From 5847a6b0548b3c99056a867fa053015dfe3754a5 Mon Sep 17 00:00:00 2001
From: Kyle <kyle@tyrfingr.is>
Date: Wed, 2 Sep 2015 00:12:42 -0700
Subject: [PATCH] Add with-gensyms and in macros.

---
 docs/manual.scr | 16 ++++++++++++++--
 macros.lisp     | 29 +++++++++++++++++++++++++++++
 on.lisp         |  9 +++++++++
 package.lisp    |  2 ++
 4 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/docs/manual.scr b/docs/manual.scr
index a6ec979..d39232b 100644
--- a/docs/manual.scr
+++ b/docs/manual.scr
@@ -87,6 +87,7 @@ some functions I found useful.)
 @cl:doc(function group)
 @cl:doc(function flatten)
 @cl:doc(function compose)
+@cl:doc(macro with-gensyms)
 )
 
 
@@ -263,10 +264,13 @@ Evaluate @c(body), and call @c(mkstr) on the result. Write the
 resulting string to @c(path). Any remaining arguments are sent to
 @c(with-open-file).
 
-
-
 @end(def)
 
+@term(General)
+
+@cl:with-package[name="kutils"](
+@cl:doc(macro in))
+
 @end(deflist)
 
 @end(section)
@@ -373,6 +377,9 @@ utilities".)
 @item(@c(iflet*) is a macro defined in @c(macros.lisp), described in
 "Macros" under "Let macros".)
 
+@item(@c(in) is a macro defined in @c(macros.lisp), described in
+"Macros" under "General".)
+
 @item(@c(interpose) is a function defined in @c(kutils.lisp),
 described in "Miscellaneous utilities" under "Clojure-inspired
 functions".)
@@ -433,6 +440,9 @@ Lisp utilities".)
 @item(@c(whenlet*) is a macro defined in @c(macros.lisp), described in
 "Macros" under "Let macros".)
 
+@item(@c(with-gensyms) is a macro defined in @c(on.lisp), described in
+"On Lisp utilities".)
+
 @item(@c(with-new-hash-table) is a macro defined in
 @c(kutils-hash-tables.lisp), described in "Hash-table related
 utilities".)
@@ -480,6 +490,7 @@ Alphabetical documentation for all exported symbols.
 @cl:doc(function hashkeys)
 @cl:doc(macro iflet)
 @cl:doc(macro iflet*)
+@cl:doc(macro in)
 @cl:doc(function interpose)
 @cl:doc(function macroexpand-n)
 @cl:doc(macro mapv)
@@ -497,6 +508,7 @@ Alphabetical documentation for all exported symbols.
 @cl:doc(macro unlesslet*)
 @cl:doc(macro whenlet)
 @cl:doc(macro whenlet*)
+@cl:doc(macro with-gensyms)
 @cl:doc(macro with-new-hash-table)
 @cl:doc(macro with-read-from-file)
 @cl:doc(macro with-write-to-file)
diff --git a/macros.lisp b/macros.lisp
index 3de880e..4e6acbb 100644
--- a/macros.lisp
+++ b/macros.lisp
@@ -113,3 +113,32 @@ value of @c(stream). Any remaining keyword arguments are passed to
     (error "Specifying :direction is not allowed with WRITE-FILE."))
   `(with-open-file (,stream ,path :direction ,direction ,@args)
      ,@body))
+
+(defun is (a b test key)
+  "Are a and b equal? If not NIL, #'key is applied to b, then #'test
+is called on both."
+  (declare (inline))
+  (funcall test
+           (if key
+               (funcall key b)
+             b)
+           a))
+
+(defmacro in (obj seq &key (test #'eql) key deep)
+  "Returns T if @c(obj), which may be a vector or list), is in
+@c(seq); using @c(test) to determine whether the object matches. If
+@c(key) is not NIL, it is applied to the key before @c(test). If
+@c(deep) is true, @c(seq) will be flattened before checking the
+list. Note that @c(deep) is only valid for lists, and will not behave
+as expected with vectors."
+  (with-gensyms (obj% seq% x!)
+    (declare (dynamic-extent obj% seq% x!))
+    `(let ((,obj% ,obj)
+	   (,seq% (if ,deep ,(flatten seq) ,seq)))
+       (cond
+	 ((vectorp ,seq%)
+	  (loop for ,x! across ,seq%
+	     thereis (is ,obj% ,x! ,test ,key)))
+	 ((listp ,seq%)
+	  (loop for ,x! in ,seq%
+	     thereis (is ,obj% ,x! ,test ,key)))))))
diff --git a/on.lisp b/on.lisp
index b8fd97d..3a52fa5 100644
--- a/on.lisp
+++ b/on.lisp
@@ -53,3 +53,12 @@ composed together in a chain."
                         :from-end t
                         :initial-value (apply fn1 args))))
           #'identity))
+
+(defmacro with-gensyms (syms &body body)
+  "Binds a whole list of variables to gensyms."
+  `(let ,(mapcar #'(lambda (s)
+                     `(,s (gensym)))
+                 syms)
+     ,@body))
+
+
diff --git a/package.lisp b/package.lisp
index 2b754a8..ae7e8ac 100644
--- a/package.lisp
+++ b/package.lisp
@@ -8,6 +8,7 @@
            #:group
            #:flatten
            #:compose
+	   #:with-gensyms
 
 	   ;; lol.lisp : utilities from Let Over Lambda
            #:defmacro!
@@ -55,4 +56,5 @@
 	   #:with-string-output-to-file
 	   #:with-read-from-file
 	   #:with-write-to-file
+	   #:in
            ))