Method traverse

numpy/f2py/symbolic.py:659–713

Traverse expression tree with visit function. The visit function is applied to an expression with given args and kwargs. Traverse call returns an expression returned by visit when not None, otherwise return a new normalized expression with traverse-visit sub

(self, visit, *args, **kwargs)

        raise NotImplementedError(f'substitute method for {self.op}: {self!r}')

    def traverse(self, visit, *args, **kwargs):
        """Traverse expression tree with visit function.

        The visit function is applied to an expression with given args
        and kwargs.

        Traverse call returns an expression returned by visit when not
        None, otherwise return a new normalized expression with
        traverse-visit sub-expressions.
        """
        result = visit(self, *args, **kwargs)
        if result is not None:
            return result

        if self.op in (Op.INTEGER, Op.REAL, Op.STRING, Op.SYMBOL):
            return self
        elif self.op in (Op.COMPLEX, Op.ARRAY, Op.CONCAT, Op.TERNARY):
            return normalize(Expr(self.op, tuple(
                item.traverse(visit, *args, **kwargs)
                for item in self.data)))
        elif self.op in (Op.TERMS, Op.FACTORS):
            data = {}
            for k, v in self.data.items():
                k = k.traverse(visit, *args, **kwargs)
                v = (v.traverse(visit, *args, **kwargs)
                     if isinstance(v, Expr) else v)
                if k in data:
                    v = data[k] + v
                data[k] = v
            return normalize(Expr(self.op, data))
        elif self.op is Op.APPLY:
            obj = self.data[0]
            func = (obj.traverse(visit, *args, **kwargs)
                    if isinstance(obj, Expr) else obj)
            operands = tuple(operand.traverse(visit, *args, **kwargs)
                             for operand in self.data[1])
            kwoperands = {k: v.traverse(visit, *args, **kwargs)
                              for k, v in self.data[2].items()}
            return normalize(Expr(self.op, (func, operands, kwoperands)))
        elif self.op is Op.INDEXING:
            obj = self.data[0]
            obj = (obj.traverse(visit, *args, **kwargs)
                   if isinstance(obj, Expr) else obj)
            indices = tuple(index.traverse(visit, *args, **kwargs)
                            for index in self.data[1:])
            return normalize(Expr(self.op, (obj,) + indices))
        elif self.op in (Op.REF, Op.DEREF):
            return normalize(Expr(self.op,
                                  self.data.traverse(visit, *args, **kwargs)))
        elif self.op is Op.RELATIONAL:
            rop, left, right = self.data
            left = left.traverse(visit, *args, **kwargs)
            right = right.traverse(visit, *args, **kwargs)
            return normalize(Expr(self.op, (rop, left, right)))
        raise NotImplementedError(f'traverse method for {self.op}')

    def contains(self, other):
        """Check if self contains other.