String controls

These are special-cased inside Expander: they are run even if we’re prevented from executing (for example, by \iffalse). This is because of the way printed messages are evaluated by TeX. But it’s rather hacky and we should merge that with yex.control.conditional at some point.

Confusingly, \string is not a string control; it’s in yex.control.other.

\errmessage

This is an expandable control.

class yex.control.Errmessage(is_long=False, is_outer=False, name=None, *args, **kwargs)[source]

\message

This is an expandable control.

class yex.control.Message(is_long=False, is_outer=False, name=None, *args, **kwargs)[source]