Overview

The wasmedge-sys crate defines a group of low-level Rust APIs for WasmEdge, a light-weight, high-performance, and extensible WebAssembly runtime for cloud-native, edge, and decentralized applications.

For developers, it is recommended that the APIs in wasmedge-sys are used to construct high-level libraries, while wasmedge-sdk (coming soon) is for building up business applications.

Usage

To use or build the wasmedge-sys crate, the wasmedge-core is required. The Build wasmedge-sys crate section of WasmEdge Docs gives the tips.

Example

A quick-start example below is using wasmedge-sys to run a WebAssembly module written with its WAT format (textual format):

```rust use wasmedgesys::{Vm, WasmValue}; use wasmedgetypes::wat2wasm;

[cfg_attr(test, test)]

fn main() -> Result<(), Box> { // read the wasm bytes let wasmbytes = wat2wasm( br#" (module (export "fib" (func $fib)) (func $fib (param $n i32) (result i32) (if (i32.lts (getlocal $n) (i32.const 2) ) (return (i32.const 1) ) ) (return (i32.add (call $fib (i32.sub (getlocal $n) (i32.const 2) ) ) (call $fib (i32.sub (get_local $n) (i32.const 1) ) ) ) ) ) ) "#, )?;

// create a Vm instance
let mut vm = Vm::create(None, None)?;

// register the wasm bytes
let module_name = "extern-module";
vm.register_wasm_from_buffer(module_name, &wasm_bytes)?;

// run the exported function named "fib"
let func_name = "fib";
let result = vm.run_registered_function(module_name, func_name, [WasmValue::from_i32(5)])?;

assert_eq!(result.len(), 1);
assert_eq!(result[0].to_i32(), 8);

Ok(())

} ```

See also