Yes, it would be an error, and yes, difficult to understand. Possibly an implementation would give a better error message than "syntax error", preferably something along the lines of "inconsistent indent. Indent at line X was <tab><space><space>, next line is <space><space><tab>" (i.e. display the error using "<tab>" instead of "\t"), and possibly (if on a terminal) highlight the first nonmatching character especially on deep indentations.

On Fri, May 3, 2013 at 9:02 AM, David Vanderson <xxxxxx@gmail.com> wrote:

For example, if your editor had a tab-width of 2:

[tab][space][space]define foo()
[space][space][tab] "bar"

My reading of the spec says this would be an error, but it would be especially difficult to understand, because there's no visual difference. Am I missing something, or has this already been discussed elsewhere?

Thanks,
Dave