Author: larry Date: Fri Feb 16 18:29:45 2007 New Revision: 13589 Modified: doc/trunk/design/syn/S06.pod
Log: Clarification on what may be returned from, requested by rhr++ Modified: doc/trunk/design/syn/S06.pod ============================================================================== --- doc/trunk/design/syn/S06.pod (original) +++ doc/trunk/design/syn/S06.pod Fri Feb 16 18:29:45 2007 @@ -13,9 +13,9 @@ Maintainer: Larry Wall <[EMAIL PROTECTED]> Date: 21 Mar 2003 - Last Modified: 12 Feb 2007 + Last Modified: 16 Feb 2007 Number: 6 - Version: 70 + Version: 71 This document summarizes Apocalypse 6, which covers subroutines and the @@ -1732,15 +1732,23 @@ =head2 The C<leave> function As mentioned above, a C<return> call causes the innermost surrounding -subroutine, method, rule, token, regex (as a keyword) or macro to -return. Only declarations with an explicit keyword such as "sub" -may be returned from. You may not use C<return> to return from loops, -bare blocks, pointy blocks, or quotelike operators such as C<rx//>. - -To return from these types of code structures, the C<leave> method -is used instead. (It can be taken to mean either "go away from" or -"bequeath to your successor" as appropriate.) -The object specifies the scope to exit, +subroutine, method, rule, token, regex (as a keyword) or macro +to return. Only declarations with an explicit declarator keyword +(C<sub>, C<submethod>, C<method>, C<macro>, C<regex>, C<token>, and +C<rule>) may be returned from. Statement prefixes such a C<do> and +C<try> do not fall into that category. You may not use C<return> to +return from loops, bare blocks, pointy blocks, or quotelike operators +such as C<rx//>; a C<return> within one of those constructs will +continue searching outward for a "proper" routine to return from. +Nor may you return from property blocks such as C<BEGIN> or C<CATCH> +(though blocks executing within the lexical and dynamic scope of a +routine can of course return from that outer routine, which means +you can always return from a C<CATCH> or a C<FIRST>, but never from +a C<BEGIN> or C<INIT>.) + +To return from blocks that aren't routines, the C<leave> method is used +instead. (It can be taken to mean either "go away from" or "bequeath +to your successor" as appropriate.) The object specifies the scope to exit, and the method's arguments specify the return value. If the object is omitted (by use of the function or listop forms), the innermost block is exited. Otherwise you must use something like C<caller>
