Attributes

Attributes are special directives that can add extra configuration individual variables and types.

struct RGBA8 {
  u8 red   [[color("FF0000")]];
  u8 green [[color("00FF00")]];
  u8 blue  [[color("0000FF")]];
} [[static]];

Note

Attributes can either have no arguments: [[attribute_name]]
Or a single string argument: [[attribute_name("attribute_value")]]

It’s also possible to apply multiple attributes to the same variable or type: [[attribute1, attribute2]]

Variable Attributes

Note

1.16.0 Variable attributes may also be applied to types directly to cause all patterns created from them to have those attributes applied.

[[color("RRGGBB")]]

Changes the color the variable is being highlighted in the hex editor.

[[name("new_name")]]

Changes the display name of the variable in the pattern data view without affecting the rest of the program.

[[comment("text")]]

Adds a comment to the current variable that is displayed when hovering over it in the pattern data view.

[[format("formatter_function_name")]]

Overrides the default display value formatter with a custom function. The function requires a single argument representing the value to be formatted (e.g u32 if this attribute was applied to a variable of type u32) and return a string which will be displayed in place of the default value.

It’s also possible to return a pattern or value from this function which will then be default formatted using the default pattern language rules. v1.22.0

[[format_entries("formatter_function_name")]] 1.15.0

Can be applied to arrays and works the same as the [[format]] attribute but overrides the default dispay value formatter of all array entries instead of just the array pattern itself.

[[hidden]]

Prevents a variable from being shown in the pattern data view but still be usable from the rest of the program.

[[inline]] 1.10.1

Can only be applied to Arrays and Struct-like types. Visually inlines all members of this variable into the parent scope. Useful to flatten the displayed tree structure and avoid unnecessary indentation while keeping the pattern structured.

[[transform("transformer_function_name")]] 1.10.1

Specifies a function that will be executed to preprocess the value read from that variable before it’s being accessed through the dot syntax (some_struct.some_value). The function requires a single argument representing the original value that was read (e.g u32 if this attribute was applied to a variable of type u32) and return a value that will be returned instead.

[[pointer_base("pointer_base_function_name")]] 1.10.1

Specifies a function that will be executed to preprocess the address of the pointer this attribute was applied to points to. The function requires a single argument representing the original pointer address that was read (e.g u32 if this attribute was applied to a pointer with size type u32) and return the offset the pointer should point to instead.

There’s a number of predefined pointer helper functions available in the standard library to rebase pointers off of different places.

[[no_unique_address]] 1.14.0

A variable marked by this attribute will be placed in memory but not increment the current cursor position.

[[single_color]] 1.16.0

Forces all members of the struct, union or array to be highlighted using the same color instead of individual ones

Type Attributes

[[static]]

The Pattern Language by default optimizes arrays of built-in types so they don’t use up as much memory and are evaluated quicker.
This same optimization can be applied to custom data types when they are marked with this attribute to tell the runtime the size and layout of this type will always be the same.
However if the layout of the type this is applied to is not static, highlighing and decoding of the data will be wrong and only use the layout of the first array entry.

[[left_to_right]] / [[right_to_left]] 1.15.0

These attributes can be applied to bitfields to set if bits should be indexed from left to right or from right to left

[[sealed]] 1.20.0

These attributes can be applied to structs, unions and bitfields. It causes tools that display Patterns in some way to not display the implementation details (such as children of this type) anymore but instead treat like a built-in type. This is mainly useful for making custom types that should decode and display the bytes in a custom format using the [[format]] attribute.