Struct Caller

pub struct Caller<'a> { /* private fields */ }

A structure representing the caller’s context when creating a function via Func::wrap.

This structure can be taken as the first parameter of a closure passed to Func::wrap, and it can be used to learn information about the caller of the function, such as the calling module’s memory, exports, etc.

The primary purpose of this structure is to provide access to the caller’s information, such as it’s exported memory. This allows functions which take pointers as arguments to easily read the memory the pointers point into.

Note that this is intended to be a pretty temporary mechanism for accessing the caller’s memory until interface types has been fully standardized and implemented.

Implementations

impl Caller<'_>

pub fn get_export(&self, name: &str) -> Option<Extern>

Looks up an export from the caller’s module by the name given.

Note that this function is only implemented for the Extern::Memory type currently. No other exported structure can be acquired through this just yet, but this may be implemented in the future!

Return

If a memory export with the name provided was found, then it is returned as a Memory. There are a number of situations, however, where the memory may not be available:

• The caller instance may not have an export named name
• The export named name may not be an exported memory
• There may not be a caller available, for example if Func was called directly from host code.

It’s recommended to take care when calling this API and gracefully handling a None return value.

pub fn store(&self) -> Store

Get a handle to this caller’s store.