30 Mar

Trailing white space in TextMate

Trailing white space in TextMate has been bugging the hell out of me in recently, until Dominic Mitchell bookmarked this awesome tip.

I've decided to take the tip one step further.

The idea is to create a base layer grammar, and have it inherited by all the languages you want some common patterns to be matched.

Common Grammar

Start by creating a new language grammar. I've created it in the Source folder and called it source - but you can call it what you like.

I've added the trailing space pattern, with a slight twist on Britt's version, in that I'm only looking for trailing space (2 spaces or more) on lines I have code on (i.e. I don't care about blank lines):

{
  scopeName = 'source';
  patterns = (
    { name = 'source.invalid.trailing-whitespace';
      match = '\S(\s{2,})$';
      captures = { 1 = { name = 'invalid.trailing-whitespace'; }; };
    },
  );
}

It's a same we can't use scopeName = 'source.*' and have TextMate use namespacing to handling the inheriting.

Inherit

Now in each language you want to make use of this grammar, add the following to the patterns lists:

patterns = (
  { include = 'source'; },
  // patterns continue...

I've included this in my JavaScript bundle, HTML bundle and so on.

Highlight

As Britt's post shows, you can now highlight the nasty lines as such via the preferences:

Highlighting trailing white space

Wrap Up

Now that you've got a common language grammar, you can add any number of extra matches that make programming that little bit more enjoyable...not that I can think of any just yet

You should follow me on Twitter here I'll tweet about JavaScript, HTML 5 and other such gems (amongst usual tweet-splurges)

7 Responses to “Trailing white space in TextMate”

Ville Säävuori April 3rd, 2008 at 8:44 am

This is brilliant!

I cannot seem to get it work with Python bundle, but it works great with HTML and JavaScript.
Blog Author Remy Sharp April 3rd, 2008 at 12:21 pm

@Ville - that is odd. I've tried the include rule in a few different places and I've tried including the entire rule and it doesn't seem to apply.

I'm not familiar with Python (yet) - but isn't there language rules that mean white space has a meaning? Could there be a rule in the grammar accounting for this and overwriting the white space rule?
Ville Säävuori April 3rd, 2008 at 8:01 pm

@Remy, yes, I suspect that it has something to do with whitespace rules in Python. From Wikipedia (which is much better in English than I am "Python uses indentation/whitespace, rather than curly braces or keywords, to delimit statement blocks. An increase in indentation comes after certain statements; a decrease in indentation signifies the end of the current block."

I've tested this with Python grammar and Django/Python grammar and it doesn't seem to work with either of them. I'm not saying "fix this, it doesn't work!" but just noting the fact. Thanks for the great tip, anyway!
farid aliev April 18th, 2008 at 1:32 am

just wanted to add that i've spent some time trying to add this to default php language definition in textmate and it was rough because if you add it to first pattern section this does not work.

to make it work you have to find " language = " and add { include = 'source'; } there.
Still i could find a way to make this work with comments. If anyone can figure out how to make it work with comments in php documentation please post solution here. thx in advance

Jochen Rau January 28th, 2010 at 12:39 am

I'd like to add a variant of the RegEx. It takes tabs into account but ignores tabs and white space on an empty line.


{	scopeName = 'source';
	patterns = (
		{	name = 'source.invalid.trailing-whitespace';
			match = '((?<!^)[	s]*)$';
			captures = { 1 = { name = 'invalid.trailing-whitespace'; }; };
		},
	);
}

Thanks for sharing your idea!

written by Britt Selvitelle » Archive » Trailing Whitespace in Textmate March 9th, 2011 at 9:34 pm

[...] Remy Sharp followed this up with a great way to define the pattern across all languages with an include, even though he calls me Luke [...]
Noname May 13th, 2011 at 2:38 pm

The designated scope identifier is »invalid.deprecated.trailing-whitespace« (cf. Mac Classic theme).