date: Tue,  5 Sep 2017 15:41:55 +0100 (BST)	[thread overview]
Message-ID: <20170905144155.4A625150E352@macaroni.inf.ed.ac.uk> (raw)
In-Reply-To: Larry McVoy's message of Mon, 4 Sep 2017 14:59:24 -0700

> So we have some source (that you can have as well, Apache license)
> that handles not strings but vectors of strings (or structs or whatever).
> 
> I need to write up how it works, it's sort of clever.  It stores both
> the size of the vector (always a power of 2) in part of the bits of the
> first entry and the actual length in the other part.  Because we can
> express powers of two in very little space we can support both values
> in a 32 bit unsigned with a max length of used space of around 134M.

I have something similar.  It allocates space for two ints (number
allocated and used) at ((int *)array)[-1] and [-2].

Typical use is

    LTVectorAndInit(char *, names);

    while(...)
      LTVectorPush(names, s);

    for(i=0; i<LTVectorCount(names); i++)
      ... names[i] ...;

    LTVectorFree(names);

-- Richard

-- 
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.



             reply	other threads:[~2017-09-05 14:41 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-05 14:41 Richard Tobin [this message]
  -- strict thread matches above, loose matches on Subject: below --
2017-09-03 14:48 [TUHS] Why Pascal is Not My Favorite Programming Language - Unearthed! Norman Wilson
2017-09-04 21:28 ` [TUHS] Future Languages Steve Johnson
2017-09-04 21:59   ` Larry McVoy
2017-09-05  2:21   ` Noel Hunt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170905144155.4A625150E352@macaroni.inf.ed.ac.uk \
    --to=richard@inf.ed.ac.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).