On Wednesday, December 4, 2013 6:02:18 PM UTC+5:30, Antoon Pardon wrote: > Op 04-12-13 13:01, rusi schreef: > > On Wednesday, December 4, 2013 3:59:06 PM UTC+5:30, Antoon Pardon wrote: > >> Op 04-12-13 11:09, rusi schreef: > >>> I used the spaces case to indicate the limit of chaos. > >>> Other characters (that > >>> already have uses) are just as problematic. > >> > >> I don't agree with the latter. As it is now python can make the > >> distinction between > >> > >> from A import B and fromAimportB. > >> > >> I see no a priori reason why this should be limited to letters. A > >> language designer might choose to allow a bigger set of characters > >> in identifiers like '-', '+' and others. In that case a-b would be > >> an identifier and a - b would be the operation. Just as in python > >> fromAimportB is an identifier and from A import B is an import > >> statement. > > > > Im not sure what you are saying. > > Sure a language designer can design a language differently from python. > > I mentioned lisp. Cobol is another behaving exactly as you describe. > > > > My point is that when you do (something like) that, you will need to change > > the > > lexical and grammatical structure of the language. And this will make > > for rather far-reaching changes ALL OVER the language not just in > > what-follows-dot. > > No you don't need to change the lexical and grammatical structure of > the language. Changing the characters allowed in identifiers, is not a > change in lexical structure. The only difference in lexical structuring > would be that '-', '>=' and other similars symbols would have to be > treated like keyword like 'from', 'as' etc instead of being recognizable > by just being present.
Well I am mystified… Consider the string a-b in a program text. A Cobol or Lisp system sees this as one identifier. Python, C (and most modern languages) see this ident, operator, ident. As I understand it this IS the lexical structure of the language and the lexer is the part that implements this: - in cobol/lisp keeping it as one - in python/C breaking it into 3 Maybe you understand in some other way the phrase "lexical structure"? > And the grammatical structure of the language wouldn't change at all. > Sure a-b would now be an identifier and not an operation but that is > of no concern for the parser. About grammar maybe what you are saying will hold: presumably if the token-set is the same, one could keep the same grammar, with the differences being entirely inter-lexeme ones. -- https://mail.python.org/mailman/listinfo/python-list
