Easy question about syntax.
I have a simple one, but i need to understand what is going on.. i have something like Tree with a class method trees ^ trees ifNil: [OrderedCollection new] i initially ran into trouble with it locking my image up because i wrote it as: trees ^ self trees ifNil: [OrderedCollection new] what is the semantic difference between these two calls? THanks!  ---- peace, sergio photographer, journalist, visionary Public Key: http://bit.ly/29z9fG0 #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV http://www.Village-Buzz.com http://www.ThoseOptimizeGuys.com http://www.coffee-black.com http://www.painlessfrugality.com http://www.twitter.com/sergio_101 http://www.facebook.com/sergio101
i think that in the first case you access an instance variable trees while in the second case you send a message trees to self that cause an infinite recursion. am i right? On Sat, Mar 11, 2017 at 12:57 AM, sergio ruiz <sergio.rrd@gmail.com> wrote:
I have a simple one, but i need to understand what is going on..
i have something like
Tree
with a class method
trees ^ trees ifNil: [OrderedCollection new]
i initially ran into trouble with it locking my image up because i wrote it as:
trees ^ self trees ifNil: [OrderedCollection new]
what is the semantic difference between these two calls?
THanks!
---- peace, sergio photographer, journalist, visionary
Public Key: http://bit.ly/29z9fG0 #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV http://www.Village-Buzz.com http://www.ThoseOptimizeGuys.com http://www.coffee-black.com http://www.painlessfrugality.com http://www.twitter.com/sergio_101 http://www.facebook.com/sergio101
-- Bernardo E.C. Sent from a cheap desktop computer in South America.
Also, youâre not setting the instance variable - just returning an OrderedCollection - is that what you want to do? e.g. setting the trees instance variable: trees ^ trees ifNil: [ trees := OrderedCollection new ] like Bernardo said, when you call #trees from within the #trees method (with self trees) - like in your first example, you created an infinite loop.
On 11 Mar 2017, at 3:36 pm, Bernardo Ezequiel Contreras <vonbecmann@gmail.com> wrote:
i think that in the first case you access an instance variable trees while in the second case you send a message trees to self that cause an infinite recursion. am i right?
On Sat, Mar 11, 2017 at 12:57 AM, sergio ruiz <sergio.rrd@gmail.com <mailto:sergio.rrd@gmail.com>> wrote: I have a simple one, but i need to understand what is going on..
i have something like
Tree
with a class method
trees ^ trees ifNil: [OrderedCollection new]
i initially ran into trouble with it locking my image up because i wrote it as:
trees ^ self trees ifNil: [OrderedCollection new]
what is the semantic difference between these two calls?
THanks!
---- peace, sergio photographer, journalist, visionary
Public Key: http://bit.ly/29z9fG0 <http://bit.ly/29z9fG0> #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV http://www.Village-Buzz.com <http://www.village-buzz.com/> http://www.ThoseOptimizeGuys.com <http://www.thoseoptimizeguys.com/> http://www.coffee-black.com <http://www.coffee-black.com/> http://www.painlessfrugality.com <http://www.painlessfrugality.com/> http://www.twitter.com/sergio_101 <http://www.twitter.com/sergio_101> http://www.facebook.com/sergio101 <http://www.facebook.com/sergio101>
-- Bernardo E.C.
Sent from a cheap desktop computer in South America.
Am 11.03.2017 um 04:57 schrieb sergio ruiz <sergio.rrd@gmail.com>:
I have a simple one, but i need to understand what is going on..
i have something like
Tree
with a class method
trees ^ trees ifNil: [OrderedCollection new]
i initially ran into trouble with it locking my image up because i wrote it as:
trees ^ self trees ifNil: [OrderedCollection new]
what is the semantic difference between these two calls?
The first one accesses the instance variable. The second one calls the method tress (same method) which results in an endless loop. Norbert
THanks!
---- peace, sergio photographer, journalist, visionary
Public Key: http://bit.ly/29z9fG0 #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV http://www.Village-Buzz.com http://www.ThoseOptimizeGuys.com http://www.coffee-black.com http://www.painlessfrugality.com http://www.twitter.com/sergio_101 http://www.facebook.com/sergio101
participants (4)
-
Bernardo Ezequiel Contreras -
Jupiter Jones -
Norbert Hartl -
sergio ruiz