Call pattern formatting (#6594)

crates/ruff_python_formatter/resources/test/fixtures/ruff/statement/match.py

@@ -108,3 +108,36 @@ match long_lines:
         bbbbbbbbaaaaaahhhh == 2
     ):  # another comment
         pass
+
+
+match pattern_comments:
+    case (
+    only_trailing  # trailing 1
+    # trailing 2
+# trailing 3
+    ):
+        pass
+
+
+match pattern_comments:
+    case (  # leading
+    only_leading
+    ):
+        pass
+
+
+match pattern_comments:
+    case (
+    # leading
+    leading_and_trailing  # trailing 1
+    # trailing 2
+# trailing 3
+    ):
+        pass
+
+
+match pattern_comments:
+    case (
+    no_comments
+    ):
+        pass

crates/ruff_python_formatter/src/comments/mod.rs

@@ -388,6 +388,7 @@ impl<'a> Comments<'a> {
     }
 
     /// Returns an iterator over the [leading](self#leading-comments) and [trailing comments](self#trailing-comments) of `node`.
+    #[allow(unused)]
     pub(crate) fn leading_trailing_comments<T>(
         &self,
         node: T,

crates/ruff_python_formatter/src/lib.rs

@@ -152,40 +152,6 @@ pub fn format_node<'a>(
     Ok(formatted)
 }
 
-pub(crate) struct NotYetImplemented<'a>(AnyNodeRef<'a>);
-
-/// Formats a placeholder for nodes that have not yet been implemented
-pub(crate) fn not_yet_implemented<'a, T>(node: T) -> NotYetImplemented<'a>
-where
-    T: Into<AnyNodeRef<'a>>,
-{
-    NotYetImplemented(node.into())
-}
-
-impl Format<PyFormatContext<'_>> for NotYetImplemented<'_> {
-    fn fmt(&self, f: &mut PyFormatter) -> FormatResult<()> {
-        let text = std::format!("NOT_YET_IMPLEMENTED_{:?}", self.0.kind());
-
-        f.write_element(FormatElement::Tag(Tag::StartVerbatim(
-            tag::VerbatimKind::Verbatim {
-                length: text.text_len(),
-            },
-        )))?;
-
-        f.write_element(FormatElement::DynamicText {
-            text: Box::from(text),
-        })?;
-
-        f.write_element(FormatElement::Tag(Tag::EndVerbatim))?;
-
-        f.context()
-            .comments()
-            .mark_verbatim_node_comments_formatted(self.0);
-
-        Ok(())
-    }
-}
-
 pub(crate) struct NotYetImplementedCustomText<'a> {
     text: &'static str,
     node: AnyNodeRef<'a>,

crates/ruff_python_formatter/src/other/match_case.rs

@@ -1,10 +1,12 @@
-use ruff_formatter::{write, Buffer, FormatResult};
-use ruff_python_ast::MatchCase;
+use ruff_formatter::{format_args, write, Buffer, FormatResult};
+use ruff_python_ast::{MatchCase, Pattern, Ranged};
+use ruff_python_trivia::{SimpleTokenKind, SimpleTokenizer};
+use ruff_text_size::TextRange;
 
-use crate::comments::{trailing_comments, SourceComment};
-use crate::not_yet_implemented_custom_text;
+use crate::comments::{leading_comments, trailing_comments, SourceComment};
+use crate::expression::parentheses::parenthesized;
 use crate::prelude::*;
-use crate::{FormatNodeRule, PyFormatter};
+use crate::{FormatError, FormatNodeRule, PyFormatter};
 
 #[derive(Default)]
 pub struct FormatMatchCase;
@@ -21,25 +23,21 @@ impl FormatNodeRule<MatchCase> for FormatMatchCase {
         let comments = f.context().comments().clone();
         let dangling_item_comments = comments.dangling_comments(item);
 
