First draft of the regex engine

rxwork.pl

@@ -0,0 +1,45 @@
+my class Cursor {
+    # has $!str
+    # has $!from
+    method str() { $!str }
+    method from() { $!from }
+}
+
+sub _rxstar($¢, $sub) {
+}
+
+sub _rxlazymap($cs, $sub) {
+    my class LazyIterator is Iterator {
+        # $!valid $!value $!next  $!fun $!back
+        method validate() {
+            $!valid = 1;
+            my $f = $!fun;
+            if ! $!back.valid {
+                $!back.validate;
+            }
+            my $bv = $!back.value;
+            my $bn = $!back.next;
+            # XXX horrible. we're making the value act @-ish, maybe
+            Q:CgOp {
+                (prog
+                  (setindex value (getfield slots (cast DynObject (@ (l self))))
+                    (callsub (@ (l $f)) (l $bv)))
+                  (null Variable))
+            };
+            $!next = LazyIterator.RAWCREATE("valid", 0, "next", Any,
+                "value", Any, "back", $nb, "fun", $!fun);
+        }
+    }
+
+    List.RAWCREATE("flat", 1, "items", LLArray.new(), "rest",
+        LLArray.new(LazyIterator.new("valid", 0, "value", Any, "next", Any,
+            "back", $cs.iterator, "fun", $fun)));
+}
+
+sub _rxstr($¢, $str) {
+}
+
+# regex { a b* c }
+sub rxtest($¢) {
+    _rxlazymap(_rxstr($¢, 'a'), sub ($¢) { _rxlazymap(_rxstar($¢, sub ($¢) { _rxstr($¢, 'b') }), sub ($¢) { _rxstr($¢, 'c') }) })
+}