mapsutil

Documentation

Overview

Package mapsutil contains utilities for map handling.

Index

• func SortedRange[K constraints.Ordered, V any, M ~map[K]V](m M, f func(k K, v V) (cont bool))
• func SortedRangeError[K constraints.Ordered, V any, M ~map[K]V](m M, f func(k K, v V) (err error)) (err error)

Examples

• SortedRange
• SortedRangeError

Functions

func SortedRange

func SortedRange[K constraints.Ordered, V any, M ~map[K]V](m M, f func(k K, v V) (cont bool))

SortedRange is like the usual Go range but sorts the keys before iterating ensuring a predictable order. If cont is false, SortedRange stops the iteration.

Example

package main

import (
	"fmt"

	"github.com/AdguardTeam/golibs/mapsutil"
)

func main() {
	m := map[string]int{
		"b": 200,
		"a": 100,
		"c": 300,
		"d": 400,
	}

	mapsutil.SortedRange(m, func(k string, v int) (cont bool) {
		fmt.Printf("value for %q is %d\n", k, v)

		// Do not print any values after "c".
		return k != "c"
	})

}

Output:

value for "a" is 100
value for "b" is 200
value for "c" is 300

func SortedRangeError

func SortedRangeError[K constraints.Ordered, V any, M ~map[K]V](
	m M,
	f func(k K, v V) (err error),
) (err error)

SortedRangeError is like SortedRange but uses an error to signal that the iteration must be stopped. err is the same error as the one returned from f, or nil if no errors are returned.

Example

package main

import (
	"fmt"

	"github.com/AdguardTeam/golibs/mapsutil"
)

func main() {
	checkKey := func(k string, v int) (err error) {
		if k == "x" {
			return fmt.Errorf("bad key: %q", k)
		}

		fmt.Printf("value for %q is %d\n", k, v)

		return nil
	}

	err := mapsutil.SortedRangeError(
		map[string]int{
			"b": 200,
			"a": 100,
			"c": 300,
		},
		checkKey,
	)

	fmt.Println(err)

	err = mapsutil.SortedRangeError(
		map[string]int{
			"x": 0,
		},
		checkKey,
	)

	fmt.Println(err)

}

Output:

value for "a" is 100
value for "b" is 200
value for "c" is 300
<nil>
bad key: "x"