[R6RS] proposed library/syntax-case changes

Michael Sperber sperber at informatik.uni-tuebingen.de
Mon Aug 28 10:47:05 EDT 2006

dyb at cs.indiana.edu writes:

> * flush "for eval".  Aziz pointed out correctly that requiring "for eval"
>   to be present in the library header effectively prevents people from the
>   full freedom to exercise functionality that is present in most other
>   languages, like C (with dlopen/dlsym) and Perl (with dynamically loaded
>   modules), putting Scheme at a competitive disadvantage.  This means, for
>   example, that we can't implement a Linux-like kernel or Apache-like web
>   server with dynamically loadable modules.  We can't even use the system
>   to implement a portable interactive Scheme REPL and interpreter with
>   dynamically loaded libraries. 

Arguably, `eval' is completely the wrong mechanism to use for
implementing this kind of functionality.  I don't understand the
consequences of this change---what libraries will then be available
for use with `eval'.  You say:

>   For the many applications that don't use eval, removing the "for eval"
>   declaration and corresponding restriction does not impact an
>   implementation's ability to generate self-contained applications. 

But it seems fairly obvious that a self-contained application *will*
impose restrictions.  Or am I missing something important?

Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla

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