| // Copyright 2018 The CUE 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. |
| |
| package list |
| |
| import ( |
| "fmt" |
| |
| "cuelang.org/go/internal" |
| "github.com/cockroachdb/apd/v2" |
| ) |
| |
| // Avg returns the average value of a non empty list xs. |
| func Avg(xs []*internal.Decimal) (*internal.Decimal, error) { |
| if 0 == len(xs) { |
| return nil, fmt.Errorf("empty list") |
| } |
| |
| s := apd.New(0, 0) |
| for _, x := range xs { |
| _, err := internal.BaseContext.Add(s, x, s) |
| if err != nil { |
| return nil, err |
| } |
| } |
| |
| var d apd.Decimal |
| l := apd.New(int64(len(xs)), 0) |
| _, err := internal.BaseContext.Quo(&d, s, l) |
| if err != nil { |
| return nil, err |
| } |
| return &d, nil |
| } |
| |
| // Max returns the maximum value of a non empty list xs. |
| func Max(xs []*internal.Decimal) (*internal.Decimal, error) { |
| if 0 == len(xs) { |
| return nil, fmt.Errorf("empty list") |
| } |
| |
| max := xs[0] |
| for _, x := range xs[1:] { |
| if -1 == max.Cmp(x) { |
| max = x |
| } |
| } |
| return max, nil |
| } |
| |
| // Min returns the minimum value of a non empty list xs. |
| func Min(xs []*internal.Decimal) (*internal.Decimal, error) { |
| if 0 == len(xs) { |
| return nil, fmt.Errorf("empty list") |
| } |
| |
| min := xs[0] |
| for _, x := range xs[1:] { |
| if +1 == min.Cmp(x) { |
| min = x |
| } |
| } |
| return min, nil |
| } |
| |
| // Product returns the product of a non empty list xs. |
| func Product(xs []*internal.Decimal) (*internal.Decimal, error) { |
| d := apd.New(1, 0) |
| for _, x := range xs { |
| _, err := internal.BaseContext.Mul(d, x, d) |
| if err != nil { |
| return nil, err |
| } |
| } |
| return d, nil |
| } |
| |
| // Sum returns the sum of a list non empty xs. |
| func Sum(xs []*internal.Decimal) (*internal.Decimal, error) { |
| d := apd.New(0, 0) |
| for _, x := range xs { |
| _, err := internal.BaseContext.Add(d, x, d) |
| if err != nil { |
| return nil, err |
| } |
| } |
| return d, nil |
| } |