Add flip and orlet.

docs/flip.lisp

@@ -0,0 +1,5 @@
+CL-USER> (format t "(- 7 3) -> ~A~%"
+		 (funcall (flip #'- 3) 7))
+(- 7 3) -> 4
+NIL
+

docs/manual.scr

@@ -117,6 +117,8 @@ some functions I found useful.)
 @code(@include[path=examples.lisp start=1 end=5]())
 @cl:doc(function effector)
 @cl:doc(function empty-or-nil-p)
+@cl:doc(function flip)
+@code(@include[path="flip.lisp"]())
 @cl:doc(function macroexpand-n)
 @cl:doc(function mksymb)
 @cl:doc(function mkkw)
@@ -224,6 +226,8 @@ For example, from @c(kmop/kmop.lisp):
 @cl:doc(macro condlet*)
 @cl:doc(macro iflet)
 @cl:doc(macro iflet*)
+@cl:doc(macro orlet)
+@code(@include[path="orlet.lisp"]())
 @cl:doc(macro unlesslet)
 @cl:doc(macro unlesslet*)
 @cl:doc(macro whenlet)
@@ -360,6 +364,9 @@ described in "Miscellaneous utilities" under "Vector-related".)
 @item(@c(flatten) is a function defined in @c(on.lisp), described in
 "On Lisp utilities".)
 
+@item(@c(flip) is a function defined in @c(kutils.lisp), described in
+"Miscellaneous utilities" under "General".)
+
 @item(@c(group) is a function defined in @c(kutils.lisp), described in
 "On Lisp utilities".)
 
@@ -410,6 +417,9 @@ utilities".)
 @item(@c(new-vector) is a function defined in @c(kutils.lisp),
 described in "Miscellaneous utilities" under "Vector-related".)
 
+@item(@c(orlet) is a macro defined in @c(macros.lisp), described in
+"Macros" under "Let macros".)
+
 @item(@c(partial) is a function defined in @c(kutils.lisp), described
 in "Miscellaneous utilities" under "Clojure-inspired functions".)
 
@@ -485,6 +495,7 @@ Alphabetical documentation for all exported symbols.
 @cl:doc(function enable-hash-table-reader)
 @cl:doc(function extend-vector)
 @cl:doc(function flatten)
+@cl:doc(function flip)
 @cl:doc(function group)
 @cl:doc(function hash-table-to-alist)
 @cl:doc(function hashkeys)
@@ -499,6 +510,7 @@ Alphabetical documentation for all exported symbols.
 @cl:doc(function mksymb)
 @cl:doc(function new-hash-table)
 @cl:doc(function new-vector)
+@cl:doc(macro orlet)
 @cl:doc(function partial)
 @cl:doc(function partition)
 @cl:doc(macro sethash)

docs/orlet.lisp

@@ -0,0 +1,12 @@
+(macroexpand-1
+	  '(orlet ((cls  (class-symbol s))
+		   (slots (only-key-slots cls))
+		   (args (json-slots tbl slots)))
+	    (apply #'make-instance cls args)))
+(LET ((CLD (CLASS-SYMBOL S)))
+  (WHEN CLS
+    (LET ((SLOTS (ONLY-KEY-SLOTS CLS)))
+      (WHEN SLOTS
+	(LET ((ARGS (JSON-SLOTS TBL SLOTS)))
+	  (WHEN ARGS
+	    (PROGN (APPLY #'MAKE-INSTANCE CLS ARGS))))))))

kutils.lisp

@@ -46,6 +46,11 @@ additional args provided to the lambda."
   (lambda (&rest args)
     (apply fn (append initial-args args))))
 
+(defun flip (fn y)
+  "Given a function @c(fn) that takes arguments @c(x) and @c(y), return a lambda with @c(y) applied to the function."
+  (lambda (x)
+    (funcall fn x y)))
+
 (defun macroexpand-n (n form)
   "Expand the macro n times."
   (let ((new-form form))

macros.lisp

@@ -4,6 +4,17 @@
 
 ;;; Various utility macros.
 
+(defun orletfun (bindings finally)
+  (if (null bindings)
+      finally
+      `(let (,(first bindings))
+	 (when ,(first (first bindings))
+	   ,(orletfun (rest bindings) finally)))))
+
+(defmacro orlet (bindings &body body)
+  "For each set of bindings, evaluate them in sequence. If each binding evaluates to T, evaluate @c(body) in a @c(progn)."  
+  (orletfun bindings `(progn ,@body)))
+
 (defmacro whenlet (bindings &body body)
   "Evaluate the bindings in a let form; if they all evaluate to T,
 evaluate @c(body) in an implicit @c(progn)."

package.lisp

@@ -19,6 +19,7 @@
 	   #:drop
            #:build-list
            #:partial
+	   #:flip
            #:macroexpand-n
            #:mksymb
            #:mkkw
@@ -44,6 +45,7 @@
            #:alist-to-hash-table
 
 	   ;; macros.lisp
+	   #:orlet
 	   #:whenlet
 	   #:whenlet*
 	   #:unlesslet