(Embedded structs) How can i set field value for my struct at top level?

[vodish]

i try

module main

struct Test {
	Sa
	f_test  string = 'v'
	field string = 'v'
}

struct Sa {
	field string = 'v'
}


fn main() {
	mut params := Test{
		Sa: Sa{'sa'}
		f_test: 'sd1'
		field: 'sd2' // error: duplicate field name in struct literal: `field`
	}
	
	println(params)
}

[vodish]

https://play.vlang.io/p/25f404416d

[JalonSolov]

Last paragraph under https://docs.vlang.io/structs.html#embedded-structs

module main

struct Test {
        Sa
        f_test string = 'v'
        field  string = 'v'
}

struct Sa {
mut:
        field string = 'v'
}

fn main() {
        mut params := Test{
                Sa:     Sa{'sa'}
                f_test: 'sd1'
                // Sa.field: 'sd2' // error: duplicate field name in struct literal: `field`
        }
        params.Sa.field = 'sd2'

        println(params)
}

[vodish]

@JalonSolov
thanx,
but it seems strange

[JalonSolov]

You did already set it with

                Sa:     Sa{'sa'}

so there's that.

Think of it this way...

        mut params := Test{
                Sa:     Sa{'sa'} // Sa.field will be created with this value
                f_test: 'sd1'
                Sa.field: 'sd2' // at this point, `Sa` doesn't actually exist... it is created when the definition is closed on the next line
        }

Since Sa doesn't actually exist until the whole struct is created, you can't assign anything to it until after the creation.

[vodish]

 mut params := Test{
                Sa:     Sa{'sa'} // it`s ok
                f_test: 'sd1'
                field: 'sd2' // it's not obvious to me that I can't set a value for Test.field
        }

I have to do this in many steps.

mut params := Test{
                f_test: 'sd1' // for top level
                field:  'sd2' // for top level
}

params.Sa.field = 'sdcs' // for sub level

[Wajinn]

The order in which you input the values matters. Put the values for the Test struct first, then for the Sa struct (see below). Otherwise, it appears to create confusion as to which field, because they have the same names.

mut params := Test{
	f_test: 'sd1'
	field: 'sd2' // place and input values for Test struct first, then for embedded structs
	Sa: Sa{'sdcs'} // it`s ok		
}
println(params)

[vodish]

It seems the error does not reflect the essence of the problem

https://play.vlang.io/p/cf548f9443

[Wajinn]

Agree, that it might be better for the error to mention there is an embedded struct with the same field name and then offer suggestions as to the order of fields. Though, I think this issue, might be solved in other ways by the developers when they look at it.

For now, at least there is a clear workaround or way to avoid getting such an error.