chore: Edition 2024 (#2195)

Migrates the package to rust's `edition 2024`. Closes #2144 
This PR's changes come almost completely from automated tools.

It may be easier to look at them commit by commit. In order,
1. run `cargo fix edition` and remove some backwards-compatibility
changes (e.g. matching on `expr_2021` instead of `expr` in macro_rules).
2. run `cargo fmt`
3. fix new lints coming in `rust 1.87`.

The last commit is the noisiest one, and totally optional:
4. `clippy --fix`es some additional non-default lints,
  - Ensuring code links in the rustdocs are formated using backticks.
  - Adding some `must_use`s
  - Replacing matches on `bool` with if/else
  - Removing unnecessary `into_iter` calls
  - etc.
  
I'll make sure to `.git-ignore-revs` this change to avoid polluting the
git history.

Author: aborgna-q

Cargo.toml

@@ -16,7 +16,7 @@ default-members = ["hugr", "hugr-core", "hugr-passes", "hugr-cli", "hugr-model"]
 
 [workspace.package]
 rust-version = "1.85"
-edition = "2021"
+edition = "2024"
 homepage = "https://github.com/CQCL/hugr"
 repository = "https://github.com/CQCL/hugr"
 license = "Apache-2.0"
@@ -31,11 +31,16 @@ unexpected_cfgs = { level = "warn", check-cfg = [
 ] }
 
 missing_docs = "warn"
+
 [workspace.lints.clippy]
 # Unstable check, may cause false positives.
 # https://github.com/rust-lang/rust-clippy/issues/5112
 debug_assert_with_mut_call = "warn"
 
+# TODO: Reduce the size of error types.
+result_large_err = "allow"
+large_enum_variant = "allow"
+
 [workspace.dependencies]
 insta = { version = "1.42.2" }
 bitvec = "1.0.1"

hugr-cli/src/extensions.rs

@@ -28,7 +28,7 @@ impl ExtArgs {
     pub fn run_dump(&self, registry: &ExtensionRegistry) {
         let base_dir = &self.outdir;
 
-        for ext in registry.iter() {
+        for ext in registry {
             let mut path = base_dir.clone();
             for part in ext.name().split('.') {
                 path.push(part);

hugr-cli/src/hugr_io.rs

@@ -1,7 +1,7 @@
 //! Input/output arguments for the HUGR CLI.
 
 use clio::Input;
-use hugr::envelope::{read_envelope, EnvelopeError};
+use hugr::envelope::{EnvelopeError, read_envelope};
 use hugr::extension::ExtensionRegistry;
 use hugr::package::Package;
 use hugr::{Extension, Hugr};
@@ -43,7 +43,7 @@ impl HugrInputArgs {
     /// Read a hugr envelope from the input and return the package encoded
     /// within.
     ///
-    /// If [HugrInputArgs::hugr_json] is `true`, [HugrInputArgs::get_hugr] should be called instead as
+    /// If [`HugrInputArgs::hugr_json`] is `true`, [`HugrInputArgs::get_hugr`] should be called instead as
     /// reading the input as a package will fail.
     pub fn get_package(&mut self) -> Result<Package, CliError> {
         let extensions = self.load_extensions()?;
@@ -58,9 +58,9 @@ impl HugrInputArgs {
     /// Read a hugr JSON file from the input.
     ///
     /// This is a legacy option for reading old HUGR JSON files when the
-    /// [HugrInputArgs::hugr_json] flag is used.
+    /// [`HugrInputArgs::hugr_json`] flag is used.
     ///
-    /// For most cases, [HugrInputArgs::get_package] should be called instead.
+    /// For most cases, [`HugrInputArgs::get_package`] should be called instead.
     pub fn get_hugr(&mut self) -> Result<Hugr, CliError> {
         let extensions = self.load_extensions()?;
         let mut buffer = BufReader::new(&mut self.input);
@@ -79,8 +79,8 @@ impl HugrInputArgs {
 
