[plug] Community Seminars

[Bernd Felsche]

On Friday 18 June 2004 07:49, Cameron Patrick wrote:
> Bernd Felsche wrote:
> > Try to explain the difference between program and data. Should be
> > easy if you're in a library.

> I don't think it's a particularly easy distinction to make.  Is HTML
> code a programme or data?  How about TeX?  What about Docbook which

Programmes are run; data are stored.

HTML is *never* a programme. Nor are TeX and Docbook, strictly speaking.

Just because it's written in a language, doesn't make it a
programme.

> can be used to generate the other two?  Python or Java code with
> embedded docstrings?  Literate programmes like TeX, Metafont or ifupdown?

You're thinking too much.

Bash, Perl, Python, Java, Basic, etc are intepreted by programmes
that are designed to give those languages wide access to the
machine's facilities. That's different to languages such as TeX,
HTML, PostScript, OO.o etc where the application program is designed
for a particular task; not one of system control but solely the
control of the application's functions.

A program is something that the system executes "directly"; data
are what programs use. Data may be in the form of files, streams (as
in serial/network data), shared memory or similar storage.

GUIs tend to obscure the distinction as they are able to associate
types of data with programs that use those types of data.

Hiding complexity is good. Obscuring functionality is bad.

-- 
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