Added an example on how to use anonymous functions in the "Anonymous …

[ghost]

…Function Syntax" page (tutorials/tour/anonymous-function-syntax.md).

[ghost]

I didn't know how to compile the code, that is why I asked about it on this page:

https://getsatisfaction.com/scaladocs/topics/how-do-i-check-if-contribution-is-free-of-errors

I noticed in your log you are running a

./scripts/run-tut.sh

script on linux with ruby installed. Since I don't have all this and it's too much effort for the small change I wanted to commit, we can just leave it out.

Thanks anyways for trying to merge my changes.

[SethTisue]

the Travis log shows:

[tut] compiling: ./tutorials/tour/anonymous-function-syntax.md
[tut] *** Error reported at /home/travis/build/scala/scala.github.com/tutorials/tour/anonymous-function-syntax.md:58
<console>:2: error: illegal start of definition
package tour
^

[SethTisue]

I would suggest omitting : Int. (It's idiomatic in Scala to omit type declarations when the type is obvious, as it is here.)

You can omit the semicolon too.

[ghost]

I updated that part.

[SethTisue]

The tut error you're getting will go away if you simply omit this line, which isn't necessary anyway.

[ghost]

I removed the 'package tour'

[SethTisue]

I would suggest that the example avoid using var at all. In idiomatic Scala code, it's not normal for var to appear unless it's truly needed.

[ghost]

I couldn't ommit the var in the two places it appeared, else the code did not compile. I guess it is 'truly needed' in those cases.

[conniec]

You could do something like this to show that a previously incremented val will be incremented again:

println(myInteger) // Prints: 0

val myIncrementedInteger = anonymousIncrementFunction(myInteger)

println(myIncrementedInteger) // Prints: 1

println(anonymousIncrementFunction(myIncrementedInteger)) // Prints: 2

println(anonymousIncrementFunction(anonymousIncrementFunction(myInteger)) // Prints: 2

It is more idiomatic to assign a result to a new val rather than reusing it.

[SethTisue]

Thanks, this is now closer to being mergeable.

But — and I'm sorry, I don't mean to be difficult — but there's really not a good reason to use var here, and it's really not a good idea for introductory Scala materials to send a signal to Scala newcomers that unnecessary use of var is normal, when it really isn't.

[ghost]

hey, thats all right. thanks for the feedback, but i really don't feel comfortable applying your requested change, since the code does not compile on my machine.

i am using eclipse mars with scala ide v4.4.1, i tried both scala library 2.10.6 and 2.11.8 and just to make sure, i additionally tried to compile the code directly in my CMD running the scala interpreter. this is the output of the latter:

`Welcome to Scala version 2.11.6 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_20).
Type in expressions to have them evaluated.
Type :help for more information.

scala> object AnonymousFunction {
|
| /**
| * Method to increment an integer by one.
| /
| anonymousIncrementFunction = ( x : Int ) => x + 1
|
| /*
| * Main method
| * @param args application arguments
| */
| def main( args : Array[String] ) {
|
| // Create an integer to test the anonymous function with
| myInteger = 0
|
| println( myInteger ) // Prints: 0
|
| myInteger = anonymousIncrementFunction( myInteger )
|
| println( myInteger ) // Prints: 1
| }
| }
:12: error: not found: value anonymousIncrementFunction
anonymousIncrementFunction = ( x : Int ) => x + 1
^
:21: error: not found: value myInteger
myInteger = 0
^
:23: error: not found: value myInteger
println( myInteger ) // Prints: 0
^
:25: error: not found: value myInteger
myInteger = anonymousIncrementFunction( myInteger )
^
:27: error: not found: value myInteger
println( myInteger ) // Prints: 1
^
`

are you telling me that this code compiles and runs on your machine without errors, or am i getting something wrong here???

i can change var anonymousIncrementFunction to val anonymousIncrementFunction, but ommiting it completely does not work. i cannot change var myInteger = 0 to val myInteger = 0, since i get a 'reassignment to val' error in the line myInteger = anonymousIncrementFunction( myInteger ).

[SethTisue]

if we want to keep the exact structure of your original code, then we would need two vals, each with a different name.

but what about dodging the issue entirely and just doing:

val plusOne = (x: Int) => x + 1
println(plusOne(0))  // Prints: 1

this seems to me like the core of what your example is trying to convey.

[SethTisue]

oh by the way about getsatisfaction.com, sorry about that, see #645

[SethTisue]

thank you!