feat: implement pattern matching through is/match expressions and destructuring

.github/workflows/rust.yml

@@ -0,0 +1,26 @@
+name: Rust
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
+env:
+  CARGO_TERM_COLOR: always
+  RUSTFLAGS: -Dwarnings
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build
+        run: cargo build --verbose
+      - name: Run tests
+        run: cargo test --verbose --workspace

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "compose-utils",
     "compose",
     "compose-error-codes",
+    "compose-error-codes-doc-tests",
     "compose-doc-macros",
     "compose-doc",
     "compose-codespan-reporting"
@@ -36,10 +37,12 @@ compose-macros = { path = "compose-macros" }
 compose-syntax = { path = "compose-syntax" }
 compose-utils = { path = "compose-utils" }
 compose-error-codes = { path = "compose-error-codes" }
+compose-error-codes-doc-tests = { path = "compose-error-codes-doc-tests" }
 compose-editor = { path = "compose-editor" }
 compose-doc-macros = { path = "compose-doc-macros" }
 compose-doc = { path = "compose-doc" }
 compose-codespan-reporting = { path = "compose-codespan-reporting" }
+itertools = "0.14.0"
 
 [workspace.lints.rust]
 unsafe_code = "deny"

compose-cli/src/explain.rs

@@ -15,7 +15,14 @@ pub(crate) fn explain(code: &str) -> Result<(), CliError> {
         Some(code) => {
             let md_text = code.description;
 
-            let explained = match compose_doc::transform_markdown(md_text, &Config::ansi()) {
+            let explained = match compose_doc::transform_markdown(
+                md_text,
+                &Config::new()
+                    .with_ansi()
+                    // make sure that the explain command works even if the explanation is technically not fully accurate
+                    .with_output_block_error_mode(compose_doc::ErrorHandlingMode::Ignore)
+                    .with_code_block_error_mode(compose_doc::ErrorHandlingMode::Ignore),
+            ) {
                 Ok(v) => v,
                 Err(e) => {
                     eprintln!(

compose-cli/src/world.rs

@@ -110,11 +110,11 @@ impl World for SystemWorld {
         &self.library
     }
 
-    fn write(&self, f: &dyn Fn(&mut dyn Write) -> std::io::Result<()>) -> std::io::Result<()> {
+    fn write(&self, f: &mut dyn FnMut(&mut dyn Write) -> std::io::Result<()>) -> std::io::Result<()> {
         f(&mut std::io::stdout())
     }
 
-    fn read(&self, f: &dyn Fn(&mut dyn Read) -> std::io::Result<()>) -> std::io::Result<()> {
+    fn read(&self, f: &mut dyn FnMut(&mut dyn Read) -> std::io::Result<()>) -> std::io::Result<()> {
         f(&mut std::io::stdin())
     }
 

compose-doc-macros/src/lib.rs

@@ -1,29 +1,34 @@
+use compose_doc::ErrorHandlingMode;
 use proc_macro::TokenStream as BoundaryStream;
 use quote::quote;
 use syn::spanned::Spanned;
-use syn::{parse_macro_input, Attribute, Item};
+use syn::{Attribute, Item, parse_macro_input};
 use unindent::unindent;
 
 #[proc_macro]
 pub fn compose_doc(input: BoundaryStream) -> BoundaryStream {
     let ComposeDocInput { attrs, item } = parse_macro_input!(input as ComposeDocInput);
 
-    let lines: Vec<_> = attrs.iter()
-        .filter_map(extract_doc_line)
-        .collect();
+    let lines: Vec<_> = attrs.iter().filter_map(extract_doc_line).collect();
 
     let markdown = unindent(&lines.join("\n"));
 
     // Transform markdown
-    let transformed =
-        match compose_doc::transform_markdown(&markdown, &compose_doc::Config::no_color()) {
-            Ok(t) => t,
-            Err(e) => {
-                return syn::Error::new_spanned(&item, format!("{}: {}", e.line, e.message))
-                    .to_compile_error()
-                    .into();
-            }
-        };
+    let transformed = match compose_doc::transform_markdown(
+        &markdown,
+        &compose_doc::Config::new()
+            .with_no_color()
+            .with_code_block_error_mode(ErrorHandlingMode::EmitAsTests)
+            .with_output_block_error_mode(ErrorHandlingMode::EmitAsTests),
+
+    ) {
+        Ok(t) => t,
+        Err(e) => {
+            return syn::Error::new_spanned(&item, format!("{}: {}", e.line, e.message))
+                .to_compile_error()
+                .into();
+        }
+    };
 
     let doc_lines = transformed.lines().map(|line| quote! { #[doc = #line] });
 
@@ -38,7 +43,6 @@ pub fn compose_doc(input: BoundaryStream) -> BoundaryStream {
     output.into()
 }
 
-
 struct ComposeDocInput {
     attrs: Vec<Attribute>,
     item: Item,

compose-doc/src/lib.rs

@@ -135,16 +135,17 @@ If a block:
 - emits diagnostics not marked with `error(...)` or `warn(...)`, or
 - claims to emit diagnostics that aren’t produced by the code,
 
-then `transform_markdown` will fail with a line-referenced error.
+then [`transform_markdown`] will fail with a line-referenced error.
 
 ---
 
 ## 🛠️ Configuration
 
 ```rust
 use compose_doc::Config;
-let config = Config::ansi();      // diagnostics with colour
-let config = Config::no_color();  // plain-text diagnostics
+
+let config = Config::new().with_ansi();      // diagnostics with colour
+let config = Config::new().with_no_color();  // plain-text diagnostics
 ```
 */
 mod block;
@@ -285,7 +286,7 @@ mod tests {
         "#};
 
         let output =
-            transform_markdown(input, &Config::no_color()).expect("failed to transform markdown");
+            transform_markdown(input, &Config::new().with_no_color()).expect("failed to transform markdown");
 
         assert_eq!(
             output.trim(),
@@ -332,7 +333,7 @@ mod tests {
         "#};
 
         let output =
-            transform_markdown(input, &Config::no_color()).expect("failed to transform markdown");
+            transform_markdown(input, &Config::new().with_no_color()).expect("failed to transform markdown");
 
         assert_eq!(
             output.trim(),