State of ifEmpty:ifNotEmpty:, ifNil:ifNotNil: and related messages across Smalltalks?

Question

What is the current state of messages like ifEmpty:ifNotEmpty:, ifEmpty:, ifNotEmpty: ifNil:ifNotNil:, ifNil: and ifNotNil:?

Are they available across Smalltalks, and do they behave consistently? You still see things like "object isEmpty ifTrue: [...] ifFalse: [...]" in older code.

Answer 1

Currently, I think the state of the art is covered very well by the Seaside coding convetions:

Portability

[…]

Do not use any of these methods, they are missing, broken or have different semantics on some platforms:

[…]

• Object: #ifNotNil:, #ifNotNilDo:, #in:, ...
• Boolean: #and:and:and:, #or:or:or:, ...
• Collection: #=, #pairsDo:, #with:collect:
• String: #match:
• Stream: #position, #position:, #isEmpty

[…]

(highlighting by yours truly)

Since Seaside has been ported to Pharo, Squeak, GemStone, Dolphin, VisualWorks, VA Smalltalk, GNU Smalltalk, I think this list has some authority.

Also note that even #isEmpty seems to be not portable, for Streams at least.