From 057af65f5e6d6bf6a31ec5484ac23a7ce845157d Mon Sep 17 00:00:00 2001
From: Colin Okay <cbeok@protonmail.com>
Date: Thu, 30 Jul 2020 08:48:13 -0500
Subject: added anaphoric FOLD and FOR

---
 anaphora.lisp | 26 ++++++++++++++++++++++++++
 gtwiwtg.asd   |  3 ++-
 gtwiwtg.lisp  |  1 -
 package.lisp  |  7 +++++++
 4 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 anaphora.lisp

diff --git a/anaphora.lisp b/anaphora.lisp
new file mode 100644
index 0000000..13bb980
--- /dev/null
+++ b/anaphora.lisp
@@ -0,0 +1,26 @@
+(in-package #:gtwiwtg.anaphora)
+
+(defmacro afor (generator &body body)
+  "Anaphoric FOR. Binds the values produced by GENERATOR to the variable IT.
+
+Example: 
+
+> (afor (times 3) (print it))
+0
+1
+2
+
+"
+  `(for it ,expr ,@body))
+
+(defmacro afold (init generator update)
+  "Anaphoric FOLD. Binds the values produced by GENERATOR to IT, and
+binds the accumulating variable to ACC.
+
+Example:
+
+> (afold 0 (times 10) (+ acc it))
+45
+
+"
+  `(fold (acc ,init) (it ,expr) ,update))
diff --git a/gtwiwtg.asd b/gtwiwtg.asd
index d30b7cb..d412cdc 100644
--- a/gtwiwtg.asd
+++ b/gtwiwtg.asd
@@ -7,5 +7,6 @@
   :version "0.1.1"
   :serial t
   :components ((:file "package")
-               (:file "gtwiwtg"))
+               (:file "gtwiwtg")
+               (:file "anaphora"))
   :in-order-to ((test-op (test-op gtwiwtg-test))))
diff --git a/gtwiwtg.lisp b/gtwiwtg.lisp
index 6f0f6f3..f1a5038 100644
--- a/gtwiwtg.lisp
+++ b/gtwiwtg.lisp
@@ -1,4 +1,3 @@
-(defpackage #:gtwiwtg (:use #:cl))
 (in-package :gtwiwtg)
 
 ;;; Generator Protocol ;;;
diff --git a/package.lisp b/package.lisp
index 061ddb7..848146d 100644
--- a/package.lisp
+++ b/package.lisp
@@ -42,3 +42,10 @@
            #:average
            #:argmax
            #:argmin))
+
+(defpackage #:gtwiwtg.anaphora
+  (:use #:cl)
+  (:import-from #:gtwiwtg
+                #:for
+                #:fold)
+  (:export #:afor #:afold #:it #:acc))
-- 
cgit v1.2.3