在Genie中嵌套泛型类型的语法是什么?

Question

我想声明一个HasTable，其中string为键，array of int为值:

[indent=4]
init
    var h = new HashTable of string, array of int (str_hash, str_equal)
    h["a"] = {1, 2, 3}
    h["b"] = {5, 6, 7}

错误信息:

nested_generic_types.gs:4.27-4.28: error: syntax error, expected line end or semicolon but got `of'
    var h = new HashTable of string, array of int (str_hash, str_equal)

所以双of在这里似乎混淆了valac。

正确的语法是什么?

Answer 1

错误信息与vala不同。

Genie的错误消息看起来像编译器的解析问题。Vala的错误信息更清晰。

my test in vala:

void main () {
    var h = new HashTable<string, int[]> (str_hash, str_equal);
}

错误信息:

error: `int[]' is not a supported generic type argument, 
use `?' to box value types

看起来就是不支持"array"，其他的都可以。'array'不能是任何容器(HashTable, array, GenericArray, array..)中的元素

some test: all works!

[indent=4]
init
    var h = new HashTable of string, HashTable of string, int (str_hash, str_equal)
    h["a"] = new HashTable of string, int (str_hash, str_equal)
    h["a"]["b"] = 123
    stdout.printf ("%dn", h["a"]["b"])
    var a = new HashTable of string, Array of int (str_hash, str_equal)
    a["a"] = new Array of int
    // a["a"].append_val (456)
    // error: lvalue expected
    var x = 456
    a["a"].append_val (x)
    stdout.printf ("%dn", a["a"].index(0))

    var b = new HashTable of string, GenericArray of int (str_hash, str_equal)
    b["a"] = new GenericArray of int
    b["a"].add (567)
    stdout.printf ("%dn", b["a"].get (0))
    var d = new array of Array of int = {new Array of int(), new Array of int}
    // ERROR IF {new Array of int, new Array of int}
    var y = 321
    d[0].append_val (y)
    stdout.printf ("%dn", d[0].index(0))

来自:http://blog.gmane.org/gmane.comp.programming.vala/month=20140701

没有正确的语法，它只是不支持。