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package gotil |
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// FindBy iterates over elements of collection, returns an object of fist element predicate if returns true for. |
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// data := []int64{-100, -5, 30, 100} |
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// newData, _ := FindBy(data, func(val interface{}, i int) bool { |
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// if val.(int64) == 30 { |
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// return true |
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// } else { |
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// return false |
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// } |
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// }) |
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// // Output: 30 |
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func FindBy[T any](s []T, f func(val T) bool) T { |
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return FindByFromIndex(s, f, 0) |
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} |
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// FindByFromIndex iterates over elements of collection, returns an object of fist element predicate if returns true for. |
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// It works same as FindBy just from parameter provides to set start index of given slice or array. |
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func FindByFromIndex[T any](s []T, f func(val T) bool, from int) T { |
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var result T |
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index := findIndex(s, f, 0) |
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if index > -1 { |
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return s[index] |
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} |
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return result |
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} |
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// FindLastBy iterates over elements of collection, returns an object of lastest element predicate if returns true for. |
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// data := []int64{-100, -5, 30, 100} |
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// newData, _ := FindLastBy(data, func(val interface{}, i int) bool { |
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// if val.(int64) == 30 { |
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// return true |
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// } else { |
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// return false |
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// } |
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// }) |
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// // Output: 30 |
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func FindLastBy[T any](s []T, f func(val T) bool) T { |
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return FindLastByFromIndex(s, f, 0) |
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} |
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// FindLastBy iterates over elements of collection, returns an object of lastest element predicate if returns true for. |
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// It works same as FindLastBy just from parameter provides to set start index of given slice or array. |
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func FindLastByFromIndex[T any](s []T, f func(val T) bool, from int) T { |
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var result T |
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index := findLastIndex(s, f, 0) |
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if index > -1 { |
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return s[index] |
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} |
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return result |
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} |
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func findIndex[T any](s []T, f func(val T) bool, from int) int { |
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length := len(s) |
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if length == 0 { |
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return -1 |
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} |
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index := 0 |
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if from < 0 { |
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index = max(length+index, 0) |
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} else { |
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index = min(index, length-1) |
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} |
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return baseFindIndex(s, f, index, false) |
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} |
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func findLastIndex[T any](s []T, f func(val T) bool, from int) int { |
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length := len(s) |
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if length == 0 { |
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return -1 |
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} |
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index := length - 1 |
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if from < 0 { |
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index = max(length+index, 0) |
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} else { |
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index = min(index, length-1) |
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} |
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return baseFindIndex(s, f, index, true) |
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} |
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func baseFindIndex[T any](s []T, f func(val T) bool, from int, right bool) int { |
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length := len(s) |
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index := from |
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if right { |
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for index < length { |
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value := s[index] |
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if f(value) { |
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return index |
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} |
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index-- |
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} |
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} else { |
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for index < length { |
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value := s[index] |
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if f(value) { |
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return index |
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} |
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index++ |
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} |
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} |
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return -1 |
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} |
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func max(a, b int) int { |
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if a > b { |
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return a |
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} |
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return b |
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} |
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func min(a, b int) int { |
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if a < b { |
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return a |
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} |
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return b |
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} |
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gotilty /
gotil
