General Scala question

Hi Andreas,

Welcome to Scala!

On the Scala vs. Groovy thing, Scala (like Java) is a statically typed
language. From experience, when a project exceeds some medium
complexity, then static typing helps a great deal understanding what
is going on with the desing&behaviour. It also helps reasoning about
the program. I have written such medium-sized programs in Python (and
many years ago in Perl) and I reached a point of missing every detail
of a static type system. Not to mention that you tend to get better
performance with static typing. Furthermore, and as personal thought,
I believe static typing helps us dive deeper into *the very essence of
programming*.

On the Scala vs Java thing, well Scala is far more expressive than
Java. It has richer abstractions that help code our ideas using less
boilerplate. It also brings some new ideas (new at least to the
hardcore Java programmers) on how to declare and combine behaviour.

Scala's core is object-functional, meaning that Scala has succeeded in
marrying two complementary programming philosophies: object-oriented
and functional programming. Given the fact that OOP has traditionally
been used to model complex system and FP really shines in a bottom-up
approach where you combine/compose little things to get something
bigger, then just imagine what can be done with this combination that
Scala promotes.

Do not be worried if this all seems too much. You can start playing
with Scala (which I thing is a far better teaching language than Java)
and discover your way as you go on. The Scala site provides a wealth
of info and the lists are here to help/discuss!

On the car/highway issue, Groovy and Java absolutely do not share the
same car but they are moving in some adjacent highway. Scala is
already flying above.

BR
Christos

On Jun 16, 2009, at 2:00 PM, Andreas Jöcker wrote:

> Hi all,
>
> I just started to discover Scala and out of curiosity I try to
> understand what is unique in scala or in what ways it is
> better/simpler/more intuitive to use.
>
> I'm coming from the Java corner and during the last weeks I learned
> about Groovy and all its features.
>
> When I first encountered Scala I was surprised by the different syntax
> but thats just a question of using it.
>
> My essentiell problem for understanding is - what is unique / special
> about scala.
>
> First I thought it has the same ideas than groovy, but apparently the
> even the concepts are different.
>
> Dirk Koenig, a groovianer, wrote once (talking about conceptionally
> differences of Java / Scala and Groovy)
>
>> Groovy and Java share the same car.
>> Scala is driving on the same highway.
>
> Would you agree and the most important question:
>
> What car are you driving ?
>
> Cheers
> A
>
> PS: I'm trying to find the place for Scala in my language world -
> hopefully you can help me here ;-)
>

Hello Andreas,

first welcome to Scala!. I also learned Groovy before moving to Scala. I think Groovy is also a powerful language sharing many features with Scala, but one big difference for me is the static typing of Scala (a very important language feature for large, mission critical projects), in Groovy it is only optional and if you use it you lose much of the power. In Scala it is not the case, you have the power despite of static typing. This is one of the great innovations in Scala, I think. Another point is Scala's performance, which is similar to Java and better suited for multi-core systems.

I think I get the sense of Dirk Koenigs statement, I didn't heard before, Groovy uses the same type system as Java and "extends" the syntax, they are very close to each other. Scala is a little apart but still running in the JVM (the highway).

I hope, this helps you a little. Surely you will get other comments from the community.

Viel Spaß mit Scala!
Antonio R. Rodríguez Santiesteban.

2009/6/16 Andreas Jöcker <a.joecker@gis-systemhaus.de>

Hi all,

I just started to discover Scala and out of curiosity I try to
understand what is unique in scala or in what ways it is
better/simpler/more intuitive to use.

I'm coming from the Java corner and during the last weeks I learned
about Groovy and all its features.

When I first encountered Scala I was surprised by the different syntax
but thats just a question of using it.

My essentiell problem for understanding is - what is unique / special
about scala.

First I thought it has the same ideas than groovy, but apparently the
even the concepts are different.

Dirk Koenig, a groovianer, wrote once (talking about conceptionally
differences of Java / Scala and Groovy)

> Groovy and Java share the same car.
> Scala is driving on the same highway.

Would you agree and the most important question:

What car are you driving ?

Cheers
A

PS: I'm trying to find the place for Scala in my language world -
hopefully you can help me here ;-)

--

Andreas Jöcker
GiS - Gesellschaft für integrierte Systemplanung mbH
Junkersstr. 2
69469 Weinheim

E-Mail   a.joecker@gis-systemhaus.de
Telefon +49 6201 503-59
Fax     +49 6201 503-66

Gesellschaft für integrierte Systemplanung mbH
Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435

--
Dr. Antonio R. Rodríguez Santiesteban
Java-Plattform-Entwickler

Tel.: (030) 74921026
Priv. Tel.: (030) 470 03 470
Mobil: 01577 2856 033
E-Mail: rodant68@googlemail.com

Thanks all for these informative comments.

I have to admit from what I was reading I though static typing in Scala
is also optional, with some exceptions (e.g. recursive methods). And as
in Groovy you can omit the type as this will be inferred.
Or do we talk beyond the source code ?

One thing which is appealing to me about Groovy is the whole
infrastructure of frameworks (Grails for web, Griffon for desktop, gant
for ant or gradle for kind of maven) - are there similiar projects in
Scala ?

Othwerwise - thanks for the comments - i will try to dig deeper into Scala

Cheers
A

On Tue, Jun 16, 2009 at 1:00 PM, Andreas Jöcker <a.joecker@gis-systemhaus.de> wrote:

Hi all,

I just started to discover Scala and out of curiosity I try to
understand what is unique in scala or in what ways it is
better/simpler/more intuitive to use.

