The Inbox: Kernel-ul.1059.mcz

Levente Uzonyi uploaded a new version of Kernel to project The Inbox:
http://source.squeak.org/inbox/Kernel-ul.1059.mcz

==================== Summary ====================

Name: Kernel-ul.1059
Author: ul
Time: 11 February 2017, 3:00:22.370854 am
UUID: b88b767b-b0d8-43ff-ba86-a19b11affe6d
Ancestors: Kernel-ul.1058

- check the type of the argument of #& and #| of booleans

=============== Diff against Kernel-ul.1058 ===============

Item was changed:
  ----- Method: False>>& (in category 'logical operations') -----
  & aBoolean
+ "Evaluating conjunction -- answer false since receiver is false, but let the VM quickly check the type of the argument first."
- "Evaluating conjunction -- answer false since receiver is false."
 
+ aBoolean ifFalse: [ ^false ].
+ ^false!
- ^self!

Item was changed:
  ----- Method: False>>| (in category 'logical operations') -----
  | aBoolean
+ "Evaluating disjunction (OR) -- could  answer aBoolean since receiver is false, but let the VM quickly check the type of the argument instead."
- "Evaluating disjunction (OR) -- answer with the argument, aBoolean."
 
+ aBoolean ifTrue: [ ^true ].
+ ^false!
- ^aBoolean!

Item was changed:
  ----- Method: True>>& (in category 'logical operations') -----
  & aBoolean
+ "Evaluating conjunction -- could answer aBoolean since receiver is true, but let the VM quickly check the type of the argument instead."
- "Evaluating conjunction -- answer aBoolean since receiver is true."
 
+ aBoolean ifFalse: [ ^false ].
+ ^true!
- ^aBoolean!

Item was changed:
  ----- Method: True>>| (in category 'logical operations') -----
  | aBoolean
+ "Evaluating disjunction (OR) -- answer true since the receiver is true, but let the VM quickly check the type of the argument first."
- "Evaluating disjunction (OR) -- answer true since the receiver is true."
 
+ aBoolean ifTrue: [ ^true ].
+ ^true!
- ^self!

Hi Levente

On 11.02.2017, at 03:04, [hidden email] wrote:

Why do we want the check?
I see no advantage…

Best regards
        -Tobias

Hi Tobias,

On Sat, 11 Feb 2017, Tobias Pape wrote:
Not too long ago there was this thread[1] with the following kind of
example:

a = b | c = d ifTrue: [ ... ].

The type check will quickly let you know if you forget a pair of
parentheses:

a = b | (c = d) ifTrue: [ ... ].

The runtime is about 1.5-2x compared to the original methods, but if you
use #| and #&, you probably don't care about performance anyway.

Levente

[1] http://forum.world.st/I-was-surprised-td4928576.html

On 11.02.2017, at 11:11, Levente Uzonyi <[hidden email]> wrote:

Sure.
I however liked the simplicity of the old methods :/