Re: [Scheme-reports] Why define-library requires a explicit begin form?

[張書瀚 <zrqsmcx@x>]

Now it makes sense for me, Thank you!

2013/5/13 Taylan Ulrich B. <taylanbayirli@x>

張書瀚 <zrqsmcx@x> writes:

> Here is a example in r7rs-draft-9.pdf:
> (define-library (example life)
> (export life)
> (import (except (scheme base) set!)
> (scheme write)
> (example grid))
> (begin
> (define (life-count grid i j)
> ...)
> ...))
>
> why not:
> (define-library (example life)
> (export life)
> (import (except (scheme base) set!)
> (scheme write)
> (example grid))
> (define (life-count grid i j)
> ...)
> ...)
>
> The second one (which is more r6rs-alike) looks less verbose, isn't
> it?
> Can anyone please tell me why the first one is preferred, thank you
> very much!

The first one is preferred because it cleanly separates the declarative
library language from the actual Scheme code.  What if you have an
`export' or an `import' function in your own code?  (You could get
around it by wrapping them in a `begin' (or another such "escape") each
time you want to use them in the top-level of your own code, but that
would be very dirty, obviously if you ask me.)

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