I'm coming from the Java corner and during the last weeks I learned
about Groovy and all its features.

When I first encountered Scala I was surprised by the different syntax
but thats just a question of using it.

My essentiell problem for understanding is - what is unique / special
about scala.

First I thought it has the same ideas than groovy, but apparently the
even the concepts are different.

Dirk Koenig, a groovianer, wrote once (talking about conceptionally
differences of Java / Scala and Groovy)

> Groovy and Java share the same car.
> Scala is driving on the same highway.

...but Scala's in the fast-lane... ;)
 

Would you agree and the most important question:

What car are you driving ?

Cheers
A

PS: I'm trying to find the place for Scala in my language world -
hopefully you can help me here ;-)

--

Andreas Jöcker
GiS - Gesellschaft für integrierte Systemplanung mbH
Junkersstr. 2
69469 Weinheim

E-Mail   a.joecker@gis-systemhaus.de
Telefon +49 6201 503-59
Fax     +49 6201 503-66

Gesellschaft für integrierte Systemplanung mbH
Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435

--
Viktor Klang
Scala Loudmouth

Andreas, static typing is "always on" in Scala. You can omit the type in many situations, where the it is clear from the context and the compiler can figure it out, type inference. If you leave the type in Groovy out, you have no static type checking at this artifact.

For Scala there is the Lift web framework, an interesting approach for web development and as in Groovy, all Java frameworks are available. An Scala DSL for Ant is for me unknown. Pinky is also an Scala web framework that I remember, but maybe not as mature as Lift.

Cheers.

2009/6/16 Andreas Jöcker <a.joecker@gis-systemhaus.de>

Thanks all for these informative comments.

I have to admit from what I was reading I though static typing in Scala
is also optional, with some exceptions (e.g. recursive methods). And as
in Groovy you can omit the type as this will be inferred.
Or do we talk beyond the source code ?

One thing which is appealing to me about Groovy is the whole
infrastructure of frameworks (Grails for web, Griffon for desktop, gant
for ant or gradle for kind of maven) - are there similiar projects in
Scala ?

Othwerwise - thanks for the comments - i will try to dig deeper into Scala

Cheers


--

Andreas Jöcker
GiS - Gesellschaft für integrierte Systemplanung mbH
Junkersstr. 2
69469 Weinheim

E-Mail   a.joecker@gis-systemhaus.de
Telefon +49 6201 503-59
Fax     +49 6201 503-66

Gesellschaft für integrierte Systemplanung mbH
Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435

--
Dr. Antonio R. Rodríguez Santiesteban
Java-Plattform-Entwickler

Tel.: (030) 74921026
Priv. Tel.: (030) 470 03 470
Mobil: 01577 2856 033
E-Mail: rodant68@googlemail.com

Hi Andreas, static typing and type annotating are different things. What
Groovy calls static typing is actually not static typing -- it is type
annotating. Scala has static typing and optional type annotating.

Andreas Jöcker wrote:
> Thanks all for these informative comments.
>
> I have to admit from what I was reading I though static typing in Scala
> is also optional, with some exceptions (e.g. recursive methods). And as
> in Groovy you can omit the type as this will be inferred.
> Or do we talk beyond the source code ?
>
> One thing which is appealing to me about Groovy is the whole
> infrastructure of frameworks (Grails for web, Griffon for desktop, gant
> for ant or gradle for kind of maven) - are there similiar projects in
> Scala ?
>
> Othwerwise - thanks for the comments - i will try to dig deeper into Scala
>
> Cheers
> A
>
>

Groovy's static typing is not optional, but non-existent.

int x = "hello"; is valid Groovy. It compiles, but throws an
exception. That's not static typing, but a syntax for runtime
assertions.

2009/6/16 Antonio Rodríguez S. :
> Hello Andreas,
>
> first welcome to Scala!. I also learned Groovy before moving to Scala. I
> think Groovy is also a powerful language sharing many features with Scala,
> but one big difference for me is the static typing of Scala (a very
> important language feature for large, mission critical projects), in Groovy
> it is only optional and if you use it you lose much of the power. In Scala
> it is not the case, you have the power despite of static typing. This is one
> of the great innovations in Scala, I think. Another point is Scala's
> performance, which is similar to Java and better suited for multi-core
> systems.
>
> I think I get the sense of Dirk Koenigs statement, I didn't heard before,
> Groovy uses the same type system as Java and "extends" the syntax, they are
> very close to each other. Scala is a little apart but still running in the
> JVM (the highway).
>
> I hope, this helps you a little. Surely you will get other comments from the
> community.
>
> Viel Spaß mit Scala!
> Antonio R. Rodríguez Santiesteban.
>
> 2009/6/16 Andreas Jöcker
>>
>> Hi all,
>>
>> I just started to discover Scala and out of curiosity I try to
>> understand what is unique in scala or in what ways it is
>> better/simpler/more intuitive to use.
>>
>> I'm coming from the Java corner and during the last weeks I learned
>> about Groovy and all its features.
>>
>> When I first encountered Scala I was surprised by the different syntax
>> but thats just a question of using it.
>>
>> My essentiell problem for understanding is - what is unique / special
>> about scala.
>>
>> First I thought it has the same ideas than groovy, but apparently the
>> even the concepts are different.
>>
>> Dirk Koenig, a groovianer, wrote once (talking about conceptionally
>> differences of Java / Scala and Groovy)
>>
>> > Groovy and Java share the same car.
>> > Scala is driving on the same highway.
>>
>> Would you agree and the most important question:
>>
>> What car are you driving ?
>>
>> Cheers
>> A
>>
>> PS: I'm trying to find the place for Scala in my language world -
>> hopefully you can help me here ;-)
>>
>> --
>>
>> Andreas Jöcker
>> GiS - Gesellschaft für integrierte Systemplanung mbH
>> Junkersstr. 2
>> 69469 Weinheim
>>
>> E-Mail   a.joecker@gis-systemhaus.de
>> Telefon +49 6201 503-59
>> Fax     +49 6201 503-66
>>
>> Gesellschaft für integrierte Systemplanung mbH
>> Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
>> Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
>> Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435
>>
>
>
>
> --
> Dr. Antonio R. Rodríguez Santiesteban
> Java-Plattform-Entwickler
>
> Tel.: (030) 74921026
> Priv. Tel.: (030) 470 03 470
> Mobil: 01577 2856 033
> E-Mail: rodant68@googlemail.com
>

