Add a diff library.

I was hesitant to add a diff library, but it was surprisingly easy. A
straightforward application of dynamic programming.

1 files changed, 1 insertions, 47 deletions

diff --git a/csc/ir2.csc b/csc/ir2.csc
index 462a4a4..7ab2803 100644
--- a/csc/ir2.csc
+++ b/csc/ir2.csc
@@ -27,7 +27,6 @@
     fix-body
     fix-functions
     fix?
-    ir2=?
     kargs-expression
     kargs-refs
     kargs?
@@ -72,7 +71,6 @@
   (import (scheme base)
           (only (csc ir1)
             constant?
-            ir1=?
             lexical-ref-gensym
             lexical-ref-name
             lexical-ref?
@@ -183,48 +181,4 @@
       fix?
       %fix
       (functions fix-functions)
-      (body fix-body))
-
-
-    (define (atom=? x y)
-      (if (and (variable? x) (variable? y))
-        #t
-        (ir1=? x y)))
-
-
-    (define (closure=? x y)
-      (and (closure? x) (closure? y)
-        (let ((x-args (closure-arguments x))
-              (x-rest (closure-rest x))
-              (y-args (closure-arguments y))
-              (y-rest (closure-rest y)))
-          (and (atom=? (closure-name x) (closure-name y))
-               (= (length x-args) (length y-args))
-               (all atom=? x-args y-args)
-               (or (and (not x-rest) (not y-rest))
-                   (and x-rest y-rest (atom=? x-rest y-rest)))
-               (ir2=? (closure-body x) (closure-body y))))))
-
-
-    (define (ir2=? x y)
-      (match (cons x y)
-        (((% %primitive x-oper x-args x-res x-cont) . (% %primitive y-oper y-args y-res y-cont))
-          (and (symbol=? x-oper y-oper)
-               (= (length x-args) (length y-args))
-               (all atom=? x-args y-args)
-               (= (length x-res) (length y-res))
-               (all atom=? x-res y-res)
-               (ir2=? x-cont y-cont)))
-        (((% %branch x-atom x-true x-false) . (% %branch y-atom y-true y-false))
-          (and (atom=? x-atom y-atom)
-               (ir2=? x-true y-true)
-               (ir2=? x-false y-false)))
-        (((% %apply x-proc x-args) . (% %apply y-proc y-args))
-          (and (atom=? x-proc y-proc)
-               (= (length x-args) (length y-args))
-               (all atom=? x-args y-args)))
-        (((% %fix x-funs x-body) . (% %fix y-funs y-body))
-          (and (= (length x-funs) (length y-funs))
-               (all closure=? x-funs y-funs)
-               (ir2=? x-body y-body)))
-        (_ #f)))))
+      (body fix-body))))