Merge #128: another round of new clippy lints

0fc8f4a clippy: turn on `map_unwrap_or` lint (Andrew Poelstra)
bd22858 clippy: turn on manual_let_else lint (Andrew Poelstra)
ec358cc clippy: turn on manual_assert lint (Andrew Poelstra)
b2767a4 clippy: move statements after items (Andrew Poelstra)
8cd383b clippy: turn on ignored_unit_patterns lint (Andrew Poelstra)
3725f92 clippy: remove match_on_vec_items (Andrew Poelstra)
fd143db clippy: warn on `doc_markdown` (Andrew Poelstra)

Pull request description:

  Mostly style. Does find one real issue with our docs.

ACKs for top commit:
  uncomputable:
    ACK 0fc8f4a

Tree-SHA512: acd29dd37bccda751562ed3aea64f72aa8f7796d933b60a39f25eca0472fd83744779f5338feadc1c16e5849ce616154874878b9c2fef28e4e7f369839109f33

Author: apoelstra

Cargo.toml

@@ -44,6 +44,7 @@ exclude = ["fuzz", "bitcoind-tests"]
 large_enum_variant = "allow" # docs say "measure before paying attention to this"; why is it on by default??
 similar_names = "allow" # Too many (subjectively) false positives.
 uninlined_format_args = "allow" # This is a subjective style choice.
+indexing_slicing = "allow" # Too many false positives ... would be cool though
 match_bool = "allow" # Adds extra indentation and LOC.
 match_same_arms = "allow" # Collapses things that are conceptually unrelated to each other.
 must_use_candidate = "allow" # Useful for audit but many false positives.
@@ -65,7 +66,7 @@ cloned_instead_of_copied = "warn"
 copy_iterator = "warn"
 default_trait_access = "warn"
 doc_link_with_quotes = "warn"
-doc_markdown = "allow"
+doc_markdown = "warn"
 empty_enum = "warn"
 enum_glob_use = "allow"
 expl_impl_clone_on_copy = "warn"
@@ -78,7 +79,7 @@ float_cmp = "warn"
 fn_params_excessive_bools = "warn"
 from_iter_instead_of_collect = "warn"
 if_not_else = "warn"
-ignored_unit_patterns = "allow"
+ignored_unit_patterns = "warn"
 implicit_clone = "warn"
 implicit_hasher = "warn"
 inconsistent_struct_constructor = "warn"
@@ -87,7 +88,7 @@ inefficient_to_string = "allow"
 inline_always = "warn"
 into_iter_without_iter = "warn"
 invalid_upcast_comparisons = "warn"
-items_after_statements = "allow"
+items_after_statements = "warn"
 iter_filter_is_ok = "warn"
 iter_filter_is_some = "warn"
 iter_not_returning_iterator = "warn"
@@ -98,16 +99,15 @@ large_stack_arrays = "warn"
 large_types_passed_by_value = "warn"
 linkedlist = "warn"
 macro_use_imports = "warn"
-manual_assert = "allow"
+manual_assert = "warn"
 manual_instant_elapsed = "warn"
 manual_is_power_of_two = "warn"
 manual_is_variant_and = "warn"
-manual_let_else = "allow"
+manual_let_else = "warn"
 manual_ok_or = "warn"
 manual_string_new = "warn"
 many_single_char_names = "warn"
-map_unwrap_or = "allow"
-match_on_vec_items = "warn"
+map_unwrap_or = "warn"
 match_wild_err_arm = "warn"
 match_wildcard_for_single_variants = "allow"
 maybe_infinite_iter = "warn"

src/compile.rs

@@ -438,19 +438,6 @@ impl Call {
 /// takes the list of type `E^(<2^n)` and an initial accumulator of type `A`,
 /// and it produces the final accumulator of type `A`.
 fn list_fold(bound: NonZeroPow2Usize, f: &ProgNode) -> Result<ProgNode, simplicity::types::Error> {
-    /* f_0 :  E × A → A
-     * f_0 := f
-     */
-    let mut f_array = f.clone();
-
-    /* (fold f)_1 :  E^<2 × A → A
-     * (fold f)_1 := case IH f_0
-     */
-    let ctx = f.inference_context();
-    let ioh = ProgNode::i().h(ctx);
-    let mut f_fold = ProgNode::case(ioh.as_ref(), &f_array)?;
-    let mut i = NonZeroPow2Usize::TWO;
-
     fn next_f_array(f_array: &ProgNode) -> Result<ProgNode, simplicity::types::Error> {
         /* f_(n + 1) :  E^(2^(n + 1)) × A → A
          * f_(n + 1) := OIH ▵ (OOH ▵ IH; f_n); f_n
@@ -487,6 +474,19 @@ fn list_fold(bound: NonZeroPow2Usize, f: &ProgNode) -> Result<ProgNode, simplici
             .map(PairBuilder::build)
     }
 