If I got it right, it was a year ago, if you use the Groovy compiler you should get a compilation error for int x = "hello". If you use the interpreter otherwise, a ClassCastException should occur.

Cheers.

2009/6/16 Ricky Clarkson <ricky.clarkson@gmail.com>

Groovy's static typing is not optional, but non-existent.

int x = "hello"; is valid Groovy.  It compiles, but throws an
exception.  That's not static typing, but a syntax for runtime
assertions.

2009/6/16 Antonio Rodríguez S. <rodant68@googlemail.com>:
> Hello Andreas,
>
> first welcome to Scala!. I also learned Groovy before moving to Scala. I
> think Groovy is also a powerful language sharing many features with Scala,
> but one big difference for me is the static typing of Scala (a very
> important language feature for large, mission critical projects), in Groovy
> it is only optional and if you use it you lose much of the power. In Scala
> it is not the case, you have the power despite of static typing. This is one
> of the great innovations in Scala, I think. Another point is Scala's
> performance, which is similar to Java and better suited for multi-core
> systems.
>
> I think I get the sense of Dirk Koenigs statement, I didn't heard before,
> Groovy uses the same type system as Java and "extends" the syntax, they are
> very close to each other. Scala is a little apart but still running in the
> JVM (the highway).
>
> I hope, this helps you a little. Surely you will get other comments from the
> community.
>
> Viel Spaß mit Scala!
> Antonio R. Rodríguez Santiesteban.
>
> 2009/6/16 Andreas Jöcker <a.joecker@gis-systemhaus.de>
>>
>> Hi all,
>>
>> I just started to discover Scala and out of curiosity I try to
>> understand what is unique in scala or in what ways it is
>> better/simpler/more intuitive to use.
>>
>> I'm coming from the Java corner and during the last weeks I learned
>> about Groovy and all its features.
>>
>> When I first encountered Scala I was surprised by the different syntax
>> but thats just a question of using it.
>>
>> My essentiell problem for understanding is - what is unique / special
>> about scala.
>>
>> First I thought it has the same ideas than groovy, but apparently the
>> even the concepts are different.
>>
>> Dirk Koenig, a groovianer, wrote once (talking about conceptionally
>> differences of Java / Scala and Groovy)
>>
>> > Groovy and Java share the same car.
>> > Scala is driving on the same highway.
>>
>> Would you agree and the most important question:
>>
>> What car are you driving ?
>>
>> Cheers
>> A
>>
>> PS: I'm trying to find the place for Scala in my language world -
>> hopefully you can help me here ;-)
>>
>> --
>>
>> Andreas Jöcker
>> GiS - Gesellschaft für integrierte Systemplanung mbH
>> Junkersstr. 2
>> 69469 Weinheim
>>
>> E-Mail   a.joecker@gis-systemhaus.de
>> Telefon +49 6201 503-59
>> Fax     +49 6201 503-66
>>
>> Gesellschaft für integrierte Systemplanung mbH
>> Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
>> Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
>> Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435
>>
>
>
>
> --
> Dr. Antonio R. Rodríguez Santiesteban
> Java-Plattform-Entwickler
>
> Tel.: (030) 74921026
> Priv. Tel.: (030) 470 03 470
> Mobil: 01577 2856 033
> E-Mail: rodant68@googlemail.com
>

--
Dr. Antonio R. Rodríguez Santiesteban
Java-Plattform-Entwickler

Tel.: (030) 74921026
Priv. Tel.: (030) 470 03 470
Mobil: 01577 2856 033
E-Mail: rodant68@googlemail.com

ricky@ricky-desktop:~$ cat test.groovy
class Main
{
public static void main(String[] args)
{
int i = "hello";
}
}
ricky@ricky-desktop:~$ groovy-1.6.3/bin/groovyc test.groovy
ricky@ricky-desktop:~$ java -classpath groovy-1.6.3/lib/groovy-1.6.3.jar:. Main
Exception in thread "main"
org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot
cast object 'hello' with class 'java.lang.String' to class
'java.lang.Integer'
at org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToNumber(DefaultTypeTransformation.java:132)
at org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToType(DefaultTypeTransformation.java:261)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.castToType(ScriptBytecodeAdapter.java:598)
at Main.main(test.groovy:5)

