[Python-Dev] list splicing

Mon Sep 19 03:50:14 CEST 2005

Hi, has anybody considered adding something like this:
 a = [1, 2]
 [ 'x', *a, 'y']
as syntactic sugar for
 a = [1, 2]
 [ 'x' ] + a + [ 'y' ].
Notes:
- This is a common operation
- To me, the splicing form looks much better than the
 concatenation form
- It can be implemented more efficiently than a bunch of list
 concatenations
- This would be similar to the "apply" feature [ foo(*a) ]. The
 '*' operator is reminiscent of dereferencing operators in
 C-derived languages. Alternatively it could be '@', like perl's
 implicit array splicing, and Lisp's ',@' in backquoted lists.
- (I know "splicing" traditionally refers to something else in
 Python, but other languages refer to this as splicing, and the
 English definition of "splice" applies better to this.)
-- 
Karl 2005年09月18日 18:26