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// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
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//! SQL planning extensions like [`UnicodeFunctionPlanner`]

use datafusion_expr::Expr;
use datafusion_expr::expr::ScalarFunction;
use datafusion_expr::planner::{ExprPlanner, PlannerResult};

#[derive(Default, Debug)]
pub struct UnicodeFunctionPlanner;

impl ExprPlanner for UnicodeFunctionPlanner {
    fn plan_position(
        &self,
        args: Vec<Expr>,
    ) -> datafusion_common::Result<PlannerResult<Vec<Expr>>> {
        Ok(PlannerResult::Planned(Expr::ScalarFunction(
            ScalarFunction::new_udf(crate::unicode::strpos(), args),
        )))
    }

    fn plan_substring(
        &self,
        args: Vec<Expr>,
    ) -> datafusion_common::Result<PlannerResult<Vec<Expr>>> {
        Ok(PlannerResult::Planned(Expr::ScalarFunction(
            ScalarFunction::new_udf(crate::unicode::substr(), args),
        )))
    }
}