-        write!(
-            f,
-            [
-                text("case"),
-                space(),
-                format_with(|f: &mut PyFormatter| {
-                    let comments = f.context().comments();
-
-                    for comment in comments.leading_trailing_comments(pattern) {
-                        // This is a lie, but let's go with it.
-                        comment.mark_formatted();
+        write!(f, [text("case"), space()])?;
+        let leading_pattern_comments = comments.leading_comments(pattern);
+        if !leading_pattern_comments.is_empty() {
+            parenthesized(
+                "(",
+                &format_args![leading_comments(leading_pattern_comments), pattern.format()],
+                ")",
+            )
+            .fmt(f)?;
+        } else if is_match_case_pattern_parenthesized(item, pattern, f.context())? {
+            parenthesized("(", &pattern.format(), ")").fmt(f)?;
+        } else {
+            pattern.format().fmt(f)?;
         }
 
-                    // Replace the whole `format_with` with `pattern.format()` once pattern formatting is implemented.
-                    not_yet_implemented_custom_text("NOT_YET_IMPLEMENTED_Pattern", pattern).fmt(f)
-                }),
-            ]
-        )?;
-
         if let Some(guard) = guard {
             write!(f, [space(), text("if"), space(), guard.format()])?;
         }
@@ -63,3 +61,33 @@ impl FormatNodeRule<MatchCase> for FormatMatchCase {
         Ok(())
     }
 }
+
+fn is_match_case_pattern_parenthesized(
+    case: &MatchCase,
+    pattern: &Pattern,
+    context: &PyFormatContext,
+) -> FormatResult<bool> {
+    let mut tokenizer = SimpleTokenizer::new(
+        context.source(),
+        TextRange::new(case.range().start(), pattern.range().start()),
+    )
+    .skip_trivia();
+
+    let case_keyword = tokenizer.next().ok_or(FormatError::syntax_error(
+        "Expected a `case` keyword, didn't find any token",
+    ))?;
+
+    debug_assert_eq!(
+        case_keyword.kind(),
+        SimpleTokenKind::Case,
+        "Expected `case` keyword but at {case_keyword:?}"
+    );
+
+    match tokenizer.next() {
+        Some(left_paren) => {
+            debug_assert_eq!(left_paren.kind(), SimpleTokenKind::LParen);
+            Ok(true)
+        }
+        None => Ok(false),
+    }
+}

crates/ruff_python_formatter/src/pattern/pattern_match_as.rs

@@ -1,12 +1,19 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchAs;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchAs;
 
 impl FormatNodeRule<PatternMatchAs> for FormatPatternMatchAs {
     fn fmt_fields(&self, item: &PatternMatchAs, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "x as NOT_YET_IMPLEMENTED_PatternMatchAs",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_class.rs

@@ -1,12 +1,19 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchClass;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchClass;
 
 impl FormatNodeRule<PatternMatchClass> for FormatPatternMatchClass {
     fn fmt_fields(&self, item: &PatternMatchClass, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0)",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_mapping.rs

@@ -1,12 +1,19 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchMapping;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchMapping;
 
 impl FormatNodeRule<PatternMatchMapping> for FormatPatternMatchMapping {
     fn fmt_fields(&self, item: &PatternMatchMapping, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "{\"NOT_YET_IMPLEMENTED_PatternMatchMapping\": _, 2: _}",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_or.rs

@@ -1,12 +1,19 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchOr;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchOr;
 
 impl FormatNodeRule<PatternMatchOr> for FormatPatternMatchOr {
     fn fmt_fields(&self, item: &PatternMatchOr, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "NOT_YET_IMPLEMENTED_PatternMatchOf | (y)",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_sequence.rs

@@ -1,12 +1,19 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchSequence;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchSequence;
 
 impl FormatNodeRule<PatternMatchSequence> for FormatPatternMatchSequence {
     fn fmt_fields(&self, item: &PatternMatchSequence, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "[NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_singleton.rs

@@ -1,12 +1,13 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchSingleton;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchSingleton;
 
 impl FormatNodeRule<PatternMatchSingleton> for FormatPatternMatchSingleton {
     fn fmt_fields(&self, item: &PatternMatchSingleton, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(f, [not_yet_implemented_custom_text("None", item)])
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_star.rs

@@ -1,12 +1,19 @@
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
 use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchStar;
 
