Tell me more ×
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required.
up vote 2 down vote favorite
1

Apart from serious performance problems, Scala is a very powerful language. Therefore I am now using it frequently for scripted tasks inside Bash. Is there a way to just execute a *.scala file exactly the way I can do with Python files? As far as I know, Python uses bytecode to execute programs, exactly like the JVM does. However, there is not anything called pythonc (like scalac or javac) I need to call in order to accomplish this. Hence I expect Scala to be able to act in a similar manner.

share|improve this question
Possible duplicate of stackoverflow.com/questions/7620144 ? – Richard Sitze 22 hours ago
I'm not sure what quantitative meaning to attach to "serious," but Scala approximates the performance of other JVM languages when used without particular attention to performance and is very competitive with Java when you apply appropriate optimizations to empirically determined hot-spots. Of course, if you include JVM start-up time, it does not compare favorably with native code or even conventional interpreted languages such as Python or Perl. But when you compile the code every time you run a "script," it would try anyone's patience—Don't do that. – Randall Schulz 4 hours ago

1 Answer

up vote 1 down vote accepted

I don't use python, but in Scala, the most scripty thing I can do is this: 

thinkpux:~/proj/mini/forum > echo 'println(" 3 + 4 = " + (3 + 4))' | scala 
Welcome to Scala version 2.10.2 (Java HotSpot(TM) Server VM, Java 1.7.0_09).
Type in expressions to have them evaluated.
Type :help for more information.

scala> println(" 3 + 4 = " + (3 + 4))
 3 + 4 = 7

scala> thinkpux:~/proj/mini/forum >

However, afterwards, I don't have visual feedback in the bash, so I have to call 'clear'.

But there is no problem in writing a script and executing that: 

thinkpux:~/proj/mini/forum > echo 'println(" 3 + 4 = " + (3 + 4))' > print7.scala 
thinkpux:~/proj/mini/forum > scala print7.scala 
 3 + 4 = 7

Then, there aren't issues with the shell.

With an enclosing class, the code wouldn't be executed: 

thinkpux:~/proj/mini/forum > echo -e 'class Foo {\nprintln(" 3 + 4 = " + (3 + 4))\n}\n'
class Foo {
println(" 3 + 4 = " + (3 + 4))
}

thinkpux:~/proj/mini/forum > scala Foo.scala 
thinkpux:~/proj/mini/forum > cat Foo.scala 
class Foo {
println(" 3 + 4 = " + (3 + 4))
}

But with instatiating a class, you can execute code in it, without using the wellknown (hope so) 'main' way:

thinkpux:~/proj/mini/forum > echo -e 'class Foo {\nprintln(" 3 + 4 = " + (3 + 4))\n}\nval foo = new Foo()'  > Foo.scala
thinkpux:~/proj/mini/forum > cat Foo.scala 
class Foo {
println(" 3 + 4 = " + (3 + 4))
}
val foo = new Foo()
thinkpux:~/proj/mini/forum > scala Foo.scala 
 3 + 4 = 7
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.