static

README

static

Static function variables for Go without global var guilt.

Example

package main

import (
	"fmt"

	"codeberg.org/yarmak/static"
)

func counter1() int {
	st := static.State[int]()
	(*st)++
	return (*st)
}

func counter2() int {
	st := static.State[int]()
	(*st)++
	return (*st)
}

func complex(key string) int {
	st := static.State1(func() map[string]int { return make(map[string]int) })
	m := *st
	m[key]++
	return m[key]
}

func multi(a, b, c int) (int, int, int) {
	st := static.State[struct{ a, b, c int }]()
	st.a += a
	st.b += b
	st.c += c
	return st.a, st.b, st.c
}

func main() {
	fmt.Println("counter1:")
	fmt.Println(counter1())
	fmt.Println(counter1())
	fmt.Println(counter1())
	fmt.Println("counter2:")
	fmt.Println(counter2())
	fmt.Println(counter2())
	fmt.Println("complex state:")
	fmt.Println(complex("a"))
	fmt.Println(complex("b"))
	fmt.Println(complex("c"))
	fmt.Println(complex("a"))
	fmt.Println(complex("a"))
	fmt.Println("anon func:")
	f := func() int {
		st := static.State[int]()
		(*st)++
		return (*st)
	}
	fmt.Println(f())
	fmt.Println(f())
	fmt.Println(f())
	fmt.Println("multi:")
	fmt.Println(multi(0, 0, 0))
	fmt.Println(multi(1, 2, 3))
	fmt.Println(multi(10, 10, 10))
}

Output:

counter1:
1
2
3
counter2:
1
2
complex state:
1
1
1
2
3
anon func:
1
2
3
multi:
0 0 0
1 2 3
11 12 13

Documentation

Overview

Package static introduces static variables for functions, encapsulating all the global var guilt within this module.

Methods of this package are safe for concurrent use, but the access to returned pointers may need to be serialized for concurrent use (e.g. by a mutex within that state).

Same type parameter must be used for State calls within one function.

Index

• func State[T any]() *T
• func State1[T any](init func() T) (ptr *T)

Functions

func State

func State[T any]() *T

State is a shorthand for State1(nil)

func State1

func State1[T any](init func() T) (ptr *T)

State1 returns function state pointer initializing new ones with value from init function if it is not nil