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+
 #[derive(Default)]
 pub struct FormatPatternMatchStar;
 
 impl FormatNodeRule<PatternMatchStar> for FormatPatternMatchStar {
     fn fmt_fields(&self, item: &PatternMatchStar, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "*NOT_YET_IMPLEMENTED_PatternMatchStar",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/pattern/pattern_match_value.rs

@@ -1,14 +1,19 @@
+use ruff_formatter::{write, Buffer, FormatResult};
 use ruff_python_ast::PatternMatchValue;
 
-use ruff_formatter::{write, Buffer, FormatResult};
-
-use crate::{not_yet_implemented, FormatNodeRule, PyFormatter};
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
 
 #[derive(Default)]
 pub struct FormatPatternMatchValue;
 
 impl FormatNodeRule<PatternMatchValue> for FormatPatternMatchValue {
     fn fmt_fields(&self, item: &PatternMatchValue, f: &mut PyFormatter) -> FormatResult<()> {
-        write!(f, [not_yet_implemented(item)])
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "\"NOT_YET_IMPLEMENTED_PatternMatchValue\"",
+                item
+            )]
+        )
     }
 }

crates/ruff_python_formatter/src/statement/stmt_match.rs

@@ -51,11 +51,11 @@ impl FormatNodeRule<StmtMatch> for FormatStmtMatch {
             write!(
                 f,
                 [block_indent(&format_args!(
-                    &leading_alternate_branch_comments(
+                    leading_alternate_branch_comments(
                         comments.leading_comments(case),
                         last_case.body.last(),
                     ),
-                    &case.format()
+                    case.format()
                 ))]
             )?;
             last_case = case;

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_310__pattern_matching_complex.py.snap

@@ -156,191 +156,190 @@ match x:
 ```diff
 --- Black
 +++ Ruff
-@@ -2,143 +2,143 @@
+@@ -2,105 +2,105 @@
  
  # case black_test_patma_098
  match x:
 -    case -0j:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
  # case black_test_patma_142
  match x:
 -    case bytes(z):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          y = 0
  # case black_test_patma_073
  match x:
 -    case 0 if 0:
-+    case NOT_YET_IMPLEMENTED_Pattern if 0:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if 0:
          y = 0
 -    case 0 if 1:
-+    case NOT_YET_IMPLEMENTED_Pattern if 1:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if 1:
          y = 1
  # case black_test_patma_006
  match 3:
 -    case 0 | 1 | 2 | 3:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          x = True
  # case black_test_patma_049
  match x:
 -    case [0, 1] | [1, 0]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          y = 0
  # case black_check_sequence_then_mapping
  match x:
 -    case [*_]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          return "seq"
 -    case {}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          return "map"
  # case black_test_patma_035
  match x:
 -    case {0: [1, 2, {}]}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          y = 0
 -    case {0: [1, 2, {}] | True} | {1: [[]]} | {0: [1, 2, {}]} | [] | "X" | {}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          y = 1
 -    case []:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 2
  # case black_test_patma_107
  match x:
 -    case 0.25 + 1.75j:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
  # case black_test_patma_097
  match x:
 -    case -0j:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
  # case black_test_patma_007
  match 4:
 -    case 0 | 1 | 2 | 3:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          x = True
  # case black_test_patma_154
  match x:
 -    case 0 if x:
-+    case NOT_YET_IMPLEMENTED_Pattern if x:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if x:
          y = 0
  # case black_test_patma_134
  match x:
 -    case {1: 0}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          y = 0
 -    case {0: 0}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          y = 1
 -    case {**z}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          y = 2
  # case black_test_patma_185
  match Seq():
 -    case [*_]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 0
  # case black_test_patma_063
  match x:
 -    case 1:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
 -    case 1:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 1
  # case black_test_patma_248
  match x:
 -    case {"foo": bar}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          y = bar
  # case black_test_patma_019
  match (0, 1, 2):
 -    case [0, 1, *x, 2]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 0
  # case black_test_patma_052
  match x:
 -    case [0]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 0
 -    case [1, 0] if (x := x[:0]):
-+    case NOT_YET_IMPLEMENTED_Pattern if (x := x[:0]):
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2] if (x := x[:0]):
          y = 1
 -    case [1, 0]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 2
  # case black_test_patma_191
  match w:
 -    case [x, y, *_]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          z = 0
  # case black_test_patma_110
  match x:
 -    case -0.25 - 1.75j:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
  # case black_test_patma_151
  match (x,):
 -    case [y]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          z = 0
  # case black_test_patma_114
  match x:
 -    case A.B.C.D:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
  # case black_test_patma_232
  match x:
--    case None:
-+    case NOT_YET_IMPLEMENTED_Pattern:
+@@ -108,37 +108,37 @@
          y = 0
  # case black_test_patma_058
  match x:
 -    case 0:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 0
  # case black_test_patma_233
  match x:
 -    case False:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case None:
          y = 0
  # case black_test_patma_078
  match x:
 -    case []:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 0
 -    case [""]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 1
 -    case "":
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
          y = 2
  # case black_test_patma_156
  match x:
 -    case z:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          y = 0
  # case black_test_patma_189
  match w:
 -    case [x, y, *rest]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          z = 0
  # case black_test_patma_042
  match x:
 -    case (0 as z) | (1 as z) | (2 as z) if z == x % 2:
-+    case NOT_YET_IMPLEMENTED_Pattern if z == x % 2:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y) if z == x % 2:
          y = 0
  # case black_test_patma_034
  match x:
 -    case {0: [1, 2, {}]}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          y = 0
 -    case {0: [1, 2, {}] | False} | {1: [[]]} | {0: [1, 2, {}]} | [] | "X" | {}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          y = 1
 -    case []:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          y = 2
 ```
 
