white-space.textile

layout	title
default	White Space

Spaces over Tabs

No tabs, ever.

If you need to clean up a codebase with tabs, you can type the following which converts all tab occurences to 2 spaces:

{% highlight sh }
% find . -name “*.scala” | xargs sed -i ‘s/\t/ /’
{ endhighlight %}

Trailing whitespace

Try to leave no trailing whitespace behind.

If you need help cleaning a codebase, type the following which strips all trailing whitespace (spaces, tabs):

{% highlight sh }
% find . -name “*.scala” | xargs sed -i ‘s/[ \t]*$//’
{ endhighlight %}

Spaces around arguments and operators

One space after commas

{% highlight scala }
// wrong: missing space after comma
def foo(a:Any,b:Ref) = …
{ endhighlight %}

{% highlight scala }
// wrong: extra space before comma
def foo(a:Any ,b:Ref) = …
{ endhighlight %}

{% highlight scala }
// right
def foo(a: Any, b: Ref) = …
{ endhighlight %}

One space after colon

{% highlight scala }
// wrong: missing space after colon
def foo(a:Any,b:Ref) = …
{ endhighlight %}

{% highlight scala }
// wrong: extra space before colon
def foo(a:Any,b :Ref) = …
{ endhighlight %}

{% highlight scala }
// right
def foo(a: Any, b: Ref) = …
{ endhighlight %}

Spaces around operators

{% highlight scala }
// wrong: missing spaces around operator
val x = 1+1
{ endhighlight %}

{% highlight scala }
// right
val x = 1 + 1
{ endhighlight %}

No spaces after parenthesis

{% highlight scala }
// wrong
val threads = 10 + ( Runtime.getRuntime.availableProcessors * 4 )
{ endhighlight %}

{% highlight scala }
// right
val threads = 10 + (Runtime.getRuntime.availableProcessors * 4)
{ endhighlight %}

{% highlight scala }
// right
if (options.has(“?”) || options.has(“h”)) {
parser.printHelpOn(System.out)
System.exit(-1)
}
{ endhighlight %}