Move unparse utility methods onto Generator (#4497)

crates/ruff_python_ast/src/source_code/generator.rs

@@ -101,8 +101,22 @@ impl<'a> Generator<'a> {
         }
     }
 
-    pub fn generate(self) -> String {
-        self.buffer
+    /// Generate source code from a [`Stmt`].
+    pub fn stmt(mut self, stmt: &Stmt) -> String {
+        self.unparse_stmt(stmt);
+        self.generate()
+    }
+
+    /// Generate source code from an [`Expr`].
+    pub fn expr(mut self, expr: &Expr) -> String {
+        self.unparse_expr(expr, 0);
+        self.generate()
+    }
+
+    /// Generate source code from a [`Constant`].
+    pub fn constant(mut self, constant: &Constant) -> String {
+        self.unparse_constant(constant);
+        self.generate()
     }
 
     fn newline(&mut self) {
@@ -165,13 +179,17 @@ impl<'a> Generator<'a> {
         self.p_if(!std::mem::take(first), s);
     }
 
-    pub fn unparse_suite<U>(&mut self, suite: &Suite<U>) {
+    pub(crate) fn generate(self) -> String {
+        self.buffer
+    }
+
+    pub(crate) fn unparse_suite<U>(&mut self, suite: &Suite<U>) {
         for stmt in suite {
             self.unparse_stmt(stmt);
         }
     }
 
-    pub fn unparse_stmt<U>(&mut self, ast: &Stmt<U>) {
+    pub(crate) fn unparse_stmt<U>(&mut self, ast: &Stmt<U>) {
         macro_rules! statement {
             ($body:block) => {{
                 self.newline();
@@ -824,7 +842,7 @@ impl<'a> Generator<'a> {
         self.body(&ast.body);
     }
 
-    pub fn unparse_expr<U>(&mut self, ast: &Expr<U>, level: u8) {
+    pub(crate) fn unparse_expr<U>(&mut self, ast: &Expr<U>, level: u8) {
         macro_rules! opprec {
             ($opty:ident, $x:expr, $enu:path, $($var:ident($op:literal, $prec:ident)),*$(,)?) => {
                 match $x {
@@ -1218,7 +1236,7 @@ impl<'a> Generator<'a> {
         }
     }
 
-    pub fn unparse_constant(&mut self, constant: &Constant) {
+    pub(crate) fn unparse_constant(&mut self, constant: &Constant) {
         assert_eq!(f64::MAX_10_EXP, 308);
         let inf_str = "1e309";
         match constant {