# Functions in function
**URL:** https://discourse.julialang.org/t/functions-in-function/86958
**Category:** General Usage
**Created:** [September 8, 2022, 6:56pm UTC](https://discourse.julialang.org/t/functions-in-function/86958 "2022-09-08T18:56:23Z")
**Posts on this page:** 14
**Page:** 1
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 8, 2022, 6:56pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/1 "2022-09-08T18:56:23Z")
I have 2 functions:
```julia
f1(a1; a2=1, a3="a") # a4, a5, ...
f2(b1; b2='k', b3=2.0) # b4, b5, ...
```
I want to write a function which includes both functions and accepts all parameters of functions. What is the best way to do this? Do I have to write all the arguments of f1 and f2 in the function?
Thank you
---
### Author:  [@jbytecode](https://discourse.julialang.org/u/jbytecode)
#### Post date: [September 8, 2022, 7:12pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/2 "2022-09-08T19:12:16Z")
Something like that?
```julia
function outerfunc(a1, a2, a3, b1, b2, b3)
function f1(a1, a2 = a2, a3 = "a")
# a4 a5, ....
end
function f2(b1, b2 = b2, b3 = b3)
# b4, b5, ....
end
# possibly
# ... = f1(a1, a2 = a2, a3 = a3)
# ... = f2(b1, b2 = b2, b3 = b3)
end
```
---
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 8, 2022, 7:15pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/3 "2022-09-08T19:15:18Z")
f1 and f2 are defined outside.
Inside outerfunc I call f1 and f2.
I want outsidefunc accept parameters for f1 and f2
---
### Author:  [@jbytecode](https://discourse.julialang.org/u/jbytecode)
#### Post date: [September 8, 2022, 7:17pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/4 "2022-09-08T19:17:53Z")
Does you outer function take function names as arguments or the names of the functions are exactly defined at runtime, e.g. f1 and f2?
---
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 8, 2022, 7:53pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/5 "2022-09-08T19:53:31Z")
```julia
f1(a1; a2=1, a3="a") # a4, a5, ...
f2(b1; b2='k', b3=2.0) # b4, b5, ...
function f(x, y, z, a1, a2, a3, b1, b2, b3)
# code
f1(a1, a2=a2, a3=a3)
# code
f2(b1, b2=b2, b3=b3)
#code
end
```
It doesn’t look elegant and doesn’t scale if there are many functions.
Is there a way to take parameters for functions f1, f2 without explicitly writing them in f?
---
### Author:  [@jbytecode](https://discourse.julialang.org/u/jbytecode)
#### Post date: [September 8, 2022, 7:56pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/6 "2022-09-08T19:56:02Z")
maybe you can use three-dots like
```julia
function f(params...)
end
```
and set all of the arguments of `f1` and `f2` as optional.
---
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 8, 2022, 8:00pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/7 "2022-09-08T20:00:03Z")
f1 and f2 are in a Pkg. I didn’t write them.
I have to call them in a function but I want this function to accept the parameters for f1 and f2 as well.
---
### Author:  [@jbytecode](https://discourse.julialang.org/u/jbytecode)
#### Post date: [September 8, 2022, 8:00pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/8 "2022-09-08T20:00:57Z")
you can always wrap foreign functions
---
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 8, 2022, 8:04pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/9 "2022-09-08T20:04:44Z")
Can you give me an example?
I’d like to do something like this:
```julia
function f(x, y, z, a1, b1; params...)
# code
f1(a1; params...)
# code
f2(b1; params...)
#code
end
```
and functions choose only parameters that are compatible.
---
### Author:  [@GunnarFarneback](https://discourse.julialang.org/u/GunnarFarneback)
#### Post date: [September 8, 2022, 8:26pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/10 "2022-09-08T20:26:56Z")
That works fine if `f1` and `f2` are defined as
```julia
f1(a1; a2=1, a3="a", _...) # a4, a5, ...
f2(b1; b2='k', b3=2.0, _...) # b4, b5, ...
```
If they are defined outside your control your best bet is probably to write wrapper functions which slurp the unused keyword arguments.
---
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 8, 2022, 10:17pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/11 "2022-09-08T22:17:46Z")
This works:
```julia
# examples
f1(a1; a2=1, a3="a") = (a1, a2, a3)
f2(b1; b2='k', b3=2.0) = (b1, b2, b3)
function namedArgumentsOf(func, args...)
func_args = @which func(args...)
Base.kwarg_decl(func_args)
end
function f(a1, b1; params...)
args_f1 = [i for i in params if i[1] in namedArgumentsOf(f1, 1)]
args_f2 = [i for i in params if i[1] in namedArgumentsOf(f2, 1)]
f1(a1; args_f1...) |> println
f2(b1; args_f2...) |> println
end
f(3, 5; a2=4, a3=7, b2='e')
```
---
### Author:  [@SteffenPL](https://discourse.julialang.org/u/SteffenPL)
#### Post date: [September 8, 2022, 10:38pm UTC](https://discourse.julialang.org/t/functions-in-function/86958/12 "2022-09-08T22:38:18Z")
Nice!
A tiny detail for multiple dispatch to work, probably is should be `namedArgumentsOf(f1, a1)` (and similar for `f2`) to ensure that it uses the right method depending on the type of `a1`.
---
### Author:  [@DNF](https://discourse.julialang.org/u/DNF)
#### Post date: [September 9, 2022, 5:09am UTC](https://discourse.julialang.org/t/functions-in-function/86958/13 "2022-09-09T05:09:21Z")
I would perhaps try
```julia
function f(x, y, z, a1, b1, tup1, tup2)
f1(a1; tup1...)
f2(b1; tup2...)
end
f(x, y, a1, b1, (a2=4, a3=7), (b2='e', b3=11))
```
---
### Author:  [@qwerty](https://discourse.julialang.org/u/qwerty)
#### Post date: [September 9, 2022, 8:54am UTC](https://discourse.julialang.org/t/functions-in-function/86958/14 "2022-09-09T08:54:00Z")
I like your solution. My final code is:
```julia
f1(a1; a2=1, a3="a") = (a1, a2, a3)
f2(b1; b2='k', b3=2.0) = (b1, b2, b3)
function f(a1, b1; args_f1=(), args_f2=())
f1(a1; args_f1...) |> println
f2(b1; args_f2...) |> println
end
f(3, 5; args_f1=(a2=4, a3=7), args_f2=(b3='e',))
f(3, 5; args_f1=(a2=4, a3=7))
f(3, 5; args_f2=(b3='e',))
f(3, 5; args_f2=())
f(3, 5)
```
* * *
The only problem is:
```julia
function f(a1, b1; args_f1=(a2=3, a3="b"), args_f2=()) # If I declare args different from the default ones of f1 (or f2)
f1(a1; args_f1...) |> println
f2(b1; args_f2...) |> println
end
f(1, 2; args_f1=(a2=4,)) # I don't get a3 = "b"
f(1, 2; args_f1=(a2=4,a3="b")) # I have to write a3="b" again
```