Method track_visit

test/null/test_graph_rewrite.py:426–428

(ctx, x)

    """Top-down walk fires pm after children are processed (post-order)."""
    visited = []
    def track_visit(ctx, x):
      ctx.append(x.arg if x.op is Ops.CONST else x.op)
      return None
    pm = PatternMatcher([(UPat(GroupOp.All, name="x"), track_visit)])
    a = UOp.const(dtypes.int, 1)
    b = UOp.const(dtypes.int, 2)