Op 04-12-13 11:09, rusi schreef: > On Wednesday, December 4, 2013 2:27:28 PM UTC+5:30, Ian wrote: >> On Tue, Dec 3, 2013 at 11:31 PM, rusi wrote: >>> Its a more fundamental problem than that: >>> It emerges from the OP's second post) that he wants '-' in the attributes. >>> Is that all? >>> >>> Where does this syntax-enlargement stop? Spaces? Newlines? >> >> At non-strings. >> >>>>> setattr(foo, 21+21, 42) >> Traceback (most recent call last): >> File "<stdin>", line 1, in <module> >> TypeError: attribute name must be string, not 'int' > > Not sure what's your point. > > OP wants attribute identifiers like outer_fieldset-inner_fieldset-third_field. > Say I have a python expression: > obj.outer_fieldset-inner_fieldset-third_field > > It can (in the proposed extension) be parsed as above, or as: > obj.outer_fieldset - inner_fieldset-third_field > the first hyphen being minus and the second being part of the identifier. > > How do we decide which '-' are valid identifier components -- hyphens > and which minus-signs? > > So to state my point differently: > The grammar of python is well-defined > It has a 'sub-grammar' of strings that is completely* free-for-all ie just > about anything can be put into a string literal. > The border between the orderly and the wild world are the quote-marks. > Remove that border and you get complete grammatical chaos. > [Maybe I should have qualified my reference to 'spaces'. > Algol-68 allowed spaces in identifiers (for readability!!) > The result was chaos] > > 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. -- Antoon Pardon -- https://mail.python.org/mailman/listinfo/python-list
