1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// 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
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

//! Not expression

use std::any::Any;
use std::fmt;
use std::hash::{Hash, Hasher};
use std::sync::Arc;

use crate::physical_expr::down_cast_any_ref;
use crate::PhysicalExpr;
use arrow::datatypes::{DataType, Schema};
use arrow::record_batch::RecordBatch;
use datafusion_common::{cast::as_boolean_array, Result, ScalarValue};
use datafusion_expr::ColumnarValue;

/// Not expression
#[derive(Debug, Hash)]
pub struct NotExpr {
    /// Input expression
    arg: Arc<dyn PhysicalExpr>,
}

impl NotExpr {
    /// Create new not expression
    pub fn new(arg: Arc<dyn PhysicalExpr>) -> Self {
        Self { arg }
    }

    /// Get the input expression
    pub fn arg(&self) -> &Arc<dyn PhysicalExpr> {
        &self.arg
    }
}

impl fmt::Display for NotExpr {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "NOT {}", self.arg)
    }
}

impl PhysicalExpr for NotExpr {
    /// Return a reference to Any that can be used for downcasting
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn data_type(&self, _input_schema: &Schema) -> Result<DataType> {
        Ok(DataType::Boolean)
    }

    fn nullable(&self, input_schema: &Schema) -> Result<bool> {
        self.arg.nullable(input_schema)
    }

    fn evaluate(&self, batch: &RecordBatch) -> Result<ColumnarValue> {
        let evaluate_arg = self.arg.evaluate(batch)?;
        match evaluate_arg {
            ColumnarValue::Array(array) => {
                let array = as_boolean_array(&array)?;
                Ok(ColumnarValue::Array(Arc::new(
                    arrow::compute::kernels::boolean::not(array)?,
                )))
            }
            ColumnarValue::Scalar(scalar) => {
                if scalar.is_null() {
                    return Ok(ColumnarValue::Scalar(ScalarValue::Boolean(None)));
                }
                let bool_value: bool = scalar.try_into()?;
                Ok(ColumnarValue::Scalar(ScalarValue::Boolean(Some(
                    !bool_value,
                ))))
            }
        }
    }

    fn children(&self) -> Vec<Arc<dyn PhysicalExpr>> {
        vec![self.arg.clone()]
    }

    fn with_new_children(
        self: Arc<Self>,
        children: Vec<Arc<dyn PhysicalExpr>>,
    ) -> Result<Arc<dyn PhysicalExpr>> {
        Ok(Arc::new(NotExpr::new(children[0].clone())))
    }

    fn dyn_hash(&self, state: &mut dyn Hasher) {
        let mut s = state;
        self.hash(&mut s);
    }
}

impl PartialEq<dyn Any> for NotExpr {
    fn eq(&self, other: &dyn Any) -> bool {
        down_cast_any_ref(other)
            .downcast_ref::<Self>()
            .map(|x| self.arg.eq(&x.arg))
            .unwrap_or(false)
    }
}

/// Creates a unary expression NOT
pub fn not(arg: Arc<dyn PhysicalExpr>) -> Result<Arc<dyn PhysicalExpr>> {
    Ok(Arc::new(NotExpr::new(arg)))
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::expressions::col;
    use arrow::{array::BooleanArray, datatypes::*};
    use datafusion_common::Result;

    #[test]
    fn neg_op() -> Result<()> {
        let schema = Schema::new(vec![Field::new("a", DataType::Boolean, true)]);

        let expr = not(col("a", &schema)?)?;
        assert_eq!(expr.data_type(&schema)?, DataType::Boolean);
        assert!(expr.nullable(&schema)?);

        let input = BooleanArray::from(vec![Some(true), None, Some(false)]);
        let expected = &BooleanArray::from(vec![Some(false), None, Some(true)]);

        let batch =
            RecordBatch::try_new(Arc::new(schema.clone()), vec![Arc::new(input)])?;

        let result = expr
            .evaluate(&batch)?
            .into_array(batch.num_rows())
            .expect("Failed to convert to array");
        let result =
            as_boolean_array(&result).expect("failed to downcast to BooleanArray");
        assert_eq!(result, expected);

        Ok(())
    }
}