@@ -351,145 +350,145 @@ match x:
 
 # case black_test_patma_098
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
 # case black_test_patma_142
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         y = 0
 # case black_test_patma_073
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern if 0:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if 0:
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern if 1:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if 1:
         y = 1
 # case black_test_patma_006
 match 3:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         x = True
 # case black_test_patma_049
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         y = 0
 # case black_check_sequence_then_mapping
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         return "seq"
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         return "map"
 # case black_test_patma_035
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         y = 1
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 2
 # case black_test_patma_107
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
 # case black_test_patma_097
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
 # case black_test_patma_007
 match 4:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         x = True
 # case black_test_patma_154
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern if x:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if x:
         y = 0
 # case black_test_patma_134
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         y = 1
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         y = 2
 # case black_test_patma_185
 match Seq():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 0
 # case black_test_patma_063
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 1
 # case black_test_patma_248
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         y = bar
 # case black_test_patma_019
 match (0, 1, 2):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 0
 # case black_test_patma_052
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern if (x := x[:0]):
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2] if (x := x[:0]):
         y = 1
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 2
 # case black_test_patma_191
 match w:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         z = 0
 # case black_test_patma_110
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
 # case black_test_patma_151
 match (x,):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         z = 0
 # case black_test_patma_114
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
 # case black_test_patma_232
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case None:
         y = 0
 # case black_test_patma_058
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 0
 # case black_test_patma_233
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case None:
         y = 0
 # case black_test_patma_078
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 1
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         y = 2
 # case black_test_patma_156
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         y = 0
 # case black_test_patma_189
 match w:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         z = 0
 # case black_test_patma_042
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern if z == x % 2:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y) if z == x % 2:
         y = 0
 # case black_test_patma_034
 match x:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         y = 0
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         y = 1
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         y = 2
 ```
 

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_310__pattern_matching_extras.py.snap

@@ -136,16 +136,16 @@ match bar1:
  
  match something:
 -    case [a as b]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          print(b)
 -    case [a as b, c, d, e as f]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          print(f)
 -    case Point(a as b):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          print(b)
 -    case Point(int() as x, int() as y):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          print(x, y)
  
  
@@ -154,29 +154,29 @@ match bar1:
  
  match re.match(case):
 -    case type("match", match):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          pass
 -    case match:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          pass
  
  
  def func(match: case, case: match) -> case:
      match Something():
 -        case func(match, case):
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
              ...
 -        case another:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
              ...
  
  
  match maybe, multiple:
 -    case perhaps, 5:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
 -    case perhaps, 6,:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
  
  
@@ -186,22 +186,22 @@ match bar1:
 +    more := (than, one),
 +    indeed,
 +):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
 -    case [[5], (6)], [7],:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
 -    case _:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          pass
  
  
  match a, *b, c:
 -    case [*_]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          assert "seq" == _
 -    case {}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          assert "map" == b
  
  
@@ -215,27 +215,27 @@ match bar1:
 -            loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong
 -        ),
 -    ):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          pass
  
 -    case [a as match]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
  
 -    case case:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          pass
  
  
  match match:
 -    case case:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          pass
  
  
  match a, *b(), c:
 -    case d, *f, g:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
  
  
@@ -244,33 +244,33 @@ match bar1:
 -        "key": key as key_1,
 -        "password": PASS.ONE | PASS.TWO | PASS.THREE as password,
 -    }:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          pass
 -    case {"maybe": something(complicated as this) as that}:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
          pass
  
  
  match something:
 -    case 1 as a:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          pass
  
 -    case 2 as b, 3 as c:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
  
 -    case 4 as d, (5 as e), (6 | 7 as g), *h:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
  
  
  match bar1:
 -    case Foo(aa=Callable() as aa, bb=int()):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          print(bar1.aa, bar1.bb)
 -    case _:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          print("no match", "\n")
  
  
@@ -278,7 +278,7 @@ match bar1:
 -    case Foo(
 -        normal=x, perhaps=[list, {"x": d, "y": 1.0}] as y, otherwise=something, q=t as u
 -    ):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          pass
 ```
 
