85 lines
2.4 KiB
Go
85 lines
2.4 KiB
Go
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package lo
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import "golang.org/x/exp/constraints"
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// Range creates an array of numbers (positive and/or negative) with given length.
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// Play: https://go.dev/play/p/0r6VimXAi9H
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func Range(elementNum int) []int {
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length := If(elementNum < 0, -elementNum).Else(elementNum)
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result := make([]int, length)
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step := If(elementNum < 0, -1).Else(1)
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for i, j := 0, 0; i < length; i, j = i+1, j+step {
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result[i] = j
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}
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return result
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}
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// RangeFrom creates an array of numbers from start with specified length.
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// Play: https://go.dev/play/p/0r6VimXAi9H
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func RangeFrom[T constraints.Integer | constraints.Float](start T, elementNum int) []T {
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length := If(elementNum < 0, -elementNum).Else(elementNum)
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result := make([]T, length)
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step := If(elementNum < 0, -1).Else(1)
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for i, j := 0, start; i < length; i, j = i+1, j+T(step) {
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result[i] = j
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}
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return result
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}
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// RangeWithSteps creates an array of numbers (positive and/or negative) progressing from start up to, but not including end.
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// step set to zero will return empty array.
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// Play: https://go.dev/play/p/0r6VimXAi9H
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func RangeWithSteps[T constraints.Integer | constraints.Float](start, end, step T) []T {
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result := []T{}
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if start == end || step == 0 {
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return result
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}
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if start < end {
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if step < 0 {
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return result
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}
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for i := start; i < end; i += step {
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result = append(result, i)
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}
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return result
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}
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if step > 0 {
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return result
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}
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for i := start; i > end; i += step {
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result = append(result, i)
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}
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return result
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}
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// Clamp clamps number within the inclusive lower and upper bounds.
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// Play: https://go.dev/play/p/RU4lJNC2hlI
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func Clamp[T constraints.Ordered](value T, min T, max T) T {
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if value < min {
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return min
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} else if value > max {
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return max
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}
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return value
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}
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// Sum sums the values in a collection. If collection is empty 0 is returned.
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// Play: https://go.dev/play/p/upfeJVqs4Bt
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func Sum[T constraints.Float | constraints.Integer | constraints.Complex](collection []T) T {
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var sum T = 0
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for _, val := range collection {
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sum += val
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}
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return sum
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}
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// SumBy summarizes the values in a collection using the given return value from the iteration function. If collection is empty 0 is returned.
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// Play: https://go.dev/play/p/Dz_a_7jN_ca
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func SumBy[T any, R constraints.Float | constraints.Integer | constraints.Complex](collection []T, iteratee func(item T) R) R {
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var sum R = 0
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for _, item := range collection {
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sum = sum + iteratee(item)
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}
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return sum
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}
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