2009/6/16 Antonio Rodríguez S. :
> If I got it right, it was a year ago, if you use the Groovy compiler you
> should get a compilation error for int x = "hello". If you use the
> interpreter otherwise, a ClassCastException should occur.
>
> Cheers.
>
> 2009/6/16 Ricky Clarkson
>>
>> Groovy's static typing is not optional, but non-existent.
>>
>> int x = "hello"; is valid Groovy.  It compiles, but throws an
>> exception.  That's not static typing, but a syntax for runtime
>> assertions.
>>
>> 2009/6/16 Antonio Rodríguez S. :
>> > Hello Andreas,
>> >
>> > first welcome to Scala!. I also learned Groovy before moving to Scala. I
>> > think Groovy is also a powerful language sharing many features with
>> > Scala,
>> > but one big difference for me is the static typing of Scala (a very
>> > important language feature for large, mission critical projects), in
>> > Groovy
>> > it is only optional and if you use it you lose much of the power. In
>> > Scala
>> > it is not the case, you have the power despite of static typing. This is
>> > one
>> > of the great innovations in Scala, I think. Another point is Scala's
>> > performance, which is similar to Java and better suited for multi-core
>> > systems.
>> >
>> > I think I get the sense of Dirk Koenigs statement, I didn't heard
>> > before,
>> > Groovy uses the same type system as Java and "extends" the syntax, they
>> > are
>> > very close to each other. Scala is a little apart but still running in
>> > the
>> > JVM (the highway).
>> >
>> > I hope, this helps you a little. Surely you will get other comments from
>> > the
>> > community.
>> >
>> > Viel Spaß mit Scala!
>> > Antonio R. Rodríguez Santiesteban.
>> >
>> > 2009/6/16 Andreas Jöcker
>> >>
>> >> Hi all,
>> >>
>> >> I just started to discover Scala and out of curiosity I try to
>> >> understand what is unique in scala or in what ways it is
>> >> better/simpler/more intuitive to use.
>> >>
>> >> I'm coming from the Java corner and during the last weeks I learned
>> >> about Groovy and all its features.
>> >>
>> >> When I first encountered Scala I was surprised by the different syntax
>> >> but thats just a question of using it.
>> >>
>> >> My essentiell problem for understanding is - what is unique / special
>> >> about scala.
>> >>
>> >> First I thought it has the same ideas than groovy, but apparently the
>> >> even the concepts are different.
>> >>
>> >> Dirk Koenig, a groovianer, wrote once (talking about conceptionally
>> >> differences of Java / Scala and Groovy)
>> >>
>> >> > Groovy and Java share the same car.
>> >> > Scala is driving on the same highway.
>> >>
>> >> Would you agree and the most important question:
>> >>
>> >> What car are you driving ?
>> >>
>> >> Cheers
>> >> A
>> >>
>> >> PS: I'm trying to find the place for Scala in my language world -
>> >> hopefully you can help me here ;-)
>> >>
>> >> --
>> >>
>> >> Andreas Jöcker
>> >> GiS - Gesellschaft für integrierte Systemplanung mbH
>> >> Junkersstr. 2
>> >> 69469 Weinheim
>> >>
>> >> E-Mail   a.joecker@gis-systemhaus.de
>> >> Telefon +49 6201 503-59
>> >> Fax     +49 6201 503-66
>> >>
>> >> Gesellschaft für integrierte Systemplanung mbH
>> >> Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
>> >> Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
>> >> Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435
>> >>
>> >
>> >
>> >
>> > --
>> > Dr. Antonio R. Rodríguez Santiesteban
>> > Java-Plattform-Entwickler
>> >
>> > Tel.: (030) 74921026
>> > Priv. Tel.: (030) 470 03 470
>> > Mobil: 01577 2856 033
>> > E-Mail: rodant68@googlemail.com
>> >
>
>
>
> --
> Dr. Antonio R. Rodríguez Santiesteban
> Java-Plattform-Entwickler
>
> Tel.: (030) 74921026
> Priv. Tel.: (030) 470 03 470
> Mobil: 01577 2856 033
> E-Mail: rodant68@googlemail.com
>

Well, this only enforce my desition for Scala as my favorit language for the JVM;-) I'm asking me, what is the type annotation in Groovy for?

Cheers.

2009/6/16 Ricky Clarkson <ricky.clarkson@gmail.com>

ricky@ricky-desktop:~$ cat test.groovy
class Main
{
       public static void main(String[] args)
       {
               int i = "hello";
       }
}
ricky@ricky-desktop:~$ groovy-1.6.3/bin/groovyc test.groovy
ricky@ricky-desktop:~$ java -classpath groovy-1.6.3/lib/groovy-1.6.3.jar:. Main
Exception in thread "main"
org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot
cast object 'hello' with class 'java.lang.String' to class
'java.lang.Integer'
       at org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToNumber(DefaultTypeTransformation.java:132)
       at org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToType(DefaultTypeTransformation.java:261)
       at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.castToType(ScriptBytecodeAdapter.java:598)
       at Main.main(test.groovy:5)


