Auto format let-else block (#10214)

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rustfmt 1.6.0 has added support for formatting [let-else
statements](https://doc.rust-lang.org/rust-by-example/flow_control/let_else.html)

See https://github.com/rust-lang/rustfmt/blob/master/CHANGELOG.md#added

# User-Facing Changes
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helps us keep track of breaking changes. -->

# Tests + Formatting
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crates/nu-cmd-lang/src/core_commands/match_.rs

@@ -53,8 +53,9 @@ impl Command for Match {
                     }
 
                     let guard_matches = if let Some(guard) = &match_.0.guard {
-                        let Value::Bool { val, .. } = eval_expression(engine_state, stack, guard)? else {
+                        let Value::Bool { val, .. } = eval_expression(engine_state, stack, guard)?
-                            return Err(ShellError::MatchGuardNotBool { span: guard.span});
+                        else {
+                            return Err(ShellError::MatchGuardNotBool { span: guard.span });
                         };
 
                         val

crates/nu-cmd-lang/src/core_commands/use_.rs

@@ -52,7 +52,8 @@ This command is a parser keyword. For details, check:
         let Some(Expression {
             expr: Expr::ImportPattern(import_pattern),
             ..
-        }) = call.get_parser_info("import_pattern") else {
+        }) = call.get_parser_info("import_pattern")
+        else {
             return Err(ShellError::GenericError(
                 "Unexpected import".into(),
                 "import pattern not supported".into(),

crates/nu-command/src/strings/parse.rs

@@ -339,17 +339,19 @@ impl Iterator for ParseStreamer {
                 }
             }
 
-            let Some(v) = self.stream.next() else { return None };
+            let Some(v) = self.stream.next() else {
+                return None;
+            };
 
             let Ok(s) = v.as_string() else {
-                return Some(Value::error (
+                return Some(Value::error(
                     ShellError::PipelineMismatch {
                         exp_input_type: "string".into(),
                         dst_span: self.span,
                         src_span: v.span(),
                     },
-                     v.span(),
+                    v.span(),
-                ))
+                ));
             };
 
             let parsed = stream_helper(
@@ -412,8 +414,8 @@ impl Iterator for ParseStreamerExternal {
                     dst_span: self.span,
                     src_span: self.span,
                 },
-               self.span,
+                self.span,
-            ))
+            ));
         };
 
         stream_helper(

crates/nu-parser/src/parse_keywords.rs

@@ -3510,7 +3510,7 @@ pub fn parse_register(working_set: &mut StateWorkingSet, spans: &[Span]) -> Pipe
                 value_as_string(val, expr.span).map_err(|err| err.wrap(working_set, call.head))?;
 
             let Some(path) = find_in_dirs(&filename, working_set, &cwd, PLUGIN_DIRS_VAR) else {
-                return Err(ParseError::RegisteredFileNotFound(filename, expr.span))
+                return Err(ParseError::RegisteredFileNotFound(filename, expr.span));
             };
 
             if path.exists() && path.is_file() {

crates/nu-parser/src/parser.rs

@@ -2822,7 +2822,7 @@ fn parse_collection_shape(
         while idx < tokens.len() {
             let TokenContents::Item = tokens[idx].contents else {
                 working_set.error(key_error(tokens[idx].span));
-                return mk_shape(vec![])
+                return mk_shape(vec![]);
             };
 
             let key_bytes = working_set.get_span_contents(tokens[idx].span).to_vec();
@@ -2831,7 +2831,9 @@ fn parse_collection_shape(
                 continue;
             }
 
-            let Some(key) = parse_value(working_set, tokens[idx].span, &SyntaxShape::String).as_string() else {
+            let Some(key) =
+                parse_value(working_set, tokens[idx].span, &SyntaxShape::String).as_string()
+            else {
                 working_set.error(key_error(tokens[idx].span));
                 return mk_shape(vec![]);
             };
@@ -4026,7 +4028,11 @@ fn parse_table_expression(working_set: &mut StateWorkingSet, span: Span) -> Expr
     }
 
     let head = {
-        let Expression { expr: Expr::List(vals), .. } = head else {
+        let Expression {
+            expr: Expr::List(vals),
+            ..
+        } = head
+        else {
             unreachable!("head must be a list by now")
         };
 
@@ -4058,7 +4064,8 @@ fn parse_table_expression(working_set: &mut StateWorkingSet, span: Span) -> Expr
                         expr: Expr::List(item),
                         span,
                         ..
-                    } = ls  else {
+                    } = ls
+                    else {
                         unreachable!("the item must be a list")
                     };
 

crates/nu-protocol/src/value/range.rs

@@ -210,9 +210,10 @@ impl Iterator for RangeIterator {
             self.curr.partial_cmp(&self.end)
         };
 
-        let Some(ordering) = ordering  else {
+        let Some(ordering) = ordering else {
             self.done = true;
-            return Some(Value::error(ShellError::CannotCreateRange { span: self.span },
+            return Some(Value::error(
+                ShellError::CannotCreateRange { span: self.span },
                 self.span,
             ));
         };