@@ -288,13 +288,13 @@ match bar1:
 import match
 
 match something:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         print(b)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         print(f)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         print(b)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         print(x, y)
 
 
@@ -302,24 +302,24 @@ match = 1
 case: int = re.match(something)
 
 match re.match(case):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
 
 def func(match: case, case: match) -> case:
     match Something():
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
             ...
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
             ...
 
 
 match maybe, multiple:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
 
@@ -327,18 +327,18 @@ match (
     more := (than, one),
     indeed,
 ):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
 
 match a, *b, c:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         assert "seq" == _
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         assert "map" == b
 
 
@@ -349,53 +349,53 @@ match match(
     ),
     case,
 ):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
 
 match match:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
 
 match a, *b(), c:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
 
 match something:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case {"NOT_YET_IMPLEMENTED_PatternMatchMapping": _, 2: _}:
         pass
 
 
 match something:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
 
 match bar1:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         print(bar1.aa, bar1.bb)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         print("no match", "\n")
 
 
 match bar1:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         pass
 ```
 

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_310__pattern_matching_generic.py.snap

@@ -124,10 +124,10 @@ with match() as match:
  
      match match:
 -        case case:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
              match match:
 -                case case:
-+                case NOT_YET_IMPLEMENTED_Pattern:
++                case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
                      pass
  
      if all(version.is_python2() for version in target_versions):
@@ -136,7 +136,7 @@ with match() as match:
          x = False
          match x:
 -            case bool(z):
-+            case NOT_YET_IMPLEMENTED_Pattern:
++            case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
                  y = 0
          self.assertIs(x, False)
          self.assertEqual(y, 0)
@@ -145,7 +145,7 @@ with match() as match:
          y = None
          match x:
 -            case 1e1000:
-+            case NOT_YET_IMPLEMENTED_Pattern:
++            case "NOT_YET_IMPLEMENTED_PatternMatchValue":
                  y = 0
          self.assertEqual(x, 0)
          self.assertIs(y, None)
@@ -153,7 +153,7 @@ with match() as match:
          x = range(3)
          match x:
 -            case [y, case as x, z]:
-+            case NOT_YET_IMPLEMENTED_Pattern:
++            case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
                  w = 0
  
      # At least one of the above branches must have been taken, because every Python
@@ -188,9 +188,9 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
         ]
 
     match match:
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
             match match:
-                case NOT_YET_IMPLEMENTED_Pattern:
+                case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
                     pass
 
     if all(version.is_python2() for version in target_versions):
@@ -210,7 +210,7 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
     def test_patma_139(self):
         x = False
         match x:
-            case NOT_YET_IMPLEMENTED_Pattern:
+            case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
                 y = 0
         self.assertIs(x, False)
         self.assertEqual(y, 0)
@@ -237,14 +237,14 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
         x = 0
         y = None
         match x:
-            case NOT_YET_IMPLEMENTED_Pattern:
+            case "NOT_YET_IMPLEMENTED_PatternMatchValue":
                 y = 0
         self.assertEqual(x, 0)
         self.assertIs(y, None)
 
         x = range(3)
         match x:
-            case NOT_YET_IMPLEMENTED_Pattern:
+            case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
                 w = 0
 
     # At least one of the above branches must have been taken, because every Python

