Documentation
¶
Overview ¶
Package reducer provides a few often used Reducers for iterator.Reduce
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Count ¶ added in v0.0.4
Count increases acc on each call, effectively counting the number of inputs.
Example ¶
package main
import (
"fmt"
"github.com/KrischanCS/go-toolbox/iterator"
"github.com/KrischanCS/go-toolbox/iterator/reducer"
)
func main() {
i := iterator.Of("a,", "b", "c", "d", "e")
count := 0
iterator.Reduce(i, &count, reducer.Count)
fmt.Println(count)
}
Output: 5
func GroupBy ¶
func GroupBy[KEY comparable, IN any](keyFunc func(IN) KEY) iterator.Reducer[map[KEY][]IN, IN]
GroupBy creates a iterator.Reducer which groups the given inputs by the result of the given keyFunc.
Example ¶
package main
import (
"fmt"
"github.com/KrischanCS/go-toolbox/iterator"
"github.com/KrischanCS/go-toolbox/iterator/reducer"
)
func main() {
type person struct {
name string
age int
}
persons := iterator.Of(
person{"Alice", 30},
person{"Bob", 2},
person{"Charlie", 13},
person{"Dory", 25},
person{"Edward", 8},
person{"Fiona", 2},
person{"Greg", 5},
)
keyFunc := func(p person) string {
switch {
case p.age < 3:
return "toddler"
case p.age < 13:
return "child"
case p.age < 18:
return "teen"
default:
return "adult"
}
}
groups := make(map[string][]person)
iterator.Reduce(persons, &groups, reducer.GroupBy(keyFunc))
// Print results in a deterministic order
for _, category := range []string{"toddler", "child", "teen", "adult"} {
if people, exists := groups[category]; exists {
fmt.Printf("%s: %+v\n", category, people)
}
}
}
Output: toddler: [{name:Bob age:2} {name:Fiona age:2}] child: [{name:Edward age:8} {name:Greg age:5}] teen: [{name:Charlie age:13}] adult: [{name:Alice age:30} {name:Dory age:25}]
func Join ¶
Join creates a iterator.Reducer which joins all given strings with the given separator.
Example ¶
package main
import (
"fmt"
"strings"
"github.com/KrischanCS/go-toolbox/iterator"
"github.com/KrischanCS/go-toolbox/iterator/reducer"
)
func main() {
i := iterator.Of("a", "b", "c")
var sb strings.Builder
iterator.Reduce(i, &sb, reducer.Join(", "))
fmt.Println(sb.String())
}
Output: a, b, c
func Product ¶
func Product[T constraints.RealNumber](acc *T, in T)
Product multiplies acc by input.
Example ¶
package main
import (
"fmt"
"github.com/KrischanCS/go-toolbox/iterator"
"github.com/KrischanCS/go-toolbox/iterator/reducer"
)
func main() {
i := iterator.Of(3, 4)
product := 1
iterator.Reduce(i, &product, reducer.Product)
fmt.Println(product)
}
Output: 12
func Sum ¶
func Sum[T constraints.RealNumber](acc *T, in T)
Sum adds the given value to acc.
Example ¶
package main
import (
"fmt"
"github.com/KrischanCS/go-toolbox/iterator"
"github.com/KrischanCS/go-toolbox/iterator/reducer"
)
func main() {
i := iterator.Of(1, 2, 3, 4, 5)
sum := 0
iterator.Reduce(i, &sum, reducer.Sum)
fmt.Println(sum)
}
Output: 15
Types ¶
This section is empty.
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
|
Package statistics provides reducers for gathering statistics from an iterator.
|
Package statistics provides reducers for gathering statistics from an iterator. |
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