Tree-native byte processing

lib/bytes.tri

@@ -0,0 +1,49 @@
+!import "base.tri" !Local
+!import "list.tri" !Local
+
+nothing = t
+just = x : t x
+
+bytesIsNil = emptyList?
+
+bytesHead = matchList nothing (h _ : just h)
+
+bytesTail = matchList nothing (_ r : just r)
+
+byteEq = equal?
+bytesLength = length
+bytesAppend = append
+
+bytesTake_ = y (self n i remaining :
+  matchBool
+    t
+    (matchList
+      t
+      (h r : pair h (self n (succ i) r))
+      remaining)
+    (equal? i n))
+
+bytesTake = n bytes : bytesTake_ n 0 bytes
+
+bytesDrop_ = y (self n i remaining :
+  matchBool
+    remaining
+    (matchList
+      t
+      (_ r : self n (succ i) r)
+      remaining)
+    (equal? i n))
+
+bytesDrop = n bytes : bytesDrop_ n 0 bytes
+
+bytesSplitAt = n bytes : pair (bytesTake n bytes) (bytesDrop n bytes)
+
+bytesEq = y (self xs ys :
+  matchList
+    (matchList true (_ _ : false) ys)
+    (xh xt :
+      matchList
+        false
+        (yh yt : and? (byteEq xh yh) (self xt yt))
+        ys)
+    xs)