Update rust guide and tutorial examples to use registries for WITs

Signed-off-by: Kate Goldenring <[email protected]>

Author: kate-goldenring

component-model/examples/tutorial/adder/Cargo-component.lock

@@ -0,0 +1,12 @@
+# This file is automatically generated by cargo-component.
+# It is not intended for manual editing.
+version = 1
+
+[[package]]
+name = "docs:adder"
+registry = "ghcr.io/bytecodealliance"
+
+[[package.version]]
+requirement = "^0.1.0"
+version = "0.1.0"
+digest = "sha256:d4cb950366f8756821c401ec496ad43b35ffb0df3b2e757eb6aa3c1fa30d38c2"

component-model/examples/tutorial/adder/Cargo.toml

@@ -9,11 +9,7 @@ wit-bindgen-rt = { version = "0.37.0", features = ["bitflags"] }
 [lib]
 crate-type = ["cdylib"]
 
-[package.metadata.component]
-package = "docs:adder"
-
-[package.metadata.component.dependencies]
-
 [package.metadata.component.target]
-path = "../wit/adder"
-world = "adder"
+package = "docs:adder"
+version = "0.1.0"
+registry = "ghcr.io/bytecodealliance"

component-model/examples/tutorial/calculator/Cargo-component.lock

@@ -0,0 +1,12 @@
+# This file is automatically generated by cargo-component.
+# It is not intended for manual editing.
+version = 1
+
+[[package]]
+name = "docs:calculator"
+registry = "ghcr.io/bytecodealliance"
+
+[[package.version]]
+requirement = "^0.1.0"
+version = "0.1.0"
+digest = "sha256:c76216435b03e235615b16c17e80fdef5ffa90f5fea4a1138cfaaa978a0fb347"

component-model/examples/tutorial/calculator/Cargo.toml

@@ -9,14 +9,7 @@ wit-bindgen-rt = { version = "0.24.0", features = ["bitflags"] }
 [lib]
 crate-type = ["cdylib"]
 
-[package.metadata.component]
-package = "docs:calculator"
-
-[package.metadata.component.target.dependencies]
-"docs:adder" = { path = "../wit/adder" }  # directory containing the WIT package
-
 [package.metadata.component.target]
-path = "../wit/calculator"
-world = "calculator"
-
-[package.metadata.component.dependencies]
+package = "docs:calculator"
+version = "0.1.0"
+registry = "ghcr.io/bytecodealliance"

component-model/src/language-support/rust.md

@@ -35,19 +35,17 @@ cargo component new add --lib && cd add
 
 ## 3. Adding the WIT world
 
-We now need to change our generated `wit/world.wit` to match `docs:adder`:
-```wit
-{{#include ../../examples/tutorial/wit/adder/world.wit}}
-```
-
-The `package.metadata.component` section of our `Cargo.toml` should be changed
-to the following:
+Now, that we have a template generated for our app, we can use [`cargo-component`'s registries support](https://github.com/bytecodealliance/cargo-component/blob/main/docs/design/registries.md#component-registries) to fetch the `docs:adder` package and generate bindings for our component. Modify the `package` section of our `Cargo.toml` to only contain the following target definition:
 
 ```toml
-[package.metadata.component]
+[package.metadata.component.target]
 package = "docs:adder"
+version = "0.1.0"
+registry = "ghcr.io/bytecodealliance"
 ```
 
+This tells `cargo-component` to fetch the world from `ghcr.io/bytecodealliance/docs/adder:0.1.0`.
+
 ## 4. Generating bindings
 
 Now that we've updated our `world.wit` and `Cargo.toml`, we can re-generate
@@ -110,7 +108,7 @@ package docs:[email protected] {
 ### Running a Component
 
 To verify that our component works, lets run it from a Rust application that knows how to run a
-component targeting the [`adder` world](#adding-the-wit-world).
+component targeting the [`adder` world](#3-adding-the-wit-world).
 
 The application uses [`wasmtime`](https://github.com/bytecodealliance/wasmtime) crates to generate
 Rust bindings, bring in WASI worlds, and execute the component.