Top-down analysis callback.
nop_topdown_callback(expr, topdown, skip, ...)
| 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 |
Updated topdown information.