The following:
span.M
generates nicely into:
<span class='M'>
However,
span.glyphicon glyphicon-book
does not work.
Is that a way to save typing and shifting for class names similar to the latter?
The pug engine does render code blocks of the type:
span.glyphicon-glyphicon-book
However, I think when you say not working, you mean that the glyphicon is not being replace. For that, you need to have two different classes like so:
span.glyphicon.glyphicon-book