golang uses functools.partial or similar methods to complete wrapping other functions

Question content

（golang newbie）

Suppose I have two functions that interact with the underlying api, and I want to wrap these two functions with retry, but the two functions have different input parameters.

In python I would use functools.partial to create a partial func object and pass it to

from functools import partial

def api_1(a, b, c):
  print(a, b, c)
  return true
  
def api_2(x, y):
  print(x, y)
  return true

def with_retries(func) {
  retries = 0
  while retries < 3:
    err = func()
    if not err:
      break
    retries += 1
}

def main():
  with_retries(partial(api_1, 1, 2, 3))
  with_retries(partial(api_2, 'x', 'y'))

Using the simple example above, how can I do something similar in golang? I looked at the functools.partial package function but that function doesn't seem to allow passing all arguments when creating a partial function?

Is there a completely different pattern in golang to accomplish this retry pattern?

Correct answer

If I understand correctly functools.partial, it allows you to curry functions.

In go, you can use closures to curry functions:

func add(x,y int) int {
  return x+y
}
// curries add to yield a function that adds 4
func add4(y int) int {
  return add(4,y)
}

go supports first-class functions, so you can pass functions as variables. In this example, we create a function do that accepts (a) any int-->int function and (b) int and returns The result of this function applied to int:

func do(f func(int) int, y int) int {
    return f(y)
}

Also, since do only requires int-->int we can use e.g. neg also as follows:

package main

import "fmt"

func Add(x, y int) int {
    return x + y
}
func Add4(y int) int {
    return Add(4, y)
}

func Neg(x int) int {
    return -x
}

func Do(f func(int) int, y int) int {
    return f(y)
}
func main() {
    fmt.Println(Add4(6))
    fmt.Println(Do(Add4, 6))
    fmt.Println(Do(Neg, 6))
}

See: https://www.php.cn/link/7a43ed4e82d06a1e6b2e88518fb8c2b0 p>

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