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_310__pattern_matching_simple.py.snap

@@ -109,123 +109,123 @@ def where_is(point):
  
  match command.split():
 -    case [action, obj]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          ...  # interpret action, obj
  
  match command.split():
 -    case [action]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          ...  # interpret single-verb action
 -    case [action, obj]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          ...  # interpret action, obj
  
  match command.split():
 -    case ["quit"]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          print("Goodbye!")
          quit_game()
 -    case ["look"]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          current_room.describe()
 -    case ["get", obj]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          character.get(obj, current_room)
 -    case ["go", direction]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          current_room = current_room.neighbor(direction)
      # The rest of your commands go here
  
  match command.split():
 -    case ["drop", *objects]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          for obj in objects:
              character.drop(obj, current_room)
      # The rest of your commands go here
  
  match command.split():
 -    case ["quit"]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          pass
 -    case ["go", direction]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          print("Going:", direction)
 -    case ["drop", *objects]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          print("Dropping: ", *objects)
 -    case _:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          print(f"Sorry, I couldn't understand {command!r}")
  
  match command.split():
 -    case ["north"] | ["go", "north"]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          current_room = current_room.neighbor("north")
 -    case ["get", obj] | ["pick", "up", obj] | ["pick", obj, "up"]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          ...  # Code for picking up the given object
  
  match command.split():
 -    case ["go", ("north" | "south" | "east" | "west")]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          current_room = current_room.neighbor(...)
          # how do I know which direction to go?
  
  match command.split():
 -    case ["go", ("north" | "south" | "east" | "west") as direction]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          current_room = current_room.neighbor(direction)
  
  match command.split():
 -    case ["go", direction] if direction in current_room.exits:
-+    case NOT_YET_IMPLEMENTED_Pattern if direction in current_room.exits:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2] if direction in current_room.exits:
          current_room = current_room.neighbor(direction)
 -    case ["go", _]:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
          print("Sorry, you can't go that way")
  
  match event.get():
 -    case Click(position=(x, y)):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          handle_click_at(x, y)
 -    case KeyPress(key_name="Q") | Quit():
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
          game.quit()
 -    case KeyPress(key_name="up arrow"):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          game.go_north()
 -    case KeyPress():
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          pass  # Ignore other keystrokes
 -    case other_event:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          raise ValueError(f"Unrecognized event: {other_event}")
  
  match event.get():
 -    case Click((x, y), button=Button.LEFT):  # This is a left click
-+    case NOT_YET_IMPLEMENTED_Pattern:  # This is a left click
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):  # This is a left click
          handle_click_at(x, y)
 -    case Click():
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          pass  # ignore other clicks
  
  
  def where_is(point):
      match point:
 -        case Point(x=0, y=0):
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
              print("Origin")
 -        case Point(x=0, y=y):
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
              print(f"Y={y}")
 -        case Point(x=x, y=0):
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
              print(f"X={x}")
 -        case Point():
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
              print("Somewhere else")
 -        case _:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
              print("Not a point")
 ```
 
