drasi-core 0.4.2

Drasi Core
Documentation 
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// Copyright 2024 The Drasi Authors.
//
// Licensed 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.

use async_trait::async_trait;
use drasi_query_ast::ast;

use crate::evaluation::functions::ScalarFunction;
use crate::evaluation::variable_value::float::Float;
use crate::evaluation::variable_value::VariableValue;
use crate::evaluation::{ExpressionEvaluationContext, FunctionError, FunctionEvaluationError};

#[derive(Debug)]
pub struct Abs {}

#[async_trait]
impl ScalarFunction for Abs {
    async fn call(
        &self,
        _context: &ExpressionEvaluationContext,
        expression: &ast::FunctionExpression,
        args: Vec<VariableValue>,
    ) -> Result<VariableValue, FunctionError> {
        if args.len() != 1 {
            return Err(FunctionError {
                function_name: expression.name.to_string(),
                error: FunctionEvaluationError::InvalidArgumentCount,
            });
        }
        match &args[0] {
            VariableValue::Null => Ok(VariableValue::Null),
            VariableValue::Integer(n) => Ok(VariableValue::Integer(match n.as_i64() {
                Some(i) => i.abs().into(),
                None => {
                    return Err(FunctionError {
                        function_name: expression.name.to_string(),
                        error: FunctionEvaluationError::OverflowError,
                    })
                }
            })),
            VariableValue::Float(n) => Ok(VariableValue::Float(
                match Float::from_f64(match n.as_f64() {
                    Some(f) => f.abs(),
                    None => {
                        return Err(FunctionError {
                            function_name: expression.name.to_string(),
                            error: FunctionEvaluationError::OverflowError,
                        })
                    }
                }) {
                    Some(f) => f,
                    None => {
                        return Err(FunctionError {
                            function_name: expression.name.to_string(),
                            error: FunctionEvaluationError::OverflowError,
                        })
                    }
                },
            )),
            _ => Err(FunctionError {
                function_name: expression.name.to_string(),
                error: FunctionEvaluationError::InvalidArgument(0),
            }),
        }
    }
}