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How to iterate through a HashMap in Xtend? [message #792949]

Tue, 07 February 2012 15:45

Soenke Brightside

Messages: 41
Registered: January 2011

Member

Hi,

As the title says: How can i iterate through a Hashmap in Xtend?

Sönke

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Re: How to iterate through a HashMap in Xtend? [message #792995 is a reply to message #792949]

Tue, 07 February 2012 16:42

Sebastian Zarnekow

Messages: 3118
Registered: July 2009

Senior Member

Am 07.02.12 16:45, schrieb Soenke Escher:
> Hi,
>
> As the title says: How can i iterate through a Hashmap in Xtend?
>
> Sönke

Sönke,

for(e: map.entrySet) {
..
}

should do the trick.

Alternatively you could use

map.forEach [key, value | ..]

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com

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Re: How to iterate through a HashMap in Xtend? [message #793585 is a reply to message #792995]

Wed, 08 February 2012 10:09

Soenke Brightside

Messages: 41
Registered: January 2011

Member

Thank you Sebastian,

i already tryed this but the problem is the e/key/value has the type Object and i cannot cast them to Map.Entry.

"Couldn't resolve reference to JvmType 'Map.Entry'."

Sönke

[Updated on: Wed, 08 February 2012 10:11]

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Re: How to iterate through a HashMap in Xtend? [message #793595 is a reply to message #793585]

Wed, 08 February 2012 10:24

Sebastian Zarnekow

Messages: 3118
Registered: July 2009

Senior Member

Sönke,

how's your map defined / instantiated?

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com

Am 08.02.12 11:09, schrieb Soenke Escher:
> Thank you Sebastian,
>
> i already tryed this but the problem is the e/key/value has the type
> Object and i cannot cast them to Map.Entry.
>
> Sönke
>
>

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Re: How to iterate through a HashMap in Xtend? [message #793596 is a reply to message #793595]

Wed, 08 February 2012 10:28

Soenke Brightside

Messages: 41
Registered: January 2011

Member

Hi,

var hmap = new HashMap<SystemComponent, List<SystemComponent>>();

Sönke

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Re: How to iterate through a HashMap in Xtend? [message #793609 is a reply to message #793596]

Wed, 08 February 2012 10:43

Sebastian Zarnekow

Messages: 3118
Registered: July 2009

Senior Member

Sönke,

this works for me:

import java.util.HashMap
import java.util.List

class X {
def forLoopMap() {
var hmap = new HashMap<String, List<String>>();
for(e: hmap.entrySet) {
val String key = e.key
val String firstValue = e.value.head
// to avoid unused variable warnings
if (key == firstValue)
return
}
}

def forEachMap() {
var hmap = new HashMap<String, List<String>>();
hmap.forEach [ k, v |
val String key = k
val String firstValue = v.head
// to avoid unused variable warnings
if (key == firstValue)
return
]
}
}

Which version of Xtend do you use?

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com

Am 08.02.12 11:28, schrieb Soenke Escher:
> Hi,
>
> var hmap = new HashMap<SystemComponent, List<SystemComponent>>();
>
> Sönke

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Re: How to iterate through a HashMap in Xtend? [message #793617 is a reply to message #793609]

Wed, 08 February 2012 10:55

Soenke Brightside

Messages: 41
Registered: January 2011

Member

Hi,

I use Xtend2 2.2.1. Your code runs fine.

Here a code-snippet of mine:

def dispatch compile(ProjectRepository pr, IFileSystemAccess fsa) {
for(e:pr.hashMap.entrySet){
// e is type of object. cant do anything with it.
}
}

def HashMap getHashMap(ProjectRepository pr){
var hmap = new HashMap<SystemComponent, List<SystemComponent>>();
//do something
return hmap;
}

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Re: How to iterate through a HashMap in Xtend? [message #793620 is a reply to message #793617]

Wed, 08 February 2012 10:58

Soenke Brightside

Messages: 41
Registered: January 2011

Member

Got it. I had to change

def HashMap getHashMap(ProjectRepository pr){
to
def HashMap<SystemComponent, List<SystemComponent>> getHashMap(ProjectRepository pr){

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