genie HashTable of string, STRUCT - hashtable

Question

NOTE: my question is array, not [ Array or GenericArray ]
this is my code:
init
var h = new HashTable of string, Int? (str_hash, str_equal)
h["a"] = Int ({1, 2, 3})
h["b"] = Int ({5, 6, 7}) // HERE: WORKS FINE
// ERROR HERE:
// Array concatenation not supported for public array variables and parameters
h["a"].data += 4
struct Int
data: array of int
construct (a: array of int)
this.data = a
how to fix this?

Answer 1

Not really an answer, but an alternative way to express this:
init
var h = new HashTable of string, Int? (str_hash, str_equal)
h["a"] = Int ({1, 2, 3})
h["b"] = Int ({5, 6, 7})
h["a"].append ({4})
struct Int
data: array of int
construct (a: array of int)
this.data = a
def append (a: array of int)
this.data = this.data + a
Now there is no mixing of "variables and parameters" going on anymore, which solves the compiler error your original code is triggering.
The problem is that this also results in a compiler error:
resize_array.gs:14.21-14.33: error: Incompatible operand
this.data = this.data + a
Which can be simplified to this code:
init
x: array of int = {1, 2, 3}
y: array of int = {4, 5, 6}
z: array of int = x + y
Which also produces the same compiler error.
resize_array.gs:21.23-21.27: error: Incompatible operand
z: array of int = x + y
I have added a new question based on this:
How to concatenate two arrays?
As it turns out concating arrays (it works for string though!) is not a trivial task in Vala/Genie.
See the other question for solutions on how to do this.
I'd personally use Gee containers for this (if I don't have to frequently call some C functions that need a plain array).
The solution using Array of int:
init
var h = new HashTable of string, Int? (str_hash, str_equal)
h["a"] = Int ({1, 2, 3})
h["b"] = Int ({5, 6, 7})
h["a"].append ({4})
struct Int
data: Array of int
construct (a: array of int)
data = new Array of int;
append (a)
def append (a: array of int)
data.append_vals (a, a.length)

Answer 2

A bug of Genie? maybe?
I try that in Vala, Works fine.
The output:
1, 2, 3, 4, 55, 666,
struct Int {
int[] data;
Int(int[] a){
this.data = a;
}
}
void main(){
var h = new HashTable<string, Int?> (str_hash, str_equal);
h["a"] = Int({1, 2, 3});
h["b"] = Int({4, 5, 6});
h["a"].data += 4;
h["a"].data += 55;
h["a"].data += 666;
for (var i = 0; i < h["a"].data.length; i++) {
stdout.printf("%d, ", h["a"].data[i]);
}
}