@@ 0,0 1,75 @@ 
+;; Composable predicates
+
+(define-module (composable-predicates)
+  #:use-module ((srfi srfi-1) #:select (fold))
+  #:export (compose-pred))
+
+(define (compose-pred pred . preds)
+  (define (chain-it proc chain)
+    (lambda (arg)
+      (if (proc arg)
+	  (chain arg)
+	  #f)))
+  (fold chain-it pred preds))
+
+  
+
+(define-syntax define-with-arg-return
+  (syntax-rules ()
+    ((_ (name orig) ...)
+     (begin
+       (define (name arg)
+	 (and (orig arg) arg))
+       ...
+       (export! (name . orig) ...)))))
+
+
+(define-with-arg-return
+  ;; chars
+  (cchar? char?)
+  (cchar-alphabetic? char-alphabetic?)
+  (cchar-is-both?    char-is-both?)
+  (cchar-lower-case? char-lower-case?)
+  (cchar-numeric?    char-numeric?)
+  (cchar-upper-case? char-upper-case?)
+  (cchar-whitespace? char-whitespace?)
+
+  ;; lists and pairs
+  (llist? list?)
+  (nnull? null?)
+  (ppair? pair?)
+
+  ;; numerics
+  (ccomplex?       complex?)
+  (eeven?          even?)
+  (eexact?         exact?)
+  (eexact-integer? exact-integer?)
+  (iinexact?       inexact?)
+  (iinf?           inf?)
+  (iinteger?       integer?)
+  (nnegative?      negative?)
+  (nnumber?        number?)
+  (oodd?           odd?)
+  (ppositive?      positive?)
+  (rrational?      rational?)
+  (rreal?          real?)
+  (zzero?          zero?)
+
+  ;; ports
+  (iinput-port? input-port?)
+  (pport? port?)
+  (ooutput-port? output-port?)
+  (ttextual-port? textual-port?)
+
+  ;; String
+  (sstring? string?)
+  (sstring-null? string-null?)
+
+  ;; symbols
+  (ssymbol-interned? symbol-interned?)
+  (ssymbol?          symbol?)
+
+  (ssyntax? syntax?)
+  (vvector? vector?)
+
+  )