@@ -235,94 +235,94 @@ def where_is(point):
 # Cases sampled from PEP 636 examples
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         ...  # interpret action, obj
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         ...  # interpret single-verb action
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         ...  # interpret action, obj
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         print("Goodbye!")
         quit_game()
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         current_room.describe()
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         character.get(obj, current_room)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         current_room = current_room.neighbor(direction)
     # The rest of your commands go here
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         for obj in objects:
             character.drop(obj, current_room)
     # The rest of your commands go here
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         print("Going:", direction)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         print("Dropping: ", *objects)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         print(f"Sorry, I couldn't understand {command!r}")
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         current_room = current_room.neighbor("north")
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         ...  # Code for picking up the given object
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         current_room = current_room.neighbor(...)
         # how do I know which direction to go?
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         current_room = current_room.neighbor(direction)
 
 match command.split():
-    case NOT_YET_IMPLEMENTED_Pattern if direction in current_room.exits:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2] if direction in current_room.exits:
         current_room = current_room.neighbor(direction)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         print("Sorry, you can't go that way")
 
 match event.get():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         handle_click_at(x, y)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchOf | (y):
         game.quit()
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         game.go_north()
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         pass  # Ignore other keystrokes
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         raise ValueError(f"Unrecognized event: {other_event}")
 
 match event.get():
-    case NOT_YET_IMPLEMENTED_Pattern:  # This is a left click
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):  # This is a left click
         handle_click_at(x, y)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         pass  # ignore other clicks
 
 
 def where_is(point):
     match point:
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
             print("Origin")
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
             print(f"Y={y}")
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
             print(f"X={x}")
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
             print("Somewhere else")
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
             print("Not a point")
 ```
 

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_310__pattern_matching_style.py.snap

@@ -68,21 +68,21 @@ match match(
 @@ -1,35 +1,34 @@
  match something:
 -    case b():
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          print(1 + 1)
 -    case c(
 -        very_complex=True, perhaps_even_loooooooooooooooooooooooooooooooooooooong=-1
 -    ):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          print(1)
 -    case c(
 -        very_complex=True,
 -        perhaps_even_loooooooooooooooooooooooooooooooooooooong=-1,
 -    ):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          print(2)
 -    case a:
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
          pass
  
 -match(arg)  # comment
@@ -113,7 +113,7 @@ match match(
 -    case case(
 -        arg,  # comment
 -    ):
-+    case NOT_YET_IMPLEMENTED_Pattern:
++    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
          pass
 ```
 
@@ -121,13 +121,13 @@ match match(
 
 ```py
 match something:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         print(1 + 1)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         print(1)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         print(2)
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
 match(
@@ -152,7 +152,7 @@ re.match(
 )
 re.match()
 match match():
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case NOT_YET_IMPLEMENTED_PatternMatchClass(0, 0):
         pass
 ```
 

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_310__remove_newline_after_match.py.snap

@@ -35,19 +35,19 @@ def http_status(status):
  def http_status(status):
      match status:
 -        case 400:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
              return "Bad request"
  
 -        case 401:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
              return "Unauthorized"
  
 -        case 403:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
              return "Forbidden"
  
 -        case 404:
-+        case NOT_YET_IMPLEMENTED_Pattern:
++        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
              return "Not found"
 ```
 
@@ -56,16 +56,16 @@ def http_status(status):
 ```py
 def http_status(status):
     match status:
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
             return "Bad request"
 
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
             return "Unauthorized"
 
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
             return "Forbidden"
 
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
             return "Not found"
 ```
 

crates/ruff_python_formatter/tests/snapshots/format@parentheses__opening_parentheses_comment_empty.py.snap

@@ -139,10 +139,10 @@ with (  # d 1
     pass
 match (  # d 2
 ):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 match d3:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 while (  # d 4
 ):

crates/ruff_python_formatter/tests/snapshots/format@parentheses__opening_parentheses_comment_value.py.snap

@@ -219,10 +219,13 @@ with (  # d 1
 match (  # d 2
     x
 ):
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 match d3:
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case (
+        # d 3
+        x as NOT_YET_IMPLEMENTED_PatternMatchAs
+    ):
         pass
 while (  # d 4
     x

crates/ruff_python_formatter/tests/snapshots/format@statement__match.py.snap

@@ -114,13 +114,46 @@ match long_lines:
         bbbbbbbbaaaaaahhhh == 2
     ):  # another comment
         pass
+
+
+match pattern_comments:
+    case (
+    only_trailing  # trailing 1
+    # trailing 2
+# trailing 3
+    ):
+        pass
+
+
+match pattern_comments:
+    case (  # leading
+    only_leading
+    ):
+        pass
+
+
+match pattern_comments:
+    case (
+    # leading
+    leading_and_trailing  # trailing 1
+    # trailing 2
+# trailing 3
+    ):
+        pass
+
+
+match pattern_comments:
+    case (
+    no_comments
+    ):
+        pass
 ```
 
