Wire up fixups for precedence

Author: dtolnay

Cargo.toml

@@ -19,13 +19,13 @@ verbatim = ["syn/parsing"]
 
 [dependencies]
 proc-macro2 = { version = "1.0.80", default-features = false }
-syn = { version = "2.0.81", default-features = false, features = ["full"] }
+syn = { version = "2.0.95", default-features = false, features = ["full"] }
 
 [dev-dependencies]
 indoc = "2"
 proc-macro2 = { version = "1.0.80", default-features = false }
 quote = { version = "1.0.35", default-features = false }
-syn = { version = "2.0.81", default-features = false, features = ["parsing"] }
+syn = { version = "2.0.95", default-features = false, features = ["parsing"] }
 
 [lib]
 doc-scrape-examples = false

src/attr.rs

@@ -1,4 +1,5 @@
 use crate::algorithm::Printer;
+use crate::fixup::FixupContext;
 use crate::path::PathKind;
 use crate::INDENT;
 use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
@@ -102,7 +103,7 @@ impl Printer {
     fn meta_name_value(&mut self, meta: &MetaNameValue) {
         self.path(&meta.path, PathKind::Simple);
         self.word(" = ");
-        self.expr(&meta.value);
+        self.expr(&meta.value, FixupContext::NONE);
     }
 
     fn attr_tokens(&mut self, tokens: TokenStream) {

src/classify.rs

@@ -10,51 +10,54 @@ pub(crate) fn requires_semi_to_be_stmt(expr: &Expr) -> bool {
     }
 }
 
-pub(crate) fn requires_comma_to_be_match_arm(expr: &Expr) -> bool {
-    match expr {
-        #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
-        Expr::If(_)
-        | Expr::Match(_)
-        | Expr::Block(_) | Expr::Unsafe(_) // both under ExprKind::Block in rustc
-        | Expr::While(_)
-        | Expr::Loop(_)
-        | Expr::ForLoop(_)
-        | Expr::TryBlock(_)
-        | Expr::Const(_) => false,
+pub(crate) fn requires_comma_to_be_match_arm(mut expr: &Expr) -> bool {
+    loop {
+        match expr {
+            #![cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
+            Expr::If(_)
+            | Expr::Match(_)
+            | Expr::Block(_) | Expr::Unsafe(_) // both under ExprKind::Block in rustc
+            | Expr::While(_)
+            | Expr::Loop(_)
+            | Expr::ForLoop(_)
+            | Expr::TryBlock(_)
+            | Expr::Const(_) => return false,
+
+            Expr::Array(_)
+            | Expr::Assign(_)
+            | Expr::Async(_)
+            | Expr::Await(_)
+            | Expr::Binary(_)
+            | Expr::Break(_)
+            | Expr::Call(_)
+            | Expr::Cast(_)
+            | Expr::Closure(_)
+            | Expr::Continue(_)
+            | Expr::Field(_)
+            | Expr::Index(_)
+            | Expr::Infer(_)
+            | Expr::Let(_)
+            | Expr::Lit(_)
+            | Expr::Macro(_)
+            | Expr::MethodCall(_)
+            | Expr::Paren(_)
+            | Expr::Path(_)
+            | Expr::Range(_)
+            | Expr::RawAddr(_)
+            | Expr::Reference(_)
+            | Expr::Repeat(_)
+            | Expr::Return(_)
+            | Expr::Struct(_)
+            | Expr::Try(_)
+            | Expr::Tuple(_)
+            | Expr::Unary(_)
+            | Expr::Yield(_)
+            | Expr::Verbatim(_) => return true,
 
-        Expr::Array(_)
-        | Expr::Assign(_)
-        | Expr::Async(_)
-        | Expr::Await(_)
-        | Expr::Binary(_)
-        | Expr::Break(_)
-        | Expr::Call(_)
-        | Expr::Cast(_)
-        | Expr::Closure(_)
-        | Expr::Continue(_)
-        | Expr::Field(_)
-        | Expr::Group(_)
-        | Expr::Index(_)
-        | Expr::Infer(_)
-        | Expr::Let(_)
-        | Expr::Lit(_)
-        | Expr::Macro(_)
-        | Expr::MethodCall(_)
-        | Expr::Paren(_)
-        | Expr::Path(_)
-        | Expr::Range(_)
-        | Expr::RawAddr(_)
-        | Expr::Reference(_)
-        | Expr::Repeat(_)
-        | Expr::Return(_)
-        | Expr::Struct(_)
-        | Expr::Try(_)
-        | Expr::Tuple(_)
-        | Expr::Unary(_)
-        | Expr::Yield(_)
-        | Expr::Verbatim(_) => true,
+            Expr::Group(group) => expr = &group.expr,
 
-        _ => true,
+            _ => return true,
+        }
     }
 }
 
@@ -150,7 +153,6 @@ pub(crate) fn expr_leading_label(mut expr: &Expr) -> bool {
             | Expr::Closure(_)
             | Expr::Const(_)
             | Expr::Continue(_)
-            | Expr::Group(_)
             | Expr::If(_)
             | Expr::Infer(_)
             | Expr::Let(_)
@@ -171,6 +173,13 @@ pub(crate) fn expr_leading_label(mut expr: &Expr) -> bool {
             | Expr::Verbatim(_)
             | Expr::Yield(_) => return false,
 
+            Expr::Group(e) => {
+                if !e.attrs.is_empty() {
+                    return false;
+                }
+                expr = &e.expr;
+            }
+
             _ => return false,
         }
     }
@@ -201,6 +210,7 @@ pub(crate) fn expr_trailing_brace(mut expr: &Expr) -> bool {
             },
             Expr::Cast(e) => return type_trailing_brace(&e.ty),
             Expr::Closure(e) => expr = &e.body,
+            Expr::Group(e) => expr = &e.expr,
             Expr::Let(e) => expr = &e.expr,
             Expr::Macro(e) => return matches!(e.mac.delimiter, MacroDelimiter::Brace(_)),
             Expr::Range(e) => match &e.end {
@@ -225,7 +235,6 @@ pub(crate) fn expr_trailing_brace(mut expr: &Expr) -> bool {
             | Expr::Call(_)
             | Expr::Continue(_)
             | Expr::Field(_)
-            | Expr::Group(_)
             | Expr::Index(_)
             | Expr::Infer(_)
             | Expr::Lit(_)

src/data.rs

@@ -1,4 +1,5 @@
 use crate::algorithm::Printer;
+use crate::fixup::FixupContext;
 use crate::iter::IterDelimited;
 use crate::path::PathKind;
 use crate::INDENT;
@@ -31,7 +32,7 @@ impl Printer {
         }
         if let Some((_eq_token, discriminant)) = &variant.discriminant {
             self.word(" = ");
-            self.expr(discriminant);
+            self.expr(discriminant, FixupContext::NONE);
         }
     }