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From: dorai@titan.rice.edu (Dorai Sitaram)
Newsgroups: comp.lang.scheme
Subject: Re: On the standard behavior of "load"
Message-ID: <7490@brazos.Rice.edu>
Date: 8 May 90 16:47:19 GMT
References: <3601@jato.Jpl.Nasa.Gov>
Sender: root@rice.edu
Organization: Rice University, Houston
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In article <3601@jato.Jpl.Nasa.Gov> brian@granite.Jpl.Nasa.Gov (Brian of ASTD-CP) writes:
>I would like to start a discussion concer-
>ning the Scheme essential procedure "load". The
>Scheme definition, R3.99RRS, states that the re-
>turn value of "load" is unspecified. However, I
>[...]
>With many implementations of Scheme, load returns
>#f when the file passed to it is not found, and #t
>otherwise. I think this ought to be the standard
>behavior of load.  [...]

Wouldn't you be satisfied with just `file-exists?'?  Almost every
Scheme I've come across provides this procedure -- though RRRS doesn't
include it.  Obviously, `file-exists?'  and the unspecified-returning
`load' provide the capability you desire (load-module, etc.).

(define load1 
  (lambda (f) (if (file-exists? f) (begin (load f) #t) #f)))

(NB: The #f/#t `load' doesn't make `file-exists?' superfluous.  The
latter provides the ability to say that a file exists without having
to load it too.)

--dorai