Type reference

The type table, both directions. Anything not listed is a compile-time diagnostic naming the file, line and column.

V type	Python type	Direction and notes
bool	bool	Any object in (truth test); True/False out
i8, i16, i32, int, i64, isize	int	Range-checked in; overflow raises OverflowError
u8, u16, u32, u64, usize	int	Negative or overflow raises OverflowError
f32, f64	float	An int is accepted
rune	int	The code point
string	str	UTF-8
[]u8	bytes	Bytes-like in without copying; a new bytes out
[]T	list	Any sequence in; a list out
[N]T	list	Exactly N items in; a list out
?T	T or None	none ↔ None
map[K]T (K scalar or str)	dict	Scalar/str keys; a new dict out
(A, B, …) (result)	tuple	Multi-value return only
math.complex.Complex	complex
voidptr	any	Borrowed; the reference is yours
vcraft.PyObj (result)	any	Owned; the reference goes to the caller
&T (T a @[vc_class])	T	Instance reference; accepts a subclass
an enum	that enum.IntEnum	Member in/out; a non-member raises ValueError
a plain struct	dict	Field names as keys
void, !void	None
!T	T or raises	See Errors and panics

Composite elements

A container element may itself be a container, an enum or a plain struct: ?[]int, [][]int, map[string][]int, []Color, []Point all cross. The element of []u8 is special-cased to bytes; a u8 element elsewhere has no reader.

Fields

A @[vc_class] field follows the table but is limited to scalars and @[vc_ref] references: a string or []T in CPython-owned memory would be a pointer V's collector cannot see. A plain struct field may be any type with a rule, checked recursively.