nop_topdown_callback: Top-down analysis callback.
Description
Top-down analysis callback.
Usage
nop_topdown_callback(expr, topdown, skip, ...)
Arguments
expr
The expression before we modify it.
topdown
Information from further up the expression tree.
skip
An escape function. If called, the transformation
or analysis traversal will skip this expression
and continue at the sibling level.
...
Additional data that might be passed along
Value
Updated topdown information.