title: EBNF - other character or space character?
body: <p>I wonder if there is any way to know if a character is an other character or space character beforehand in EBNF? Right now I have lexed every possible variant at each position in the source string, but it gives me a little headache to have to try all possible interpretations, especially if I have to try all possible production rules as well before knowing if it is an other character or space character.</p>
  
  <p>To clarify: spacebar, ' ', is both space character and other character if one looks in ISO/IEC 14977, I wanted to know if it was possible to check which one it is easier than brute forcing every possible interpretation of the source string.</p>
  
  <p>2018-01-06:
  Perhaps the ambiguity can be resolved by 6.1? The text implicitly says that gap-separators has higher priority than other-characters outside terminal strings, because otherwise they would be a part of the syntax? Or perhaps it defines an equivalence class of syntaxes, modulo space character, or something like that...</p>