diff options
Diffstat (limited to 'object.c')
-rw-r--r-- | object.c | 39 |
1 files changed, 29 insertions, 10 deletions
@@ -2221,20 +2221,39 @@ rb_mod_const_set(VALUE mod, VALUE name, VALUE value) * mod.const_defined?(sym, inherit=true) -> true or false * mod.const_defined?(str, inherit=true) -> true or false * - * Checks for a constant with the given name in <i>mod</i> - * If +inherit+ is set, the lookup will also search - * the ancestors (and +Object+ if <i>mod</i> is a +Module+.) + * Says whether _mod_ or its ancestors have a constant with the given name: * - * Returns whether or not a definition is found: + * Float.const_defined?(:EPSILON) #=> true, found in Float itself + * Float.const_defined?("String") #=> true, found in Object (ancestor) + * BasicObject.const_defined?(:Hash) #=> false * - * Math.const_defined? "PI" #=> true - * IO.const_defined? :SYNC #=> true - * IO.const_defined? :SYNC, false #=> false + * If _mod_ is a +Module+, additionally +Object+ and its ancestors are checked: * - * If neither +sym+ nor +str+ is not a valid constant name a NameError will be - * raised with a warning "wrong constant name". + * Math.const_defined?(:String) #=> true, found in Object + * + * In each of the checked classes or modules, if the constant is not present + * but there is an autoload for it, +true+ is returned directly without + * autoloading: + * + * module Admin + * autoload :User, 'admin/user' + * end + * Admin.const_defined?(:User) #=> true + * + * If the constant is not found the callback +const_missing+ is *not* called + * and the method returns +false+. + * + * If +inherit+ is false, the lookup only checks the constants in the receiver: + * + * IO.const_defined?(:SYNC) #=> true, found in File::Constants (ancestor) + * IO.const_defined?(:SYNC, false) #=> false, not found in IO itself + * + * In this case, the same logic for autoloading applies. + * + * If the argument is not a valid constant name +NameError+ is raised with the + * message "wrong constant name _name_": * - * Hash.const_defined? 'foobar' #=> NameError: wrong constant name foobar + * Hash.const_defined? 'foobar' #=> NameError: wrong constant name foobar * */ |