     /// Return a register with the selected extensions.
     ///
-    /// This includes the standard extensions if [HugrInputArgs::no_std] is `false`,
-    /// and the extensions loaded from the paths in [HugrInputArgs::extensions].
+    /// This includes the standard extensions if [`HugrInputArgs::no_std`] is `false`,
+    /// and the extensions loaded from the paths in [`HugrInputArgs::extensions`].
     pub fn load_extensions(&self) -> Result<ExtensionRegistry, CliError> {
         let mut reg = if self.no_std {
             hugr::extension::PRELUDE_REGISTRY.to_owned()

hugr-cli/src/lib.rs

@@ -56,7 +56,7 @@
 //!   [INPUT]                    Input file. Defaults to `-` for stdin.
 //! ```
 
-use clap::{crate_version, Parser};
+use clap::{Parser, crate_version};
 use clap_verbosity_flag::log::Level;
 use clap_verbosity_flag::{InfoLevel, Verbosity};
 use hugr::envelope::EnvelopeError;
@@ -119,6 +119,7 @@ pub struct OtherArgs {
 
 impl OtherArgs {
     /// Test whether a `level` message should be output.
+    #[must_use]
     pub fn verbosity(&self, level: Level) -> bool {
         self.verbose.log_level_filter() >= level
     }

hugr-cli/src/main.rs

@@ -2,7 +2,7 @@
 
 use clap::Parser as _;
 
-use hugr_cli::{mermaid, validate, CliArgs};
+use hugr_cli::{CliArgs, mermaid, validate};
 
 use clap_verbosity_flag::log::Level;
 
@@ -22,7 +22,7 @@ fn main() {
             eprintln!("Unknown command");
             std::process::exit(1);
         }
-    };
+    }
 }
 
 /// Run the `validate` subcommand.
@@ -31,7 +31,7 @@ fn run_validate(mut args: validate::ValArgs) {
 
     if let Err(e) = result {
         if args.verbosity(Level::Error) {
-            eprintln!("{}", e);
+            eprintln!("{e}");
         }
         std::process::exit(1);
     }
@@ -43,7 +43,7 @@ fn run_mermaid(mut args: mermaid::MermaidArgs) {
 
     if let Err(e) = result {
         if args.other_args.verbosity(Level::Error) {
-            eprintln!("{}", e);
+            eprintln!("{e}");
         }
         std::process::exit(1);
     }

hugr-cli/src/mermaid.rs

@@ -4,11 +4,11 @@ use std::io::Write;
 use clap::Parser;
 use clap_verbosity_flag::log::Level;
 use clio::Output;
-use hugr::package::PackageValidationError;
 use hugr::HugrView;
+use hugr::package::PackageValidationError;
 
-use crate::hugr_io::HugrInputArgs;
 use crate::OtherArgs;
+use crate::hugr_io::HugrInputArgs;
 
 /// Dump the standard extensions.
 #[derive(Parser, Debug)]
@@ -39,9 +39,10 @@ pub struct MermaidArgs {
 impl MermaidArgs {
     /// Write the mermaid diagram to the output.
     pub fn run_print(&mut self) -> Result<(), crate::CliError> {
-        match self.input_args.hugr_json {
-            true => self.run_print_hugr(),
-            false => self.run_print_envelope(),
+        if self.input_args.hugr_json {
+            self.run_print_hugr()
+        } else {
+            self.run_print_envelope()
         }
     }
 
@@ -73,6 +74,7 @@ impl MermaidArgs {
     }
 
     /// Test whether a `level` message should be output.
+    #[must_use]
     pub fn verbosity(&self, level: Level) -> bool {
         self.other_args.verbosity(level)
     }