 ## Output
 ```py
 # leading match comment
 match foo:  # dangling match comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         pass
 
 
@@ -130,7 +163,7 @@ match (  # leading expr comment
     foo  # trailing expr comment
     # another trailing expr comment
 ):  # dangling match comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         pass
 
 
@@ -138,7 +171,7 @@ match (  # leading expr comment
 match (  # hello
     foo,  # trailing expr comment  # another
 ):  # dangling match comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         pass
 
 
@@ -147,13 +180,13 @@ match [  # comment
     second,
     third,
 ]:  # another comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
 match (  # comment
     "a b c"
 ).split():  # another comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
 
@@ -161,65 +194,97 @@ match (  # comment
     # let's go
     yield foo
 ):  # another comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2]:
         pass
 
 
 match aaaaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh:  # comment
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         pass
 
 
 def foo():
     match inside_func:  # comment
-        case NOT_YET_IMPLEMENTED_Pattern:
+        case "NOT_YET_IMPLEMENTED_PatternMatchValue":
             pass
 
 
 match newlines:
     # case 1 leading comment
 
-    case NOT_YET_IMPLEMENTED_Pattern:  # case dangling comment
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":  # case dangling comment
         # pass leading comment
         pass
         # pass trailing comment
 
     # case 2 leading comment
 
-    case NOT_YET_IMPLEMENTED_Pattern if foo == 2:  # second
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if foo == 2:  # second
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern if (foo := 1):  # third
+    case [NOT_YET_IMPLEMENTED_PatternMatchSequence, 2] if (foo := 1):  # third
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue":
         pass
-    case NOT_YET_IMPLEMENTED_Pattern:
+    case x as NOT_YET_IMPLEMENTED_PatternMatchAs:
         pass
 
 
 match long_lines:
-    case NOT_YET_IMPLEMENTED_Pattern if aaaaaaaaahhhhhhhh == 1 and bbbbbbaaaaaaaaaaa == 2:  # comment
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if aaaaaaaaahhhhhhhh == 1 and bbbbbbaaaaaaaaaaa == 2:  # comment
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern if (
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if (
         aaaaaaaaahhhhhhhh == 1 and bbbbbbaaaaaaaaaaa == 2
     ):  # comment
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern if foo := 1:
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if foo := 1:
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern if (foo := 1):
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if (foo := 1):
         pass
 
-    case NOT_YET_IMPLEMENTED_Pattern if (
+    case "NOT_YET_IMPLEMENTED_PatternMatchValue" if (
         aaaaaaahhhhhhhhhhh == 1 and bbbbbbbbaaaaaahhhh == 2
     ):  # another comment
         pass
+
+
+match pattern_comments:
+    case (
+        x as NOT_YET_IMPLEMENTED_PatternMatchAs  # trailing 1
+        # trailing 2
+        # trailing 3
+    ):
+        pass
+
+
+match pattern_comments:
+    case (
+        # leading
+        x as NOT_YET_IMPLEMENTED_PatternMatchAs
+    ):
+        pass
+
+
+match pattern_comments:
+    case (
+        # leading
+        x as NOT_YET_IMPLEMENTED_PatternMatchAs  # trailing 1
+        # trailing 2
+        # trailing 3
+    ):
+        pass
+
+
+match pattern_comments:
+    case (x as NOT_YET_IMPLEMENTED_PatternMatchAs):
+        pass
 ```