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WebAssembly with Grain

  1. Setting up the environment

    To install Grain on your local system, follow the instructions given here, and to install Wasmtime to run our .wasm file, you can take a look at their website.

  2. Code

    Open your preferred text editor and make a file with .gr extension. Grain recommends VS Code to work with .gr files. Installation of grain extension for VS code is highly recommended.

    The Fibonacci code in Grain is as follows :

    let rec fibonacci = (n) => {
    if (n == 0 || n == 1) {
    } else {
    fibonacci(n - 1) + fibonacci(n - 2)


    We need to mention that a function is recursive with the keyword recin Grain.

  3. Compiling the code

    To compile your Grain code, simply run :


    This would print 13 on your terminal and generate a file.

  1. Running .wasm file in Wasmtime

    To run our .wasm file in wasmtime, run the following command