forked from pingcap/tidb
/
builtin_math.go
45 lines (39 loc) · 1.27 KB
/
builtin_math.go
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// Copyright 2015 PingCAP, Inc.
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package expressions
import (
"math"
"github.com/pingcap/tidb/util/types"
)
// see https://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html
func builtinAbs(args []interface{}, ctx map[interface{}]interface{}) (v interface{}, err error) {
switch x := args[0].(type) {
case nil:
return nil, nil
case uint, uint8, uint16, uint32, uint64:
return x, nil
case int, int8, int16, int32, int64:
// we don't need to handle error here, it must be success
v, _ := types.ToInt64(args[0])
if v >= 0 {
return x, nil
}
// TODO: handle overflow if x is MinInt64
return -v, nil
default:
// we will try to convert other types to float
// TODO: if time has no precision, it will be a integer
f, err := types.ToFloat64(args[0])
return math.Abs(f), err
}
}