8 Oct
2006
8 Oct
'06
20:16
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 8-Oct-06, at 6:35 PM, Aycan iRiCAN wrote:
Hi,
What is the meaning of '=> symbol used in cond forms?
Best Regards,
In Scheme the form (cond (X => F) ...) is equivalent to (let ((x X)) (if x (F x) (cond ...))) This is useful when the result of the test (the expression X) is needed in the clause selected. This is frequently used in code like (cond ((assoc X Y) => cdr) ...) Marc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (Darwin) iD8DBQFFKZTx//V9Zc2T/v4RAiDxAJ4hIuljNHsGFIcVFr/I6cxr8CHmwgCfc1w8 s4rxaA/zU54hxeNXGbNpml4= =B/Uz -----END PGP SIGNATURE-----