`Number#humanize` and `Int#humanize_bytes` should separate number and unit by a space about crystal HOT 1 OPEN

Adding an option to configure a space between value and unit sounds like a good idea.

There are good practical reasons to skip the space in an environment where machine readability matters. Grepping formatted numbers is much easier if you don't have to account for (variations of) whitespace, for example.
So I'd prefer to leave the current behaviour as default. Also to avoid disruptions.

It might make sense to have a simple value like true to indicate having a space. With this option, callers won't have to worry about the details what specific kind of space to use and just say they want the default space. I think the default should be a non-breaking space to avoid inconsistencies around line breaks. Whether thin or normal could be up for debate.

from crystal.