New Lisp functions ASSOC, EFFACE, MAPLIST

resources/mexpr/assoc.mexpr.lsp

@@ -0,0 +1,7 @@
+;; Not present in Lisp 1.5(!)
+
+assoc[x; l] = [null[l] -> NIL;
+            and[consp[car[l]]; eq[caar[l]; x]] -> cdar[l];
+            T -> assoc[x; cdr[l]]]
+
+;; (ASSOC 'C (PAIR '(A B C D E F) (RANGE 1 6)))

resources/mexpr/efface.mexpr.lsp

@@ -0,0 +1,6 @@
+;; page 63. I'm not at all sure why an implementation using RPLACD is preferred
+;; over a pure functional implementation here.
+
+efface[x; l] = [null[l] -> NIL; 
+            equal[x; car[l]] -> cdr[l];
+            T -> rplacd[l; efface[x; cdr[l]]]]

resources/mexpr/maplist.mexpr.lsp

@@ -0,0 +1,4 @@
+;; page 63
+
+maplist[l; f] = [null[l] -> nil;
+                T -> cons[f[car[l]]; maplist[cdr[l]; f]]]