Examples

This directory contains a collection of examples. This isn't an exhaustive collection though, if one is missing, please ask, or contribute. PRs are welcome

The examples are written in a difficulty/discovery order. Concepts that are explained in an example is not necessarily re-explained in a next example.

Basics

1. Instantiating a module, explains the basics of using Wasmer and how to create an instance out of a WebAssembly module.

   Keywords: instance, module.

   Execute the example

   $ crystal examples/instance.cr

Engines

2. JIT engine, explains what an engine is, what the JIT engine is, and how to set it up. The example completes itself with the compilation of the Wasm module, its instantiation, and finally, by calling an exported function.

   Keywords: JIT, engine, in-memory, executable code.

   Execute the example

   $ crystal examples/engine_jit.cr

Compilers

3. Cranelift compiler, explains how to use the wasmer-compiler-cranelift compiler.

   Keywords: compiler, cranelift.

   Execute the example

   $ crystal examples/compiler_cranelift.cr

Exports

4. Exported function, explains how to get and how to call an exported function.

   Keywords: export, function.

   Execute the example

   $ crystal examples/exports_function.cr

5. Exported memory, explains how to read from and write into an exported memory.

   Keywords: export, function.

   Execute the example

   $ crystal examples/exports_memory.cr

6. Exported global, explains how to work with exported globals: get/set their value, have information about their type.

   Keywords: export, global.

   Execute the example

   $ crystal examples/exports_global.cr

Imports

7. Imported function, aka host function, explains how to use a Crystal function inside a WebAssembly module.

   Keywords: import, function.

   Execute the example

   $ crystal examples/imports_function.cr

8. Early exit, explains how to early exit from a host function, and how to catch the error later.

   Keywords: import, function, error.

   Execute the example

   $ crystal examples/imports_function_early_exit.cr

Integrations

9. WASI, explains how to use the WebAssembly System Interface (WASI).

   Keywords: wasi, system, interface

   Execute the example

   $ crystal examples/wasi.cr