hugr-cli/src/validate.rs

@@ -30,28 +30,26 @@ pub const VALID_PRINT: &str = "HUGR valid!";
 impl ValArgs {
     /// Run the HUGR cli and validate against an extension registry.
     pub fn run(&mut self) -> Result<Vec<Hugr>, CliError> {
-        let result = match self.input_args.hugr_json {
-            true => {
-                let hugr = self.input_args.get_hugr()?;
-                hugr.validate()
-                    .map_err(PackageValidationError::Validation)?;
-                vec![hugr]
-            }
-            false => {
-                let package = self.input_args.get_package()?;
-                package.validate()?;
-                package.modules
-            }
+        let result = if self.input_args.hugr_json {
+            let hugr = self.input_args.get_hugr()?;
+            hugr.validate()
+                .map_err(PackageValidationError::Validation)?;
+            vec![hugr]
+        } else {
+            let package = self.input_args.get_package()?;
+            package.validate()?;
+            package.modules
         };
 
         if self.verbosity(Level::Info) {
-            eprintln!("{}", VALID_PRINT);
+            eprintln!("{VALID_PRINT}");
         }
 
         Ok(result)
     }
 
     /// Test whether a `level` message should be output.
+    #[must_use]
     pub fn verbosity(&self, level: Level) -> bool {
         self.other_args.verbosity(level)
     }

hugr-cli/tests/gen_extensions.rs

@@ -36,7 +36,7 @@ fn test_extension_dump(mut cmd: Command) {
         "collections/list.json",
     ];
     // check all paths exist
-    for path in expected_paths.iter() {
+    for path in &expected_paths {
         let full_path = temp_dir.join(path);
         assert!(full_path.exists());
     }

hugr-cli/tests/validate.rs

@@ -5,7 +5,7 @@
 #![cfg(all(test, not(miri)))]
 
 use assert_cmd::Command;
-use assert_fs::{fixture::FileWriteStr, NamedTempFile};
+use assert_fs::{NamedTempFile, fixture::FileWriteStr};
 use hugr::builder::{DFGBuilder, DataflowSubContainer, ModuleBuilder};
 use hugr::envelope::EnvelopeConfig;
 use hugr::package::Package;

hugr-core/src/builder.rs

@@ -5,17 +5,17 @@
 //! Depending on the type of HUGR you want to build, you may want to use one of
 //! the following builders:
 //!
-//! - [ModuleBuilder]: For building a module with function declarations and
+//! - [`ModuleBuilder`]: For building a module with function declarations and
 //!   definitions.
-//! - [DFGBuilder]: For building a dataflow graph.
-//! - [FunctionBuilder]: A `DFGBuilder` specialised in defining functions with a
+//! - [`DFGBuilder`]: For building a dataflow graph.
+//! - [`FunctionBuilder`]: A `DFGBuilder` specialised in defining functions with a
 //!   dataflow graph.
-//! - [CFGBuilder]: For building a control flow graph.
-//! - [ConditionalBuilder]: For building a conditional node.
-//! - [TailLoopBuilder]: For building a tail-loop node.
+//! - [`CFGBuilder`]: For building a control flow graph.
+//! - [`ConditionalBuilder`]: For building a conditional node.
+//! - [`TailLoopBuilder`]: For building a tail-loop node.
 //!
-//! Additionally, the [CircuitBuilder] provides an alternative to the
-//! [DFGBuilder] when working with circuits, where some inputs of operations directly
+//! Additionally, the [`CircuitBuilder`] provides an alternative to the
+//! [`DFGBuilder`] when working with circuits, where some inputs of operations directly
 //! correspond to some outputs and operations can be directly appended using
 //! unit indices.
 //!
@@ -87,8 +87,8 @@
 //! ```
 use thiserror::Error;
 
-use crate::extension::simple_op::OpLoadError;
 use crate::extension::SignatureError;
+use crate::extension::simple_op::OpLoadError;
 use crate::hugr::ValidationError;
 use crate::ops::handle::{BasicBlockID, CfgID, ConditionalID, DfgID, FuncID, TailLoopID};
 use crate::ops::{NamedOp, OpType};
@@ -122,12 +122,12 @@ pub use conditional::{CaseBuilder, ConditionalBuilder};
 mod circuit;
 pub use circuit::{CircuitBuildError, CircuitBuilder};
 
