On Sat, 2006-09-09 at 11:17 +0100, Jón Fairbairn wrote: . . .
I should think so. But does lisp have currying these days? (lessp 0 1) ==> T but (lessp 0) would be an error, wouldn't it?
For Scheme, R5RS, Section 6.2.5 specifies that "<" and ">" take two or more arguments, and PLT Scheme raises an exception on "(< 0)". For Common Lisp, CLtL2 specifies for =, /=, <. >, <=, >= that "These functions take one or more arguments" (p. 293). "(< x1 ...)" is true when the arguments form a monotonically increasing sequence, and clearly a singleton sequence is monotonic. In the CLISP implementation of Common Lisp "(< 0)" returns "T". BTW there is no "lessp" in CL. As you noted, CL and Scheme do not support currying. However, SRFI 16 (Scheme Request for Implementation, a quasi-standard mechanism for introducing extension libraries into Scheme) provides a "Notation for Specializing Parameters without Currying" as a syntactic sugar for nested lambdas. -- Bill Wood