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[xtend2] filter() and class selection [message #758681]

Thu, 24 November 2011 08:33

Klaus Birken

Messages: 4
Registered: November 2011

Junior Member

Hi,

I started using Xtend2 for transformation and generation recently, it is a great and elegant language!

However, I guess I didn't understand all language concepts so far. The following question arises: In order to select all elements from a list which are instances of a certain class I am using this code:

var List<MyBaseClass> all = ...
all.filter(m | m instanceof SomeClass).map(m | m as SomeClass)

The filter selects the elements, but returns a Iterable<MyBaseClass>. The map() casts this to Iterable<SomeClass>, which is what I want to have.

---

I guess there might be a shorter way to do this... reading the online doc I think

all.filter(SomeClass)

should work. But it doesn't ("Couldn't resolve reference to JvmIdentifiableElement 'SomeClass'.").

What do I get wrong here?

Thanks in advance, regards,
Klaus

[Updated on: Thu, 24 November 2011 08:35]

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Re: [xtend2] filter() and class selection [message #758682 is a reply to message #758681]

Thu, 24 November 2011 08:38

Meinte Boersma

Messages: 434
Registered: July 2009
Location: Leiden, Netherlands

Senior Member

all.filter(typeof(SomeClass))

Xtext blogs: executable models...again? | workshop material | custom scoping with Xtend

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Re: [xtend2] filter() and class selection [message #758683 is a reply to message #758681]

Thu, 24 November 2011 08:38

Christian Dietrich

Messages: 14665
Registered: July 2009

Senior Member

all.filter(typeof(SomeClass))

Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

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Re: [xtend2] filter() and class selection [message #758685 is a reply to message #758683]

Thu, 24 November 2011 09:04

Klaus Birken

Messages: 4
Registered: November 2011

Junior Member

Thanks to both of you, it works. Actually, I found it in the xtend reference, at least now Smile

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Re: [xtend2] filter() and class selection [message #758686 is a reply to message #758685]

Thu, 24 November 2011 09:16

Meinte Boersma

Messages: 434
Registered: July 2009
Location: Leiden, Netherlands

Senior Member

Good, you're actually reading the reference and it took you less than 5 hours! Smile

(This is actually about another thread Wink

)

Xtext blogs: executable models...again? | workshop material | custom scoping with Xtend

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