The cause for this thread is mainly a lexical analyzer bug for hex notation. Except for the error in #9617, I'm fine with the current behavior and syntax even with the semi e-ambiguity if you want the scientific notation literal, use no spaces. This is only ambiguous because Julia permits a number literal N to proceed an identifier I as a shortcut for N*I, which is different than many languages and part of Julia's charm. I'd be sorry to see it go.
[0-9]+(.[0-9]+)?e(+|-)?[0-9]+ <---- scientific notation literal 2e+1 is 2x10^1 2e + 1 is 2*e + 1 2e+ 1 is a syntax error because to the lexical analyzer 2e+ is an error without at least 1 trailing digit (no spaces) typing 2e+1 (without the space) and expecting it to mean 2*e + 1 is way over emphasizing the need to not type a space. All of the other language style guides are consistent about this being bad style. Finally consider this *julia> * *2e-1e**0.5436563656918091* This is parsed as (2*10^-1)e = .2e which I assert is the right thing to do.
