Support whitespace control

[justinbmeyer]

From: canjs/canjs#2284

If not yet supported, please support whitespace control like Handlebars: http://handlebarsjs.com/expressions.html#whitespace-control

My use case: :empty pseudo selector, which does not match

<div> </div>

<div>
  <!-- test -->
</div>

<div>
</div>

Background:

• https://css-tricks.com/almanac/selectors/e/empty/
• http://thenewcode.com/692/Vanishing-Acts-The-CSS-empty-Selector
• http://codepen.io/katydecorah/post/a-case-for-empty
• https://stackoverflow.com/questions/15953293/handlebars-whitespace-control ⇒ Unecessary Whitespace handlebars-lang/handlebars.js#336

[justinbmeyer]

This would have to use some other syntax. ~ is reserved for computes.

[justinbmeyer]

Thumbs up if people would like us to prioritize!

[drecdroid]

Jinja solves this adding a minus sign after the opening braces or before the closing braces to remove the whitespace before or after the content.
http://jinja.pocoo.org/docs/dev/templates/#whitespace-control

[Schweinepriester]

As https://github.com/canjs/can-stache/releases/tag/v3.3.0 is out, this probably can be closed? :)