On May 16, 2007, at 10:30 PM, Talin wrote: > While there has been a lot of discussion as to whether to accept PEP > 3131 as a whole, there has been little discussion as to the specific > details of the PEP. In particular, is it generally agreed that the > Unicode character classes listed in the PEP are the ones we want to > include in identifiers?
One issue I see is that the PEP defines ID_Start and ID_Continue itself. It should not do that, bue instead reference as authoritative the unicode properties ID_Start and ID_Continue defined in the unicode property database. ID_Start is officially: Lu+Ll+Lt+Lm+Lo+Nl+Other_ID_Start and ID_Continue is officially: ID_Start + Mn+Mc+Nd+Pc + Other_ID_Continue The only differences between PEP 3131's definition and the official ones is the Other_* bits. Those are there to ensure the requirement that anything now in ID_Start/ID_Continue will always in the future be in said categories. That is an important feature, and should not be overlooked. Without the supplemental list, a future version of unicode which changes the general class of a character could make a previously valid identifier become invalid. The list currently includes the following entries: 2118 ; Other_ID_Start # So SCRIPT CAPITAL P 212E ; Other_ID_Start # So ESTIMATED SYMBOL 309B..309C ; Other_ID_Start # Sk [2] KATAKANA-HIRAGANA VOICED SOUND MARK..KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK 1369..1371 ; Other_ID_Continue # No [9] ETHIOPIC DIGIT ONE..ETHIOPIC DIGIT NINE This list is available as part of the PropList.txt file in the unicode data, which ought to be included automatically in python's unicode database so as to get future changes. > My preference is to be conservative in terms of what's allowed. I do not believe it is a good idea for python to define its own identifier rules. The rules defined in UAX31 make sense and should be used directly, with only the minor amendment of _ as an allowable start character. James _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
