computeIfAbsentString

Description:

public static string computeIfAbsentString (HashMap<string,string> map, string key, owned SupplierFunc<string> fn)

Returns the value for the key. If the key is absent, computes the value using the supplier function, stores it in the map, and returns it.

Note:

this method modifies the original map when the key is absent.

Example:

    var cache = new HashMap<string, string> (GLib.str_hash, GLib.str_equal);
    var val = Maps.computeIfAbsentString (cache, "key", () => {
        return "computed";
    });
    // val == "computed", cache["key"] == "computed"

Parameters:

map	the map to query and potentially update.
key	the key to look up.
fn	the supplier function to compute the value if absent.

Returns:

the existing or newly computed value.