[Python-Dev] Recent experience with the _ast module (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Wed Feb 14 10:20:07 CET 2007

Collin Winter schrieb:

2) It turned out that {BinOp, BoolOp,AugAssign,etc}.op were already singleton instances of their respective classes. I've changed asdlc.py to no longer emit the *singleton names and to use the corresponding *type types in their place, which will enable me to write "node.op is ast.Add", etc.

I don't really like this - it's inconsistent. I'd rather prefer if the singletons where exposed under a name, e.g. _ast.Add.singleton, or _ast.add (if that doesn't cause conflicts).

3) Adding an Else node was a little more involved, but it proved do-able. TryFinally.orelse, While.orelse, For.orelse and If.orelse can now be either None or an instance of Else. Else instances have a 'body' attribute, which is a sequence of statements.

I still can't see the need (we don't have line numbers for every token in the AST), but I can't see anything wrong with it, either (except for the change in the structure, of course, but that will happen, anyway).

Regards, Martin

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