Types and Literals

Built-in Types

Here are the built-in types that Fluxx supports:

Type	Example literal(s)	Range/notes
bool	true, false
byte	42	0 to 255 (unsigned 8-bit integer)
sbyte	-42	-128 to 127 (signed 8-bit integer)
char	'a' '$' '\u006A'	U+0000 to U+FFFF (16-bit character)
int	42	-2,147,483,648 to 2,147,483,647 (signed 32-bit integer)
uint	42	0 to 4,294,967,295 (unsigned 32-bit integer)
long	42	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 (signed 64-bit integer)
ulong	42	0 to 18,446,744,073,709,551,615 (unsigned 64-bit integer)
double	1.42	64-bit floating point
float	1.42	32-bit floating point
string	"foo"	Unicode string
uitext	<uitext id=BackLabel; Go back/>	Localizable text (see below)

Most of these data types should be familiar, especially to C# developers.

Localizable text

Fluxx is unique in that it has a special data type, uitext, for localizable text. It allows for localizable UI with the UI text (optionally) embedded directly in the UI markup.

uitext has an optional id property for a resource string ID and description property for a comment:

<input type=button
    value=<uitext Go back />
/input>

<input type=button
    value=<uitext id=BackLabel; description=Label for nav bar back button; Go back />
/input>

Fluxx build tooling can automatically generate localizable resource files from the uitext literals. Alternatively, just specififying the id property allows loading a UI string defined elsewhere:

<input type=button
    value=<uitext id=BackLabel />
/input>

Treating localizable text as a separate data type from string means the tooling knows what’s localizable and what isn’t and the type checker can help ensure that the developer doesn’t make mistakes, failing to localize something that should be translated. It also allows the editor to show UI text in a different visual style.