2009/6/16 Antonio Rodríguez S. <rodant68@googlemail.com>:
> If I got it right, it was a year ago, if you use the Groovy compiler you
> should get a compilation error for int x = "hello". If you use the
> interpreter otherwise, a ClassCastException should occur.
>
> Cheers.
>
> 2009/6/16 Ricky Clarkson <ricky.clarkson@gmail.com>
>>
>> Groovy's static typing is not optional, but non-existent.
>>
>> int x = "hello"; is valid Groovy.  It compiles, but throws an
>> exception.  That's not static typing, but a syntax for runtime
>> assertions.
>>
>> 2009/6/16 Antonio Rodríguez S. <rodant68@googlemail.com>:
>> > Hello Andreas,
>> >
>> > first welcome to Scala!. I also learned Groovy before moving to Scala. I
>> > think Groovy is also a powerful language sharing many features with
>> > Scala,
>> > but one big difference for me is the static typing of Scala (a very
>> > important language feature for large, mission critical projects), in
>> > Groovy
>> > it is only optional and if you use it you lose much of the power. In
>> > Scala
>> > it is not the case, you have the power despite of static typing. This is
>> > one
>> > of the great innovations in Scala, I think. Another point is Scala's
>> > performance, which is similar to Java and better suited for multi-core
>> > systems.
>> >
>> > I think I get the sense of Dirk Koenigs statement, I didn't heard
>> > before,
>> > Groovy uses the same type system as Java and "extends" the syntax, they
>> > are
>> > very close to each other. Scala is a little apart but still running in
>> > the
>> > JVM (the highway).
>> >
>> > I hope, this helps you a little. Surely you will get other comments from
>> > the
>> > community.
>> >
>> > Viel Spaß mit Scala!
>> > Antonio R. Rodríguez Santiesteban.
>> >
>> > 2009/6/16 Andreas Jöcker <a.joecker@gis-systemhaus.de>
>> >>
>> >> Hi all,
>> >>
>> >> I just started to discover Scala and out of curiosity I try to
>> >> understand what is unique in scala or in what ways it is
>> >> better/simpler/more intuitive to use.
>> >>
>> >> I'm coming from the Java corner and during the last weeks I learned
>> >> about Groovy and all its features.
>> >>
>> >> When I first encountered Scala I was surprised by the different syntax
>> >> but thats just a question of using it.
>> >>
>> >> My essentiell problem for understanding is - what is unique / special
>> >> about scala.
>> >>
>> >> First I thought it has the same ideas than groovy, but apparently the
>> >> even the concepts are different.
>> >>
>> >> Dirk Koenig, a groovianer, wrote once (talking about conceptionally
>> >> differences of Java / Scala and Groovy)
>> >>
>> >> > Groovy and Java share the same car.
>> >> > Scala is driving on the same highway.
>> >>
>> >> Would you agree and the most important question:
>> >>
>> >> What car are you driving ?
>> >>
>> >> Cheers
>> >> A
>> >>
>> >> PS: I'm trying to find the place for Scala in my language world -
>> >> hopefully you can help me here ;-)
>> >>
>> >> --
>> >>
>> >> Andreas Jöcker
>> >> GiS - Gesellschaft für integrierte Systemplanung mbH
>> >> Junkersstr. 2
>> >> 69469 Weinheim
>> >>
>> >> E-Mail   a.joecker@gis-systemhaus.de
>> >> Telefon +49 6201 503-59
>> >> Fax     +49 6201 503-66
>> >>
>> >> Gesellschaft für integrierte Systemplanung mbH
>> >> Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
>> >> Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
>> >> Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435
>> >>
>> >
>> >
>> >
>> > --
>> > Dr. Antonio R. Rodríguez Santiesteban
>> > Java-Plattform-Entwickler
>> >
>> > Tel.: (030) 74921026
>> > Priv. Tel.: (030) 470 03 470
>> > Mobil: 01577 2856 033
>> > E-Mail: rodant68@googlemail.com
>> >
>
>
>
> --
> Dr. Antonio R. Rodríguez Santiesteban
> Java-Plattform-Entwickler
>
> Tel.: (030) 74921026
> Priv. Tel.: (030) 470 03 470
> Mobil: 01577 2856 033
> E-Mail: rodant68@googlemail.com
>

--
Dr. Antonio R. Rodríguez Santiesteban
Java-Plattform-Entwickler

E-Mail: rodant68@googlemail.com

A runtime assertion, like I said. Hilariously, in Groovy explicit
typing makes your code slower.

Scala and Groovy are not competitors.

