SF patch #1015989
The basic idea of this patch is to compute lineno attributes for all AST nodes. The actual
implementation lead to a lot of restructing and code cleanup.
The generated AST nodes now have an optional lineno argument to constructor. Remove the
top-level asList(), since it didn't seem to serve any purpose. Add an __iter__ to ast nodes.
Use isinstance() instead of explicit type tests.
Change transformer to use the new lineno attribute, which replaces three lines of code with one.
Use universal newlines so that we can get rid of special-case code for line endings. Use
lookup_node() in a few more frequently called, but simple com_xxx methods(). Change string
exception to class exception.
The argument properties are ordered from easiest to hardest. The
harder the arg, the more complicated that code that must be generated
to return it from getChildren() and/or getChildNodes(). The old
calculation routine was bogus, because it always set hardest_arg to
the hardness of the last argument. Now use max() to always set it to
the hardness of the hardest argument.
Add support for floor division (// and //=)
The implementation of getChildren() and getChildNodes() is intended to
be faster, because it avoids calling flatten() on every return value.
But it's not clear that it is a lot faster, because constructing a
tuple with just the right values ends up being slow. (Too many
attribute lookups probably.)
The ast.txt file is much more complicated, with funny characters at
the ends of names (*, &, !) to indicate the types of each child node.
The astgen script is also much more complex, making me wonder if it's
still useful.