+    /* f_0 :  E × A → A
+     * f_0 := f
+     */
+    let mut f_array = f.clone();
+
+    /* (fold f)_1 :  E^<2 × A → A
+     * (fold f)_1 := case IH f_0
+     */
+    let ctx = f.inference_context();
+    let ioh = ProgNode::i().h(ctx);
+    let mut f_fold = ProgNode::case(ioh.as_ref(), &f_array)?;
+    let mut i = NonZeroPow2Usize::TWO;
+
     while i < bound {
         f_array = next_f_array(&f_array)?;
         f_fold = next_f_fold(&f_array, &f_fold)?;
@@ -617,8 +617,7 @@ impl Match {
                 .pattern()
                 .as_variable()
                 .cloned()
-                .map(Pattern::Identifier)
-                .unwrap_or(Pattern::Ignore),
+                .map_or(Pattern::Ignore, Pattern::Identifier),
         );
         let left = self.left().expression().compile(scope)?;
         scope.pop_scope();
@@ -629,8 +628,7 @@ impl Match {
                 .pattern()
                 .as_variable()
                 .cloned()
-                .map(Pattern::Identifier)
-                .unwrap_or(Pattern::Ignore),
+                .map_or(Pattern::Ignore, Pattern::Identifier),
         );
         let right = self.right().expression().compile(scope)?;
         scope.pop_scope();

src/error.rs

@@ -35,14 +35,11 @@ impl Position {
     ///
     /// Line or column are zero.
     pub const fn new(line: usize, col: usize) -> Self {
-        if line == 0 {
-            panic!("Line must not be zero");
-        }
+        // assert_ne not available in constfn
+        assert!(line != 0, "line must not be zero",);
         // Safety: Checked above
         let line = unsafe { NonZeroUsize::new_unchecked(line) };
-        if col == 0 {
-            panic!("Column must not be zero");
-        }
+        assert!(col != 0, "column must not be zero",);
         // Safety: Checked above
         let col = unsafe { NonZeroUsize::new_unchecked(col) };
         Self { line, col }
@@ -236,7 +233,7 @@ impl fmt::Display for RichError {
                 writeln!(f, "{:width$} |", " ", width = line_num_width)?;
 
                 let mut lines = file.lines().skip(start_line_index).peekable();
-                let start_line_len = lines.peek().map(|l| l.len()).unwrap_or(0);
+                let start_line_len = lines.peek().map_or(0, |l| l.len());
 
                 for (relative_line_index, line_str) in lines.take(n_spanned_lines).enumerate() {
                     let line_num = start_line_index + relative_line_index + 1;

src/lib.rs

@@ -238,7 +238,7 @@ macro_rules! impl_eq_hash {
 /// the initial budget. The budget prevents the generated structure from becoming too deep, which
 /// could cause issues in the code that processes these structures.
 ///
-/// https://github.com/rust-fuzz/arbitrary/issues/78
+/// <https://github.com/rust-fuzz/arbitrary/issues/78>
 #[cfg(feature = "arbitrary")]
 trait ArbitraryRec: Sized {
     /// Generate a recursive structure from unstructured data.
@@ -426,7 +426,7 @@ mod tests {
 
         pub fn assert_run_success(self) {
             match self.run() {
-                Ok(_) => {}
+                Ok(()) => {}
                 Err(error) => panic!("Unexpected error: {error}"),
             }
         }
@@ -620,9 +620,10 @@ fn main() {
         ) {
             Ok(_) => panic!("Accepted faulty program"),
             Err(error) => {
-                if !error.contains("Expected expression of type `bool`, found type `()`") {
-                    panic!("Unexpected error: {error}")
-                }
+                assert!(
+                    error.contains("Expected expression of type `bool`, found type `()`"),
+                    "Unexpected error: {error}",
+                );
             }
         }
     }

src/witness.rs

@@ -114,9 +114,8 @@ impl WitnessValues {
     /// witnesses will be pruned and which won't be pruned. This check skips unassigned witnesses.
     pub fn is_consistent(&self, witness_types: &WitnessTypes) -> Result<(), Error> {
         for name in self.0.keys() {
-            let declared_ty = match witness_types.get(name) {
-                Some(ty) => ty,
-                None => continue,
+            let Some(declared_ty) = witness_types.get(name) else {
+                continue;
             };
             let assigned_ty = self.0[name].ty();
             if assigned_ty != declared_ty {