2009/6/16 Antonio Rodríguez S. :
> Well, this only enforce my desition for Scala as my favorit language for the
> JVM;-) I'm asking me, what is the type annotation in Groovy for?
>
> Cheers.
>
> 2009/6/16 Ricky Clarkson
>>
>> ricky@ricky-desktop:~$ cat test.groovy
>> class Main
>> {
>>        public static void main(String[] args)
>>        {
>>                int i = "hello";
>>        }
>> }
>> ricky@ricky-desktop:~$ groovy-1.6.3/bin/groovyc test.groovy
>> ricky@ricky-desktop:~$ java -classpath groovy-1.6.3/lib/groovy-1.6.3.jar:.
>> Main
>> Exception in thread "main"
>> org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot
>> cast object 'hello' with class 'java.lang.String' to class
>> 'java.lang.Integer'
>>        at
>> org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToNumber(DefaultTypeTransformation.java:132)
>>        at
>> org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToType(DefaultTypeTransformation.java:261)
>>        at
>> org.codehaus.groovy.runtime.ScriptBytecodeAdapter.castToType(ScriptBytecodeAdapter.java:598)
>>        at Main.main(test.groovy:5)
>>
>>
>> 2009/6/16 Antonio Rodríguez S. :
>> > If I got it right, it was a year ago, if you use the Groovy compiler you
>> > should get a compilation error for int x = "hello". If you use the
>> > interpreter otherwise, a ClassCastException should occur.
>> >
>> > Cheers.
>> >
>> > 2009/6/16 Ricky Clarkson
>> >>
>> >> Groovy's static typing is not optional, but non-existent.
>> >>
>> >> int x = "hello"; is valid Groovy.  It compiles, but throws an
>> >> exception.  That's not static typing, but a syntax for runtime
>> >> assertions.
>> >>
>> >> 2009/6/16 Antonio Rodríguez S. :
>> >> > Hello Andreas,
>> >> >
>> >> > first welcome to Scala!. I also learned Groovy before moving to
>> >> > Scala. I
>> >> > think Groovy is also a powerful language sharing many features with
>> >> > Scala,
>> >> > but one big difference for me is the static typing of Scala (a very
>> >> > important language feature for large, mission critical projects), in
>> >> > Groovy
>> >> > it is only optional and if you use it you lose much of the power. In
>> >> > Scala
>> >> > it is not the case, you have the power despite of static typing. This
>> >> > is
>> >> > one
>> >> > of the great innovations in Scala, I think. Another point is Scala's
>> >> > performance, which is similar to Java and better suited for
>> >> > multi-core
>> >> > systems.
>> >> >
>> >> > I think I get the sense of Dirk Koenigs statement, I didn't heard
>> >> > before,
>> >> > Groovy uses the same type system as Java and "extends" the syntax,
>> >> > they
>> >> > are
>> >> > very close to each other. Scala is a little apart but still running
>> >> > in
>> >> > the
>> >> > JVM (the highway).
>> >> >
>> >> > I hope, this helps you a little. Surely you will get other comments
>> >> > from
>> >> > the
>> >> > community.
>> >> >
>> >> > Viel Spaß mit Scala!
>> >> > Antonio R. Rodríguez Santiesteban.
>> >> >
>> >> > 2009/6/16 Andreas Jöcker
>> >> >>
>> >> >> Hi all,
>> >> >>
>> >> >> I just started to discover Scala and out of curiosity I try to
>> >> >> understand what is unique in scala or in what ways it is
>> >> >> better/simpler/more intuitive to use.
>> >> >>
>> >> >> I'm coming from the Java corner and during the last weeks I learned
>> >> >> about Groovy and all its features.
>> >> >>
>> >> >> When I first encountered Scala I was surprised by the different
>> >> >> syntax
>> >> >> but thats just a question of using it.
>> >> >>
>> >> >> My essentiell problem for understanding is - what is unique /
>> >> >> special
>> >> >> about scala.
>> >> >>
>> >> >> First I thought it has the same ideas than groovy, but apparently
>> >> >> the
>> >> >> even the concepts are different.
>> >> >>
>> >> >> Dirk Koenig, a groovianer, wrote once (talking about conceptionally
>> >> >> differences of Java / Scala and Groovy)
>> >> >>
>> >> >> > Groovy and Java share the same car.
>> >> >> > Scala is driving on the same highway.
>> >> >>
>> >> >> Would you agree and the most important question:
>> >> >>
>> >> >> What car are you driving ?
>> >> >>
>> >> >> Cheers
>> >> >> A
>> >> >>
>> >> >> PS: I'm trying to find the place for Scala in my language world -
>> >> >> hopefully you can help me here ;-)
>> >> >>
>> >> >> --
>> >> >>
>> >> >> Andreas Jöcker
>> >> >> GiS - Gesellschaft für integrierte Systemplanung mbH
>> >> >> Junkersstr. 2
>> >> >> 69469 Weinheim
>> >> >>
>> >> >> E-Mail   a.joecker@gis-systemhaus.de
>> >> >> Telefon +49 6201 503-59
>> >> >> Fax     +49 6201 503-66
>> >> >>
>> >> >> Gesellschaft für integrierte Systemplanung mbH
>> >> >> Geschäftsführer: Eckhard Haffmann, Alfred Gai, Bernd Heselmann
>> >> >> Sitz der Gesellschaft: Zeppelinstr. 11 - 91052 Erlangen
>> >> >> Amtsgericht Fürth/Bayern - Handelsregister-Nr. HRB 3435
>> >> >>
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Dr. Antonio R. Rodríguez Santiesteban
>> >> > Java-Plattform-Entwickler
>> >> >
>> >> > Tel.: (030) 74921026
>> >> > Priv. Tel.: (030) 470 03 470
>> >> > Mobil: 01577 2856 033
>> >> > E-Mail: rodant68@googlemail.com
>> >> >
>> >
>> >
>> >
>> > --
>> > Dr. Antonio R. Rodríguez Santiesteban
>> > Java-Plattform-Entwickler
>> >
>> > Tel.: (030) 74921026
>> > Priv. Tel.: (030) 470 03 470
>> > Mobil: 01577 2856 033
>> > E-Mail: rodant68@googlemail.com
>> >
>
>
>
> --
> Dr. Antonio R. Rodríguez Santiesteban
> Java-Plattform-Entwickler
>
> E-Mail: rodant68@googlemail.com
>

Groovy's type annotations are check dynamically.  Groovy does not have static typing, optional or otherwise.

On Tue, Jun 16, 2009 at 4:23 AM, Antonio Rodríguez S. <rodant68@googlemail.com> wrote:

 big difference for me is the static typing of Scala (a very important language feature for large, mission critical projects), in Groovy it is only optional and if you use it you lose much of the power.

