Iterating slice struct within struct using reflection

I'm trying to achieve the following:

Use-case:

• I have three structures, I need to compare 2 of those against one. (in the example described as: a & b need to be compared against full)
• Reflection is used to loop over every field, retrieve the name of the field. And comparing the difference between a & full, b & full, storing the results in a shared structure.
• If the field equals World, we know it's a slice struct:
  I need to retrieve the first index of the Bar slice within the Foo structure.
  Even though the variable is a slice, I know it will always have a length of 1 in this use-case.
  When retrieved I need to loop over those fields, like what is happening in the previous if statement.

Example code:

type Foo struct {
	Hello string
	World []Bar
}

type Bar struct {
	Fish string
}

type Result struct {
	Field string

	Correct_A  bool
	Distance_A int

	Correct_B  bool
	Distance_B int

	Result []Result
}

func compare_structs() {
	var full, a, b Foo

	// filling in all variables...

	result := []Result{}

	rfx_f := reflect.ValueOf(full)
	rfx_a := reflect.ValueOf(a)
	rfx_b := reflect.ValueOf(b)

	type_result := rfx_f.Type()

	for i := 0; i < rfx_f.NumField(); i++ {
		tmp_res := Result{
			Field: type_result.Field(i).Name,
		}

		if reflect.TypeOf(full).Field(i).Type.Kind() != reflect.Slice {
			value := rfx_f.Field(i).Interface()
			value_a := rfx_a.FieldByName(tmp_res.Field).Interface()
			value_b := rfx_b.FieldByName(tmp_res.Field).Interface()

			// functions to compare the values of this field
			tmp_res.compare(value, value_a, value_b)
			tmp_res.lev(value, value_a, value_b)

			result = append(result, tmp_res)
		} else if tmp_res.Field == "World" {
			/*
				I need to retrieve the first index of the Bar slice within the Foo structure.
				Even though the variable is a slice, I know it will always have a length of 1 in this use-case.
				When retrieved I need to loop over those fields, like what is happening in the previous if statement.
			*/
		}

	}
}

You first need to get the field:

wordField:=rfx_f.Field(i)

which you know to be a slice, so you index it to get the first element

item:=wordField.Index(0)

This will panic if index is out of range.

Then you can iterate the fields:

for fieldIx:=0;fieldIx<item.NumField();fieldIx++ {
field:=item.Field(fieldIx)
}