Overview

The wasmedge-sdk crate defines a group of high-level Rust APIs, which are used to build up business applications.

• Notice that wasmedge-sdk requires Rust v1.66 or above in the stable channel.

Build

To use or build the wasmedge-sdk crate, the WasmEdge library is required. Please refer to WasmEdge Installation and Uninstallation to install the WasmEdge library.

• The following table provides the versioning information about each crate of WasmEdge Rust bindings.

  | wasmedge-sdk | WasmEdge lib | wasmedge-sys | wasmedge-types| wasmedge-macro| | :-----------: | :-----------: | :-----------: | :-----------: | :-----------: | | 0.8.0 | 0.12.0 | 0.13.0 | 0.4.1 | 0.3.0 | | 0.7.1 | 0.11.2 | 0.12.2 | 0.3.1 | 0.3.0 | | 0.7.0 | 0.11.2 | 0.12 | 0.3.1 | 0.3.0 | | 0.6.0 | 0.11.2 | 0.11 | 0.3.0 | 0.2.0 | | 0.5.0 | 0.11.1 | 0.10 | 0.3.0 | 0.1.0 | | 0.4.0 | 0.11.0 | 0.9 | 0.2.1 | - | | 0.3.0 | 0.10.1 | 0.8 | 0.2 | - | | 0.1.0 | 0.10.0 | 0.7 | 0.1 | - |

Example

The example below is using wasmedge-sdk to run a WebAssembly module written with its WAT format (textual format). If you would like more examples, please refer to Examples of WasmEdge RustSDK.

```rust use wasmedgesdk::{ error::HostFuncError, hostfunction, params, wat2wasm, Caller, ImportObjectBuilder, Module, VmBuilder, WasmValue, };

// We define a function to act as our "env" "say_hello" function imported in the // Wasm program above.

[host_function]

pub fn sayhello(caller: Caller, _args: Vec) -> Result, HostFuncError> { println!("Hello, world!");

Ok(vec![])

}

[cfg_attr(test, test)]

fn main() -> anyhow::Result<()> { // create an import module let import = ImportObjectBuilder::new() .withfunc::<(), ()>("sayhello", say_hello)? .build("env")?;

let wasm_bytes = wat2wasm(
    br#"
(module
  ;; First we define a type with no parameters and no results.
  (type $no_args_no_rets_t (func (param) (result)))

  ;; Then we declare that we want to import a function named "env" "say_hello" with
  ;; that type signature.
  (import "env" "say_hello" (func $say_hello (type $no_args_no_rets_t)))

  ;; Finally we create an entrypoint that calls our imported function.
  (func $run (type $no_args_no_rets_t)
    (call $say_hello))
  ;; And mark it as an exported function named "run".
  (export "run" (func $run)))
"#,
)?;

// loads a wasm module from the given in-memory bytes
let module = Module::from_bytes(None, wasm_bytes)?;

// create an executor
VmBuilder::new()
    .build()?
    .register_import_module(import)?
    .register_module(Some("extern"), module)?
    .run_func(Some("extern"), "run", params!())?;

Ok(())

}

```