pair.rb in nydp-0.4.5

- old
+ new

@@ -14,21 +14,32 @@
   def cadr       ; cdr.car                                    ; end
   def cdar       ; car.cdr                                    ; end
   def cddr       ; cdr.cdr                                    ; end
   def car= thing ; @car = thing ; @_hash = nil                ; end
   def cdr= thing ; @cdr = thing ; @_hash = nil                ; end
-  def hash       ; @_hash ||= (car.hash + cdr.hash)           ; end
+  # def hash       ; @_hash ||= (car.hash + cdr.hash)           ; end
+  def hash       ; (car.hash + cdr.hash)                      ; end # can't cache hash of symbol, breaks when unmarshalling
   def eql? other ; self == other                              ; end
   def copy       ; cons(car, cdr.copy)                        ; end
   def +    other ; copy.append other                          ; end
   def size       ; 1 + (cdr.is_a?(Nydp::Pair) ? cdr.size : 0) ; end
   def inspect    ; "(#{inspect_rest})"                        ; end
   def &    other ; self.class.from_list((Set.new(self) & other).to_a)           ; end
   def |    other ; self.class.from_list((Set.new(self) | other).to_a)           ; end
   def -    other ; self.class.from_list((Set.new(self) - other).to_a)           ; end
   def proper?    ; Nydp::NIL.is?(cdr) || (cdr.is_a?(Nydp::Pair) && cdr.proper?) ; end
 
+  def index_of x
+    if x == car
+      0
+    elsif pair?(cdr)
+      1 + cdr.index_of(x)
+    else
+      nil
+    end
+  end
+
   # returns Array of elements after calling #n2r on each element
   def to_ruby list=[]
     list << n2r(car)
     cdr.is_a?(Nydp::Pair) ? cdr.to_ruby(list) : list
   end
@@ -49,10 +60,10 @@
 
   def self.from_list list, last=Nydp::NIL, n=0
     if n >= list.size
       last
     else
-      new list[n], from_list(list, last, n+1)
+      Nydp::Pair.new list[n], from_list(list, last, n+1)
     end
   end
 
   def == other
     (NIL != other) && (other.respond_to? :car) && (self.car == other.car) && (self.cdr == other.cdr)