Author: autrijus
Date: Tue May 2 10:46:43 2006
New Revision: 9103
Modified:
doc/trunk/design/syn/S02.pod
Log:
* S02: Clarify that subscripts evaluates under list context
at RHS, but scalar context at LHS. Also adds some
example code to illustrate various interactions.
Modified: doc/trunk/design/syn/S02.pod
==============================================================================
--- doc/trunk/design/syn/S02.pod (original)
+++ doc/trunk/design/syn/S02.pod Tue May 2 10:46:43 2006
@@ -12,9 +12,9 @@
Maintainer: Larry Wall <[EMAIL PROTECTED]>
Date: 10 Aug 2004
- Last Modified: 1 May 2006
+ Last Modified: 2 May 2006
Number: 2
- Version: 36
+ Version: 37
This document summarizes Apocalypse 2, which covers small-scale
lexical items and typological issues. (These Synopses also contain
@@ -589,10 +589,21 @@
=item *
The context in which a subscript is evaluated is no longer controlled
-by the sigil either. Subscripts are always evaluated in list context
-on the assumption that slicing behavior is desired. If you need to
-force inner context to scalar, we now have convenient single-character
-context specifiers such as + for numbers and ~ for strings.
+by the sigil either. Subscripts are always evaluated in scalar context
+when used as a lvalue, and list context when used as a rvalue.
+
+If you need to force inner context to scalar, we now have convenient
+single-character context specifiers such as + for numbers and ~ for strings.
+Conversely, put parenthesis around the lvalue expression to force inner
+context to list:
+
+ @x[f()] = g(); # scalar context for f() and g()
+ @x[f()] = @y[g()]; # scalar context for f(), list context for g()
+ @x[f()] = @y[+g()]; # scalar context for f() and g()
+
+ (@x[f()]) = g(); # list context for f() and g()
+ (@x[f()]) = @y[g()]; # list context for f() and g()
+ (@x[f()]) = @y[+g()]; # list context for f(), scalar context for g()
=item *
