[Chicken-hackers] Unit files for chicken < 3.4.0 (was Re: [Chicken-users] Srfi-19 problems)

[Mario Domenech Goulart]

Hi folks.

On Fri, 7 Nov 2008 10:19:36 -0800 Kon Lovett <address@hidden> wrote:

> On Nov 6, 2008, at 7:56 PM, Timothy Beyer wrote:
>
> The "files" unit came into existence with Chicken 3.4.0 (you are using
> 3.3.0 I see). I suggest creating a empty extension "files" so
> 'require' doesn't barf, upgrading Chicken, or using earlier versions
> of eggs.

This problem is very annoying.  To make the transition to the `files'
unit era transparent to users, I thought about creating a `files' egg
which only installs something[1] when (chicken-version) < 3.4.0,
otherwise nothing is installed and the builtin `files' unit is used.

[1] something like (use posix)

So, when we are using chicken < 3.4.0 a files.so file is installed by
chicken-setup.  The code of this file consists of requiring the
`posix' unit.  When we have `(use files)' in the code, this extension
is used.

When we are using chicken >= 3.4.0, no file is installed.  When we
have `(use files)' in the code, the `files' unit is used.

All the eggs that use procedures from the `files' unit should require
the `files' egg in their .meta file.

Yes, that's an awful hack...  Any thoughts or better alternatives?

Best wishes.
Mario