feat: add more examples, work on new public api

Signed-off-by: Henry Gressmann <mail@henrygressmann.de>

8 files changed, 62 insertions, 9 deletions

diff --git a/examples/README.md b/examples/README.md
index ce47073..94f974b 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -1,10 +1,10 @@
 # Examples
 
-## WasmRust
+## Wasm-Rust
 
 These are examples using WebAssembly generated from Rust code.
-To run these, you first need to build the Rust code into WebAssembly, since the wasm files are not included in the repository to keep it small.
-This requires the `wasm32-unknown-unknown` target and `wasm-opt` to be installed (available via Binaryen).
+To run these, you first need to build the Rust code, since the resulting wasm files are not included in the repository to keep it small.
+This requires the `wasm32-unknown-unknown` target and `wasm-opt` to be installed (available via [Binaryen](https://github.com/WebAssembly/binaryen)).
 
 ```bash
 $ ./examples/rust/build.sh
@@ -20,3 +20,4 @@ Where `<example>` is one of the following:
 
 - `hello`: A simple example that prints a number to the console.
 - `tinywasm`: Runs `hello` using TinyWasm - inside of TinyWasm itself!
+- `fibonacci`: Calculates the x-th Fibonacci number.
diff --git a/examples/rust/Cargo.toml b/examples/rust/Cargo.toml
index 9ff80dc..d557392 100644
--- a/examples/rust/Cargo.toml
+++ b/examples/rust/Cargo.toml
@@ -1,5 +1,8 @@
 cargo-features=["per-package-target"]
 
+# treat this as an independent package
+[workspace]
+
 [package]
 publish=false
 name="rust-wasm-examples"
@@ -16,3 +19,14 @@ path="src/hello.rs"
 [[bin]]
 name="tinywasm"
 path="src/tinywasm.rs"
+
+[[bin]]
+name="fibonacci"
+path="src/fibonacci.rs"
+
+[profile.wasm]
+opt-level="s"
+lto="thin"
+codegen-units=1
+panic="abort"
+inherits="release"
diff --git a/examples/rust/README.md b/examples/rust/README.md
index 8ecac52..1b6be2f 100644
--- a/examples/rust/README.md
+++ b/examples/rust/README.md
@@ -1 +1,4 @@
-# Examples using Rust compiled to WebAssembly
+# WebAssembly Rust Examples
+
+This is a seperate crate that generates WebAssembly from Rust code.
+It is used by the `wasm-rust` example.
diff --git a/examples/rust/build.sh b/examples/rust/build.sh
index 2c8069a..a8c587a 100755
--- a/examples/rust/build.sh
+++ b/examples/rust/build.sh
@@ -1,11 +1,14 @@
 #!/usr/bin/env bash
 cd "$(dirname "$0")"
 
-bins=("hello" "tinywasm")
+bins=("hello" "tinywasm" "fibonacci")
 exclude_wat=("tinywasm")
-out_dir="../../target/wasm32-unknown-unknown/wasm"
+out_dir="./target/wasm32-unknown-unknown/wasm"
 dest_dir="out"
 
+# ensure out dir exists
+mkdir -p "$dest_dir"
+
 for bin in "${bins[@]}"; do
     cargo build --target wasm32-unknown-unknown --package rust-wasm-examples --profile=wasm --bin "$bin"
 
diff --git a/examples/rust/src/fibonacci.rs b/examples/rust/src/fibonacci.rs
new file mode 100644
index 0000000..7493132
--- /dev/null
+++ b/examples/rust/src/fibonacci.rs
@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+#[cfg(not(test))]
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    core::arch::wasm32::unreachable()
+}
+
+#[no_mangle]
+// The rust compiler will convert this to an iterative algorithm.
+pub extern "C" fn fibonacci(n: i32) -> i32 {
+    if n <= 1 {
+        return n;
+    }
+    fibonacci(n - 1) + fibonacci(n - 2)
+}
diff --git a/examples/rust/src/tinywasm.rs b/examples/rust/src/tinywasm.rs
index 0f18ab9..0fb9261 100644
--- a/examples/rust/src/tinywasm.rs
+++ b/examples/rust/src/tinywasm.rs
@@ -26,7 +26,7 @@ fn run() -> tinywasm::Result<()> {
     )?;
     let instance = module.instantiate(&mut store, Some(imports))?;
 
-    let add_and_print = instance.typed_func::<(i32, i32), ()>(&mut store, "add_and_print")?;
+    let add_and_print = instance.exported_func::<(i32, i32), ()>(&mut store, "add_and_print")?;
     add_and_print.call(&mut store, (1, 2))?;
     Ok(())
 }
diff --git a/examples/wasm-rust.rs b/examples/wasm-rust.rs
index 3b8877e..3b26863 100644
--- a/examples/wasm-rust.rs
+++ b/examples/wasm-rust.rs
@@ -13,6 +13,7 @@ fn main() -> Result<()> {
 
     match args[1].as_str() {
         "hello" => hello()?,
+        "fibonacci" => fibonacci()?,
         "tinywasm" => tinywasm()?,
         _ => {}
     }
@@ -36,7 +37,7 @@ fn tinywasm() -> Result<()> {
     )?;
     let instance = module.instantiate(&mut store, Some(imports))?;
 
-    let hello = instance.typed_func::<(), ()>(&mut store, "hello")?;
+    let hello = instance.exported_func::<(), ()>(&mut store, "hello")?;
     hello.call(&mut store, ())?;
 
     Ok(())
@@ -58,8 +59,22 @@ fn hello() -> Result<()> {
     )?;
 
     let instance = module.instantiate(&mut store, Some(imports))?;
-    let add_and_print = instance.typed_func::<(i32, i32), ()>(&mut store, "add_and_print")?;
+    let add_and_print = instance.exported_func::<(i32, i32), ()>(&mut store, "add_and_print")?;
     add_and_print.call(&mut store, (1, 2))?;
 
     Ok(())
 }
+
+fn fibonacci() -> Result<()> {
+    const FIBONACCI_WASM: &[u8] = include_bytes!("./rust/out/fibonacci.wasm");
+    let module = Module::parse_bytes(&FIBONACCI_WASM)?;
+    let mut store = Store::default();
+
+    let instance = module.instantiate(&mut store, None)?;
+    let fibonacci = instance.exported_func::<i32, i32>(&mut store, "fibonacci")?;
+    let n = 30;
+    let result = fibonacci.call(&mut store, n)?;
+    println!("fibonacci({}) = {}", n, result);
+
+    Ok(())
+}
diff --git a/examples/wasm/add.wasm b/examples/wasm/add.wasm
new file mode 100644
index 0000000..92e3432
--- /dev/null
+++ b/examples/wasm/add.wasm