On Tue, 2009-06-16 at 14:22 +0100, Ricky Clarkson wrote:
> A runtime assertion, like I said. Hilariously, in Groovy explicit
> typing makes your code slower.

Type annotations in Groovy are more than this and in many situation make
the code run much faster. You cannot have method overloading without
the type annotations. If you need the primitive types for computation
speed you need the type annotations. There are other cases.

I have to admit I feel a little annoyed by your slurs on Groovy,
especially given your next statement:

> Scala and Groovy are not competitors.

I don't think it is quite as black and white as this but basically it is
true, Scala and Groovy are unlikely to be competing options for most
cases where Scala is a prime candidate. There is therefore absolutely
no need for either side to distribute FUD about the other.

Scala and Groovy are both fine languages in their own right. They have
different semantics and properties, and are likely used in different
situations that are generally mutually exclusive. The communities
should be supportive of each other, not trying to attack each other.

This goes for Java, Jython, JRuby, and Clojure as well. And indeed
Fortran and C++.

http://stackoverflow.com/questions/711913/what-are-the-key-differences-between-scala-and-groovy

On Tue, Jun 16, 2009 at 4:00 AM, Andreas Jöcker <a.joecker@gis-systemhaus.de> wrote:

Dirk Koenig, a groovianer, wrote once (talking about conceptionally
differences of Java / Scala and Groovy)

> Groovy and Java share the same car.
> Scala is driving on the same highway.

Would you agree and the most important question:

What car are you driving ?

Please tell me what I said about Groovy that is a slur.

2009/6/16 Russel Winder :
> On Tue, 2009-06-16 at 14:22 +0100, Ricky Clarkson wrote:
>> A runtime assertion, like I said.  Hilariously, in Groovy explicit
>> typing makes your code slower.
>
> Type annotations in Groovy are more than this and in many situation make
> the code run much faster.  You cannot have method overloading without
> the type annotations.  If you need the primitive types for computation
> speed you need the type annotations.  There are other cases.
>
> I have to admit I feel a little annoyed by your slurs on Groovy,
> especially given your next statement:
>
>> Scala and Groovy are not competitors.
>
> I don't think it is quite as black and white as this but basically it is
> true, Scala and Groovy are unlikely to be competing options for most
> cases where Scala is a prime candidate.  There is therefore absolutely
> no need for either side to distribute FUD about the other.
>
> Scala and Groovy are both fine languages in their own right.  They have
> different semantics and properties, and are likely used in different
> situations that are generally mutually exclusive.  The communities
> should be supportive of each other, not trying to attack each other.
>
> This goes for Java, Jython, JRuby, and Clojure as well.  And indeed
> Fortran and C++.
>
> --
> Russel.
> =============================================================================
> Dr Russel Winder      Partner
>                                            xmpp: russel@russel.org.uk
> Concertant LLP        t: +44 20 7585 2200, +44 20 7193 9203
> 41 Buckmaster Road,   f: +44 8700 516 084   voip: sip:russel.winder@ekiga.net
> London SW11 1EN, UK   m: +44 7770 465 077   skype: russel_winder
>

Hello Russel,

I don't want to make Groovy bad. When I started learning Groovy I was even very enthusiastic about it, but the more I learn about it, the more I see things, which are disappointing, this thread is also an example for that. I think, it must be possible to say what I think, without to be understood as an attack to Groovy or other language. And my opinion is, that there is only a few situations where I would prefer Groovy instead of Scala, for example if I wanna use Gant, but most of the cases my choice would be Scala. Scala is also suitable for scripting, for example.

Cheers,
Antonio.

2009/6/16 Russel Winder <russel.winder@concertant.com>

On Tue, 2009-06-16 at 14:22 +0100, Ricky Clarkson wrote:
> A runtime assertion, like I said.  Hilariously, in Groovy explicit
> typing makes your code slower.

Type annotations in Groovy are more than this and in many situation make
the code run much faster.  You cannot have method overloading without
the type annotations.  If you need the primitive types for computation
speed you need the type annotations.  There are other cases.

I have to admit I feel a little annoyed by your slurs on Groovy,
especially given your next statement:

> Scala and Groovy are not competitors.

I don't think it is quite as black and white as this but basically it is
true, Scala and Groovy are unlikely to be competing options for most
cases where Scala is a prime candidate.  There is therefore absolutely
no need for either side to distribute FUD about the other.

Scala and Groovy are both fine languages in their own right.  They have
different semantics and properties, and are likely used in different
situations that are generally mutually exclusive.  The communities
should be supportive of each other, not trying to attack each other.

This goes for Java, Jython, JRuby, and Clojure as well.  And indeed
Fortran and C++.

--
Russel.
=============================================================================
Dr Russel Winder      Partner
                                           xmpp: russel@russel.org.uk
Concertant LLP        t: +44 20 7585 2200, +44 20 7193 9203
41 Buckmaster Road,   f: +44 8700 516 084   voip: 3Arussel [dot] winder [at] ekiga [dot] net" rel="nofollow">sip:russel.winder@ekiga.net
London SW11 1EN, UK   m: +44 7770 465 077   skype: russel_winder

--
Dr. Antonio R. Rodríguez Santiesteban
Java-Plattform-Entwickler

Tel.: (030) 74921026
Priv. Tel.: (030) 470 03 470
Mobil: 01577 2856 033
E-Mail: rodant68@googlemail.com

Scala and Groovy are not competitors.

