Replace left(), right(), and __reversed__() with the more general purpose

__getitem__() and __setitem__().

Simplifies the API, reduces the code size, adds flexibility, and makes
deques work with bisect.bisect(), random.shuffle(), and random.sample().

1 files changed, 6 insertions, 15 deletions

diff --git a/Doc/lib/libcollections.tex b/Doc/lib/libcollections.tex
index 2793095..14e3bf5 100644
--- a/Doc/lib/libcollections.tex
+++ b/Doc/lib/libcollections.tex
@@ -54,11 +54,6 @@ Deque objects support the following methods:
    reversing the order of elements in the iterable argument.
 \end{methoddesc}
 
-\begin{methoddesc}{left}{}
-   Return leftmost element from the deque.
-   If no elements are present, raises a \exception{IndexError}.   
-\end{methoddesc}
-
 \begin{methoddesc}{pop}{}
    Remove and return an element from the right side of the deque.
    If no elements are present, raises a \exception{IndexError}.
@@ -69,11 +64,6 @@ Deque objects support the following methods:
    If no elements are present, raises a \exception{IndexError}.   
 \end{methoddesc}
 
-\begin{methoddesc}{right}{}
-   Return the rightmost element from the deque.
-   If no elements are present, raises a \exception{IndexError}.   
-\end{methoddesc}
-
 \begin{methoddesc}{rotate}{n}
    Rotate the deque \var{n} steps to the right.  If \var{n} is
    negative, rotate to the left.  Rotating one step to the right
@@ -81,8 +71,9 @@ Deque objects support the following methods:
 \end{methoddesc}
 
 In addition to the above, deques support iteration, pickling, \samp{len(d)},
-\samp{reversed(d)}, \samp{copy.copy(d)}, \samp{copy.deepcopy(d)}, and
-membership testing with the \keyword{in} operator.
+\samp{reversed(d)}, \samp{copy.copy(d)}, \samp{copy.deepcopy(d)},
+membership testing with the \keyword{in} operator, and subscript references
+such as \samp{d[-1]}.
 
 Example:
 
@@ -106,11 +97,11 @@ deque(['f', 'g', 'h', 'i', 'j'])
 'f'
 >>> list(d)                          # list the contents of the deque
 ['g', 'h', 'i']
-
->>> d.left()                         # peek at leftmost item
+>>> d[0]                             # peek at leftmost item
 'g'
->>> d.right()                        # peek at rightmost item
+>>> d[-1]                            # peek at rightmost item
 'i'
+
 >>> list(reversed(d))                # list the contents of a deque in reverse
 ['i', 'h', 'g']
 >>> 'h' in d                         # search the deque