Creates a new #GVariantType corresponding to the type string given by type_string. It is appropriate to call glib.variant_type.VariantType.free on the return value.
Makes a copy of a #GVariantType. It is appropriate to call glib.variant_type.VariantType.free on the return value. type may not be null.
Returns a newly-allocated copy of the type string corresponding to type. The returned string is nul-terminated. It is appropriate to call glib.global.gfree on the return value.
Determines the element type of an array or maybe type.
Compares type1 and type2 for equality.
Determines the first item type of a tuple or dictionary entry type.
Returns the length of the type string corresponding to the given type. This function must be used to determine the valid extent of the memory region returned by glib.variant_type.VariantType.peekString.
Hashes type.
Determines if the given type is an array type. This is true if the type string for type starts with an 'a'.
Determines if the given type is a basic type.
Determines if the given type is a container type.
Determines if the given type is definite (ie: not indefinite).
Determines if the given type is a dictionary entry type. This is true if the type string for type starts with a '{'.
Determines if the given type is a maybe type. This is true if the type string for type starts with an 'm'.
Checks if type is a subtype of supertype.
Determines if the given type is a tuple type. This is true if the type string for type starts with a '(' or if type is G_VARIANT_TYPE_TUPLE.
Determines if the given type is the variant type.
Determines the key type of a dictionary entry type.
Determines the number of items contained in a tuple or dictionary entry type.
Determines the next item type of a tuple or dictionary entry type.
Determines the value type of a dictionary entry type.
Template for creating a new VariantType from one or more D types
Template to get a variant type string from one or more D types (type strings are concatenated)
Constructs the type corresponding to an array of elements of the type type.
Constructs the type corresponding to a dictionary entry with a key of type key and a value of type value.
Constructs the type corresponding to a maybe instance containing type type or Nothing.
Constructs a new tuple type, from items.
Checks if type_string is a valid GVariant type string. This call is equivalent to calling glib.variant_type.VariantType.stringScan and confirming that the following character is a nul terminator.
Scan for a single complete and valid GVariant type string in string. The memory pointed to by limit (or bytes beyond it) is never accessed.
Pointer to the C boxed value
Get the GType of this boxed type.
Boxed GType property.
Convenience method to return this cast to a type. For use in D with statements.
Make a copy of the wrapped C boxed data.
Copy a C boxed value using g_boxed_copy.
Free a C boxed value using g_boxed_free.
A type in the glib.variant.VariantG type system.
This section introduces the glib.variant.VariantG type system. It is based, in large part, on the D-Bus type system, with two major changes and some minor lifting of restrictions. The D-Bus specification, therefore, provides a significant amount of information that is useful when working with glib.variant.VariantG.
The first major change with respect to the D-Bus type system is the introduction of maybe (or ‘nullable’) types. Any type in glib.variant.VariantG can be converted to a maybe type, in which case, nothing (or null) becomes a valid value. Maybe types have been added by introducing the character m to type strings.
The second major change is that the glib.variant.VariantG type system supports the concept of ‘indefinite types’ — types that are less specific than the normal types found in D-Bus. For example, it is possible to speak of ‘an array of any type’ in glib.variant.VariantG, where the D-Bus type system would require you to speak of ‘an array of integers’ or ‘an array of strings’. Indefinite types have been added by introducing the characters *, ? and r to type strings.
Finally, all arbitrary restrictions relating to the complexity of types are lifted along with the restriction that dictionary entries may only appear nested inside of arrays.
Just as in D-Bus, glib.variant.VariantG types are described with strings (‘type strings’). Subject to the differences mentioned above, these strings are of the same form as those found in D-Bus. Note, however: D-Bus always works in terms of messages and therefore individual type strings appear nowhere in its interface. Instead, ‘signatures’ are a concatenation of the strings of the type of each argument in a message. glib.variant.VariantG deals with single values directly so glib.variant.VariantG type strings always describe the type of exactly one value. This means that a D-Bus signature string is generally not a valid glib.variant.VariantG type string — except in the case that it is the signature of a message containing exactly one argument.
An indefinite type is similar in spirit to what may be called an abstract type in other type systems. No value can exist that has an indefinite type as its type, but values can exist that have types that are subtypes of indefinite types. That is to say, glib.variant.VariantG.getType will never return an indefinite type, but calling glib.variant.VariantG.isOfType with an indefinite type may return true. For example, you cannot have a value that represents ‘an array of no particular type’, but you can have an ‘array of integers’ which certainly matches the type of ‘an array of no particular type’, since ‘array of integers’ is a subtype of ‘array of no particular type’.
This is similar to how instances of abstract classes may not directly exist in other type systems, but instances of their non-abstract subtypes may. For example, in GTK, no object that has the type of [gtk.widget.Widget] can exist (since gtk.widget.Widget is an abstract class), but a [gtk.window.Window] can certainly be instantiated, and you would say that a gtk.window.Window is a gtk.widget.Widget (since gtk.window.Window is a subclass of gtk.widget.Widget).
Two types may not be compared by value; use glib.variant_type.VariantType.equal or glib.variant_type.VariantType.isSubtypeOf May be copied using glib.variant_type.VariantType.copy and freed using glib.variant_type.VariantType.free.
GVariant Type Strings
A glib.variant.VariantG type string can be any of the following:
A basic type string describes a basic type (as per glib.variant_type.VariantType.isBasic) and is always a single character in length. The valid basic type strings are b, y, n, q, i, u, x, t, h, d, s, o, g and ?.
The above definition is recursive to arbitrary depth. aaaaai and (ui(nq((y)))s) are both valid type strings, as is a(aa(ui)(qna{ya(yd)})). In order to not hit memory limits, glib.variant.VariantG imposes a limit on recursion depth of 65 nested containers. This is the limit in the D-Bus specification (64) plus one to allow a [gio.dbus_message.DBusMessage] to be nested in a top-level tuple.
The meaning of each of the characters is as follows:
The first type (the basic type) is the key type and the second type is the value type. The reason that the first type is restricted to being a basic type is so that it can easily be hashed.
Any type string of a container that contains an indefinite type is, itself, an indefinite type. For example, the type string a* (corresponding to G_VARIANT_TYPE_ARRAY) is an indefinite type that is a supertype of every array type. (*s) is a supertype of all tuples that contain exactly two items where the second item is a string.
a{?*} is an indefinite type that is a supertype of all arrays containing dictionary entries where the key is any basic type and the value is any type at all. This is, by definition, a dictionary, so this type string corresponds to G_VARIANT_TYPE_DICTIONARY. Note that, due to the restriction that the key of a dictionary entry must be a basic type, {**} is not a valid type string.