And the Highway metaphor doesn't work for me either.

I feel Java, Scala and Groovy spanning a triangle.

While Java is the rudimentary thing providing all
the little and not-so-little libraries even the other
JVM-languages are sitting on (*), Scala and Groovy overlap
in very different manners with it AFAIC.

Groovy is dynamic, so Ducktyping is a matter there. Not so
with the other two.

Groovy works extraordinarily well as a scripting language
(we use it for ant internal scripting, ad hoc scripting
in our codegenerator, doing funny scripting stuff with
the GroovyConsole embedded in our application desktop,
and even the codegenerator, extending TWIKI-pages
with dynamic stuff, and use it as configuration and
extension language for our proprietary SDE-Frontend.)

It is very flexible if you want to do highly dynamical
stuff (see the Builder things: SwingBuilder and AntBuilder
do extremely well in quick-and-short scripting scenarios).

But I would not want to write larger and more complex
applications in it. I had once the task to refactor a
colleague's "Script" which had grown to a respectable
size, and that was the hell.

Than there is Scala, with very interesting concepts,
giving me not only a programming language but also a
good bunch of teaching on the way. I would indeed trust
it for large and complex applications (to be honest,
my dream would be to try to rewrite our codegenerator
in it ;-) ).
The Actor thing has already helped me improve performance
on a multi-core for a short-time task as I was able to
implement concurrency without deep study in some few
lines of code.
So that experiences differ from Java as well as Groovy.

When it comes to ad-hoc scripting and downscale,
Groovy-solutions always seem easier and more fluent.
Some problems in Scala are lack of good scriptic libraries
and will shurely be targeted in the future if Scala gets
more and more attention.
(Even the GroovyConsole has seen an alpha-pendant, even
if not in the main distribution).
Another important thing will be a good JSR-223 compliance,
to bring Scala more into that area.

There would be more to say about that triangle, but
let that be enough for now.

KR
Det

Summary: Groovy/Scala: I love both.

* It's funny that Scala is called "the next Java", while
no language really gets rid of the libraries, but only
wraps them by compiler sugar or own classes.
Would like to see only one JVM-language coming up with own
ideas for e.g. a GUI library.
Or other approach: Which language uses the java.exe but not
the rt.jar?

On Tue, 2009-06-16 at 15:08 +0100, Ricky Clarkson wrote:
> Please tell me what I said about Groovy that is a slur.

The phraseology and tone of your emails was clearly intended to be that
of ridicule.

Groovy has its problems, but so do all programming languages.
Constructive critique has an important place in the world. Ridicule as
an attempt to influence people's opinions of a programming language have
no place in professional society.

I propose that if you want to take this further it be done off list.

On Tue, 2009-06-16 at 16:33 +0200, Antonio Rodríguez S. wrote:
> Hello Russel,
>
> I don't want to make Groovy bad. When I started learning Groovy I was
> even very enthusiastic about it, but the more I learn about it, the
> more I see things, which are disappointing, this thread is also an
> example for that. I think, it must be possible to say what I think,
> without to be understood as an attack to Groovy or other language. And
> my opinion is, that there is only a few situations where I would
> prefer Groovy instead of Scala, for example if I wanna use Gant, but
> most of the cases my choice would be Scala. Scala is also suitable for
> scripting, for example.
>
No argument from me. You contributions were about your experience and
perception, stated matter of factly. All opinions expressed in a
professional way are input data to others decision making.

+1

When it comes to ad-hoc scripting and downscale,
Groovy-solutions always seem easier and more fluent.
Some problems in Scala are lack of good scriptic libraries
and will shurely be targeted in the future if Scala gets
more and more attention.
(Even the GroovyConsole has seen an alpha-pendant, even
if not in the main distribution).
Another important thing will be a good JSR-223 compliance,
to bring Scala more into that area.

I'd love to see more scripting utilities for Scala. IMO it is much better suited for scripting within applications. The compiler can do a great job of protecting you from mistakes and is half and IDE in itself. You only need some code highlighting and you have nice script environment in your application.

It will be also great to have a Scala Server Pages facility or a servlet that compiles Scala scripts on the fly as in Groovy.

I think you might have overreacted to the word 'hilariously'.

It is actually hilarious, as in "I laughed aloud when I first saw it".
I couldn't believe they were calling it "Java but better" when
explicit types are not checked at compile time and slow code down
(though someone pointed out that they sometimes speed it up). I did
sit there and laugh at the computer.

Have a nice day.

2009/6/17 Russel Winder :
> On Tue, 2009-06-16 at 15:08 +0100, Ricky Clarkson wrote:
>> Please tell me what I said about Groovy that is a slur.
>
> The phraseology and tone of your emails was clearly intended to be that
> of ridicule.
>
> Groovy has its problems, but so do all programming languages.
> Constructive critique has an important place in the world.  Ridicule as
> an attempt to influence people's opinions of a programming language have
> no place in professional society.
>
> I propose that if you want to take this further it be done off list.
>
> --
> Russel.
> =============================================================================
> Dr Russel Winder      Partner
>                                            xmpp: russel@russel.org.uk
> Concertant LLP        t: +44 20 7585 2200, +44 20 7193 9203
> 41 Buckmaster Road,   f: +44 8700 516 084   voip: sip:russel.winder@ekiga.net
> London SW11 1EN, UK   m: +44 7770 465 077   skype: russel_winder
>