github.com/mymmsc/gox@v1.3.33/util/examples/enumerablewithindex/enumerablewithindex.go (about)

     1  // Copyright (c) 2015, Emir Pasic. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"fmt"
     9  	"github.com/mymmsc/gox/util/treeset"
    10  )
    11  
    12  func printSet(txt string, set *treeset.Set) {
    13  	fmt.Print(txt, "[ ")
    14  	set.Each(func(index int, value interface{}) {
    15  		fmt.Print(value, " ")
    16  	})
    17  	fmt.Println("]")
    18  }
    19  
    20  // EnumerableWithIndexExample to demonstrate basic usage of EnumerableWithIndex
    21  func main() {
    22  	set := treeset.NewWithIntComparator()
    23  	set.Add(2, 3, 4, 2, 5, 6, 7, 8)
    24  	printSet("Initial", set) // [ 2 3 4 5 6 7 8 ]
    25  
    26  	even := set.Select(func(index int, value interface{}) bool {
    27  		return value.(int)%2 == 0
    28  	})
    29  	printSet("Even numbers", even) // [ 2 4 6 8 ]
    30  
    31  	foundIndex, foundValue := set.Find(func(index int, value interface{}) bool {
    32  		return value.(int)%2 == 0 && value.(int)%3 == 0
    33  	})
    34  	if foundIndex != -1 {
    35  		fmt.Println("Number divisible by 2 and 3 found is", foundValue, "at index", foundIndex) // value: 6, index: 4
    36  	}
    37  
    38  	square := set.Map(func(index int, value interface{}) interface{} {
    39  		return value.(int) * value.(int)
    40  	})
    41  	printSet("Numbers squared", square) // [ 4 9 16 25 36 49 64 ]
    42  
    43  	bigger := set.Any(func(index int, value interface{}) bool {
    44  		return value.(int) > 5
    45  	})
    46  	fmt.Println("Set contains a number bigger than 5 is ", bigger) // true
    47  
    48  	positive := set.All(func(index int, value interface{}) bool {
    49  		return value.(int) > 0
    50  	})
    51  	fmt.Println("All numbers are positive is", positive) // true
    52  
    53  	evenNumbersSquared := set.Select(func(index int, value interface{}) bool {
    54  		return value.(int)%2 == 0
    55  	}).Map(func(index int, value interface{}) interface{} {
    56  		return value.(int) * value.(int)
    57  	})
    58  	printSet("Chaining", evenNumbersSquared) // [ 4 16 36 64 ]
    59  }