Properly vivify nonexistent glob slots

[perl/modules/Scope-Upper.git] / lib / Scope / Upper.pm

diff --git a/lib/Scope/Upper.pm b/lib/Scope/Upper.pm
index 91219ff91e5b7fcd63cf1027d022412d35bce5d1..84de02eea6ebf8befe98320881ff7d27f3d421fa 100644 (file)
--- a/lib/Scope/Upper.pm
+++ b/lib/Scope/Upper.pm
@@ -162,6 +162,10 @@ For example,
 
 will localize C<$Tool::tag> and not C<$Scope::tag>.
 
+Note that if C<$what> is a string denoting a variable that wasn't declared beforehand, the relevant slot will be vivified as needed and won't be deleted from the glob when the localization ends.
+This situation never arises with C<local> because it only compiles when the localized variable is already declared.
+Although I believe it shouldn't be a problem as glob slots definedness is pretty much an implementation detail, this behaviour may change in the future if proved harmful.
+
 =back
 
 =head2 C<localize_elem $what, $key, $value, $context>
@@ -170,6 +174,8 @@ Similar to L</localize> but for array and hash elements.
 If C<$what> is a glob, the slot to fill is determined from which type of reference C<$value> is ; otherwise it's inferred from the sigil.
 C<$key> is either an array index or a hash key, depending of which kind of variable you localize.
 
+Just like for L</localize>, when C<$what> is a string pointing to an undeclared variable, it will be vivified but the variable itself will be empty when the localization ends (although it will still exist in its parent glob).
+
 =head2 C<localize_delete $what, $key, $context>
 
 Similiar to L</localize>, but for deleting variables or array/hash elements.