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Bug 368220

Summary:	[Xbase] elvis "operator"
Product:	[Modeling] TMF	Reporter:	Sven Efftinge <sven.efftinge>
Component:	Xtext	Assignee:	Project Inbox <tmf.xtext-inbox>
Status:	CLOSED FIXED	QA Contact:
Severity:	enhancement
Priority:	P3	CC:	mckinley1411, sebastian.zarnekow
Version:	2.3.0	Flags:	sebastian.zarnekow: juno+
Target Milestone:	Final
Hardware:	PC
OS:	Mac OS X - Carbon (unsup.)
Whiteboard:

Description Sven Efftinge

2012-01-10 03:03:51 EST

The elvis operator effectively allows to provide a default value in case an expression evaluates to 'null'.

Example :

  someStringOrNull :? 'hello'

I propose to do this via library using an extension method on java.lang.Object.

  someStringOrNull.ifnull['hello']

@rrmckinley suggested via twitter to use a shorter more readable name like 'or' or 'else'. 
Unfortunately 'else' being a keyword won't work and 'or' could be surprising since as it would be defined on Object the following expression would result in 'false':

false.or[true]

Any other suggestions?

Comment 1 McKinley

2012-01-10 03:14:31 EST

I agree with you that 'or' is a bad surprise. I rescind! ;-) Null should be in the method name to be the best guide.

Comment 2 Sebastian Zarnekow

2012-01-10 04:24:47 EST

I find ifNull the most intuitive name. IMO 'else' or 'or' are not descriptive enough and I don't think that we really need a shorter name than ifNull.

Comment 3 Sebastian Zarnekow

2012-07-05 04:56:34 EDT

Available in 2.3

Comment 4 Eclipse Webmaster

2017-10-31 10:48:16 EDT

Requested via bug 522520.

-M.

Comment 5 Eclipse Webmaster

2017-10-31 10:59:16 EDT

Requested via bug 522520.

-M.