--- This message is a formal comment which was submitted to [EMAIL PROTECTED], following the requirements described at: http://www.r6rs.org/process.html --- name: Kent Dybvig email: [EMAIL PROTECTED] type: enhancement priority: minor component: base or lists library version: 5.92
Summary: add list* or cons* Description: The list* procedure (aka. cons*) provided by Common Lisp and some Scheme systems is like list but puts its last argument in the cdr of the final pair. If only one argument is supplied, it returns that argument. It does not accept zero arguments. For example: (list* 1 2 '(3 4 5)) ;=> (1 2 3 4 5) (list* 1 2 3) ;=> (1 2 . 3) (list* 1) ;=> 1 In my experience this is a handy procedure to have at the user level and is the list-processing procedure I use most often outside of those already contained in the report. It's also useful in the expansion of quasiquote to produce more readable code than the equivalent sets of nested conses, and may be useful in other, user-written code-construction macros. It's also less work for an implementation to generate efficient code for list* than for the equivalent set of nested conses. The name cons* used by MIT Scheme and possibly others is probably more descriptive than the name list*, but the name list* is probably compatible with a larger body of code. Proposal: Add either list* or cons*. _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