-/// Return a FunctionType with the same input and output types (specified).
+/// Return a `FunctionType` with the same input and output types (specified).
 pub fn endo_sig(types: impl Into<TypeRow>) -> Signature {
     Signature::new_endo(types)
 }
 
-/// Return a FunctionType with the specified input and output types.
+/// Return a `FunctionType` with the specified input and output types.
 pub fn inout_sig(inputs: impl Into<TypeRow>, outputs: impl Into<TypeRow>) -> Signature {
     Signature::new(inputs, outputs)
 }
@@ -139,8 +139,8 @@ pub enum BuildError {
     /// The constructed HUGR is invalid.
     #[error("The constructed HUGR is invalid: {0}.")]
     InvalidHUGR(#[from] ValidationError<Node>),
-    /// SignatureError in trying to construct a node (differs from
-    /// [ValidationError::SignatureError] in that we could not construct a node to report about)
+    /// `SignatureError` in trying to construct a node (differs from
+    /// [`ValidationError::SignatureError`] in that we could not construct a node to report about)
     #[error(transparent)]
     SignatureError(#[from] SignatureError),
     /// Tried to add a malformed [Const]
@@ -152,8 +152,10 @@ pub enum BuildError {
     #[error("CFG entry node already built for CFG node: {0}.")]
     EntryBuiltError(Node),
     /// We don't allow creating `BasicBlockBuilder<Hugr>`s when the sum-rows
-    /// are not homogeneous. Use a CFGBuilder and create a valid graph instead.
-    #[error("Cannot initialize hugr for a BasicBlockBuilder with complex sum-rows. Use a CFGBuilder instead.")]
+    /// are not homogeneous. Use a `CFGBuilder` and create a valid graph instead.
+    #[error(
+        "Cannot initialize hugr for a BasicBlockBuilder with complex sum-rows. Use a CFGBuilder instead."
+    )]
     BasicBlockTooComplex,
     /// Node was expected to have a certain type but was found to not.
     #[error("Node with index {node} does not have type {op_desc} as expected.")]
@@ -179,7 +181,7 @@ pub enum BuildError {
     #[error("Wire not found in Hugr: {0}.")]
     WireNotFound(Wire),
 
-    /// Error in CircuitBuilder
+    /// Error in `CircuitBuilder`
     #[error("Error in CircuitBuilder: {0}.")]
     CircuitError(#[from] circuit::CircuitBuildError),
 
@@ -222,7 +224,9 @@ pub enum BuilderWiringError {
         src_offset: Port,
     },
     /// The ancestors of an inter-graph edge are not related.
-    #[error("Cannot connect an inter-graph edge between unrelated nodes. Tried connecting {src} ({src_offset}) with {dst} ({dst_offset}).")]
+    #[error(
+        "Cannot connect an inter-graph edge between unrelated nodes. Tried connecting {src} ({src_offset}) with {dst} ({dst_offset})."
+    )]
     #[allow(missing_docs)]
     NoRelationIntergraph {
         src: Node,
@@ -231,7 +235,9 @@ pub enum BuilderWiringError {
         dst_offset: Port,
     },
     /// Inter-Graph edges can only carry copyable data.
-    #[error("Inter-graph edges cannot carry non-copyable data {typ}. Tried connecting {src} ({src_offset}) with {dst} ({dst_offset}).")]
+    #[error(
+        "Inter-graph edges cannot carry non-copyable data {typ}. Tried connecting {src} ({src_offset}) with {dst} ({dst_offset})."
+    )]
     #[allow(missing_docs)]
     NonCopyableIntergraph {
         src: Node,
@@ -246,12 +252,12 @@ pub enum BuilderWiringError {
 pub(crate) mod test {
     use rstest::fixture;
 
+    use crate::Hugr;
     use crate::extension::prelude::{bool_t, usize_t};
-    use crate::hugr::{views::HugrView, HugrMut};
+    use crate::hugr::{HugrMut, views::HugrView};
     use crate::ops;
     use crate::package::Package;
     use crate::types::{PolyFuncType, Signature};
-    use crate::Hugr;
 
     use super::handle::BuildHandle;
     use super::{