Create dedicated Body nodes in the formatter CST (#3223)

crates/ruff_python_formatter/src/format/builders.rs

@@ -4,17 +4,55 @@ use ruff_text_size::{TextRange, TextSize};
 
 use crate::context::ASTFormatContext;
 use crate::core::types::Range;
-use crate::cst::Stmt;
+use crate::cst::{Body, Stmt};
 use crate::shared_traits::AsFormat;
+use crate::trivia::{Relationship, TriviaKind};
 
 #[derive(Copy, Clone)]
 pub struct Block<'a> {
-    body: &'a [Stmt],
+    body: &'a Body,
 }
 
 impl Format<ASTFormatContext<'_>> for Block<'_> {
     fn fmt(&self, f: &mut Formatter<ASTFormatContext<'_>>) -> FormatResult<()> {
-        for (i, stmt) in self.body.iter().enumerate() {
+        for (i, stmt) in self.body.node.iter().enumerate() {
+            if i > 0 {
+                write!(f, [hard_line_break()])?;
+            }
+            write!(f, [stmt.format()])?;
+        }
+
+        for trivia in &self.body.trivia {
+            if matches!(trivia.relationship, Relationship::Dangling) {
+                match trivia.kind {
+                    TriviaKind::EmptyLine => {
+                        write!(f, [empty_line()])?;
+                    }
+                    TriviaKind::OwnLineComment(range) => {
+                        write!(f, [literal(range), hard_line_break()])?;
+                    }
+                    _ => {}
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+#[inline]
+pub fn block(body: &Body) -> Block {
+    Block { body }
+}
+
+#[derive(Copy, Clone)]
+pub struct Statements<'a> {
+    suite: &'a [Stmt],
+}
+
+impl Format<ASTFormatContext<'_>> for Statements<'_> {
+    fn fmt(&self, f: &mut Formatter<ASTFormatContext<'_>>) -> FormatResult<()> {
+        for (i, stmt) in self.suite.iter().enumerate() {
             if i > 0 {
                 write!(f, [hard_line_break()])?;
             }
@@ -24,9 +62,8 @@ impl Format<ASTFormatContext<'_>> for Block<'_> {
     }
 }
 
-#[inline]
-pub fn block(body: &[Stmt]) -> Block {
-    Block { body }
+pub fn statements(suite: &[Stmt]) -> Statements {
+    Statements { suite }
 }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]