Talk:Eiffel Breaking Changes - Revision history

Alexander Kogtenkov: Cosmetics.

2016-01-22T16:21:12Z

Cosmetics.

← Older revision		Revision as of 16:21, 22 January 2016
Line 1:		Line 1:
	==Void-safe copy==		==Void-safe copy==
	[[User:Alexander Kogtenkov\|Alexander Kogtenkov]] ([[User talk:Alexander Kogtenkov\|talk]]) 08:20, 22 January 2016 (PST)		'''[[User:Alexander Kogtenkov\|Alexander Kogtenkov]] ([[User talk:Alexander Kogtenkov\|talk]]) 08:21, 22 January 2016 (PST)'''

	Possible approaches:		Possible approaches:
	{\| class="wikitable" border="1" style="border-collapse:collapse; border-color: LightGrey;"		{\| class="wikitable" border="1" style="border-collapse:collapse; border-color: LightGrey;"

Alexander Kogtenkov at 16:20, 22 January 2016

2016-01-22T16:20:24Z

← Older revision		Revision as of 16:20, 22 January 2016
Line 1:		Line 1:
	~~[[User:Alexander Kogtenkov\|Alexander Kogtenkov]] ([[User talk:Alexander Kogtenkov\|talk]]) 08:19, 22 January 2016 (PST)~~
	==Void-safe copy==		==Void-safe copy==
			[[User:Alexander Kogtenkov\|Alexander Kogtenkov]] ([[User talk:Alexander Kogtenkov\|talk]]) 08:20, 22 January 2016 (PST)
	Possible approaches:		Possible approaches:
	{\| class="wikitable" border="1" style="border-collapse:collapse; border-color: LightGrey;"		{\| class="wikitable" border="1" style="border-collapse:collapse; border-color: LightGrey;"

Alexander Kogtenkov: Started a discussion on void safe copy.

2016-01-22T16:19:52Z

Started a discussion on void safe copy.

New page

[[User:Alexander Kogtenkov|Alexander Kogtenkov]] ([[User talk:Alexander Kogtenkov|talk]]) 08:19, 22 January 2016 (PST)
==Void-safe copy==
Possible approaches:
{| class="wikitable" border="1" style="border-collapse:collapse; border-color: LightGrey;"
|- style="vertical-align: top;"
! scope="col"| Solution
! scope="col"| Rules for expanded classes
! scope="col"| Pros
! scope="col"| Cons
|- style="vertical-align: top;"
| Remove <e>clone</e> altogether and make <e>copy</e> a creation procedure where needed.
| <e>copy</e> is a mandatory creation procedure for expanded classes. Then reattachment to an expanded entity means creation of an expanded object with regular creation rules.
|
* No magic.
* No special run-time support.
|
* Partial code duplication for every class (<e>Precursor</e> can be used to reduce duplication).
|- style="vertical-align: top;"
| Remove <e>copy</e> altogether. Add a class <e>CLONEABLE</e> with a deferred feature <e>twin</e>.
| Expanded classes should inherit <e>CLONEABLE</e> (and define <e>twin</e>).
|
* No magic.
|
* Code duplication for every class.
|-
|}
Special rules for expanded classes can be removed altogether. Instead additional requirements will be added:
* reattachment with a source of an expanded type is valid only if ...
* actual generic of an expanded class is valid only if ...
* changing a type in a declaration from reference to expanded is valid only if ...
where ... is as specified in the '''Rules for expanded classes''' above. This would allow to have expanded classes that cannot be copied and this may be useful in some scenarios.