drasi_core/evaluation/functions/numeric/
sign.rs

1// Copyright 2024 The Drasi Authors.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use crate::evaluation::functions::ScalarFunction;
16use crate::evaluation::variable_value::integer::Integer;
17use crate::evaluation::variable_value::VariableValue;
18use crate::evaluation::{ExpressionEvaluationContext, FunctionError, FunctionEvaluationError};
19use async_trait::async_trait;
20use drasi_query_ast::ast;
21
22#[derive(Debug)]
23pub struct Sign {}
24
25#[async_trait]
26impl ScalarFunction for Sign {
27    async fn call(
28        &self,
29        _context: &ExpressionEvaluationContext,
30        expression: &ast::FunctionExpression,
31        args: Vec<VariableValue>,
32    ) -> Result<VariableValue, FunctionError> {
33        if args.len() != 1 {
34            return Err(FunctionError {
35                function_name: expression.name.to_string(),
36                error: FunctionEvaluationError::InvalidArgumentCount,
37            });
38        }
39        match &args[0] {
40            VariableValue::Null => Ok(VariableValue::Null),
41            VariableValue::Integer(n) => {
42                let f = match n.as_i64() {
43                    Some(i) => i,
44                    None => {
45                        return Err(FunctionError {
46                            function_name: expression.name.to_string(),
47                            error: FunctionEvaluationError::OverflowError,
48                        })
49                    }
50                };
51                match f.partial_cmp(&0) {
52                    Some(std::cmp::Ordering::Greater) => {
53                        Ok(VariableValue::Integer(Integer::from(1)))
54                    }
55                    Some(std::cmp::Ordering::Less) => Ok(VariableValue::Integer(Integer::from(-1))),
56                    Some(std::cmp::Ordering::Equal) => Ok(VariableValue::Integer(Integer::from(0))),
57                    None => {
58                        return Err(FunctionError {
59                            function_name: expression.name.to_string(),
60                            error: FunctionEvaluationError::OverflowError,
61                        })
62                    }
63                }
64            }
65            VariableValue::Float(n) => {
66                let f = match n.as_f64() {
67                    Some(f) => f,
68                    None => {
69                        return Err(FunctionError {
70                            function_name: expression.name.to_string(),
71                            error: FunctionEvaluationError::OverflowError,
72                        })
73                    }
74                };
75                if f > 0.0 {
76                    Ok(VariableValue::Integer(Integer::from(1)))
77                } else if f < 0.0 {
78                    Ok(VariableValue::Integer(Integer::from(-1)))
79                } else {
80                    Ok(VariableValue::Integer(Integer::from(0)))
81                }
82            }
83            _ => Err(FunctionError {
84                function_name: expression.name.to_string(),
85                error: FunctionEvaluationError::InvalidArgument(0),
86            }),
87        }
88    }
89}
drasi_core/evaluation/functions/numeric/sign.rs

drasi_core/evaluation/functions/numeric/
sign.rs
