nil from C

nil from C

[Ian Zimmerman]

Time for next newbie question: how do I create a nil value in C?  I
tried SCM_EOL but that seems to translate into #f.  I use only the scm_
functions so far, so please don't suggest a gh_ function.

-- 
Nothing can be explained to a stone.
Or to a stoned person, either.


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Re: nil from C

[Paul Jarc]

Ian Zimmerman <itz@buug.org> wrote:
> Time for next newbie question: how do I create a nil value in C?

That depends on what you mean by "nil".  There's the symbol 'nil,
which has no special properties in Scheme.  There's #f (SCM_BOOL_F),
which is the Scheme-level false value.  And there's '() (SCM_EOL),
which is the empty list.

> I tried SCM_EOL but that seems to translate into #f.

Strange.  SCM_EOL should be different from SCM_BOOL_F.  How exactly
did you observe this?


paul


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Re: nil from C

[Ian Zimmerman]

Ian> I tried SCM_EOL but that seems to translate into #f.

Paul> Strange.  SCM_EOL should be different from SCM_BOOL_F.  How
Paul> exactly did you observe this?

Yeah, SCM_EOL works.  It was user error - index off by 1.

-- 
Nothing can be explained to a stone.
Or to a stoned person, either.


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