This page is part of the web mail archives of SRFI 26 from before July 7th, 2015. The new archives for SRFI 26 contain all messages, not just those from before July 7th, 2015.
It seems to me that the symmetric lisp1 nature of scheme, in which the evaluation of the operator and operand positions of a procedure call are identical, calls for cut to allow any of its arguments to be slots: (map (cut <> 7) (list + - (cut - <> 2))) => (7 -7 5) (define (run-thunks) (for-each (cut <>) the-thunks)) (define (run-hooks hooks arg) (for-each (cut <> arg) hooks)) To effect this change in the BNF spec, change <proc> <const-or-slot>* to <const-or-slot>+. Here's a macro that implements this change, plus one-time argument evaluation, and allows consts after the rest-slot: (define-syntax cut (syntax-rules () ((_ . cut-args) (letrec-syntax ((find-end ;; Reverse the expressions/slots until we find the end or ;; the rest-slot. (syntax-rules (<...>) ((_ rev) (p #f () () () () . rev)) ((_ rev <...>) (p #t () () x (x) . rev)) ((_ rev <...> . exps) (p #t y exps x ((append x y)) . rev)) ((_ rev exp . exps) (find-end (exp . rev) . exps)))) (p ;; p: process the expressions/slots after they have been reversed. ;; When finished, form an outer lambda that saves the ;; expression results, and an inner lambda that invokes a ;; combination, using apply if necessary. ;; Called as: (p need-apply? temps orig-exps slot-names combination ;; expression-or-slot ...) (syntax-rules (<>) ((_ a t o s c <> . es) (p a t o (x . s) (x . c) . es)) ((_ a t o s c e . es) (p a (y . t) (e . o) s (y . c) . es)) ((_ #t t o s c) ((lambda t (lambda s (apply . c))) . o)) ((_ #f t o s c) ((lambda t (lambda s c)) . o))))) (find-end () . cut-args))))) -al