From 3062b939f20b857f13e282fe143290033d1e7958 Mon Sep 17 00:00:00 2001
From: "Samuel W. Flint" <swflint@flintfam.org>
Date: Sun, 23 Oct 2016 11:20:44 -0500
Subject: [PATCH] Brought in aget and ensure-list because informatimago is no
 longer in quicklisp

---
 larcs.org | 68 ++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 60 insertions(+), 8 deletions(-)

diff --git a/larcs.org b/larcs.org
index 22b85cb41c5ddeec3b0de88a99ff0a86b4543eb1..fc1ca173d511ce541ff0cf343ec5c3cf19166889 100644
--- a/larcs.org
+++ b/larcs.org
@@ -85,7 +85,7 @@ The CAS contained in this is called LARCS, or the Lisp Automated Rewrite and Cal
 #+TOC: headlines 3
 #+TOC: listings
 
-* DONE Common Functionality [3/3]
+* WORKING Common Functionality [3/5]
 :PROPERTIES:
 :CREATED:  <2016-06-11 Sat 22:23>
 :ID:       f153a0fe-ec04-47b1-bdc5-290cc62bc985
@@ -173,6 +173,58 @@ This is a mapping between the names of constants and the way that they are corre
   (mapcar #'export *constant-names*)
 #+END_SRC
 
+** TODO Aget
+:PROPERTIES:
+:CREATED:  <2016-10-23 Sun 11:14>
+:END:
+
+#+Caption: Aget
+#+Name: common-aget
+#+BEGIN_SRC lisp
+  (defun aget (place indicator &optional default)
+    "
+  RETURN:   The value of the entry INDICATOR of the a-list PLACE, or DEFAULT.
+  "
+    (let ((a (assoc indicator place)))
+      (if a (cdr a) default)))
+
+  (define-setf-expander aget (place indicator &optional default &environment env)
+    (declare (ignore default))
+    (multiple-value-bind (vars vals store-vars writer-form reader-form)
+        (get-setf-expansion place env)
+      (let* ((vindicator (gensym "INDICATOR"))
+             (vvalue     (gensym "VALUE"))
+             (vstore     (first store-vars))
+             (acs        (gensym "PAIR")))
+        (values (list* vindicator vars)
+                (list* indicator  vals)
+                (list  vvalue)
+                `(let* ((,acs (assoc ,vindicator ,reader-form)))
+                   (if ,acs
+                       (setf (cdr ,acs) ,vvalue)
+                       (let ((,vstore (acons ,vindicator ,vvalue ,reader-form)))
+                         ,writer-form))
+                   ,vvalue)
+                `(assoc ,vindicator ,reader-form)))))
+#+END_SRC
+
+** TODO Ensure List
+:PROPERTIES:
+:CREATED:  <2016-10-23 Sun 11:17>
+:ID:       08d8e031-a30f-41b6-9981-caec2f07f2a0
+:END:
+
+#+Caption: Ensure List
+#+Name: ensure-list
+#+BEGIN_SRC lisp
+  (defun ensure-list (object)
+    "
+  RETURN:         If OBJECT is a list then OBJECT, otherwise a fresh
+                  list containing OBJECT.
+  "
+    (if (listp object) object (list object)))
+#+END_SRC
+
 ** DONE Assembly
 CLOSED: [2016-07-30 Sat 15:43]
 :PROPERTIES:
@@ -190,6 +242,10 @@ This is where the common functions and constants are assembled into their own pa
   <<common-generate-an-args-list>>
 
   <<constants-and-greeks>>
+
+  <<aget>>
+
+  <<ensure-list>>
 #+END_SRC
 
 * DONE Expression Typing [8/8]
@@ -2379,7 +2435,9 @@ This defines the common package, which keeps a few macros and variables that are
                   #:symbolicate)
     (:export #:gen-args-list
              #:*special-symbols-to-sequences*
-             #:*constant-names*)
+             #:*constant-names*
+             #:aget
+             #:ensure-list)
     (:nicknames #:common))
 #+END_SRC
 
@@ -2478,9 +2536,6 @@ This is a rather simple package, providing a way to differentiate equations for
           #:larcs.polynomials)
     (:import-from #:alexandria
                   #:symbolicate)
-    (:import-from #:com.informatimago.common-lisp.cesarum.list
-                  #:aget
-                  #:ensure-list)
     (:export :differentiate)
     (:nicknames :diff))
 #+END_SRC
@@ -2505,9 +2560,6 @@ Again, this is a relatively simple package definition, providing a way to conver
           #:larcs.polynomials)
     (:import-from #:alexandria
                   #:symbolicate)
-    (:import-from #:com.informatimago.common-lisp.cesarum.list
-                  #:aget
-                  #:ensure-list)
     (:export #:convert-for-display)
     (:nicknames #:typeset))
 #+END_SRC