Auto merge of #117928 - nnethercote:rustc_ast_pretty, r=fee1-dead

`rustc_ast_pretty` cleanups

Some improvements I found while looking at this code.

r? `@fee1-dead`

Author: bors

Cargo.lock

@@ -2060,9 +2060,9 @@ dependencies = [
 
 [[package]]
 name = "itertools"
-version = "0.10.5"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
 dependencies = [
  "either",
 ]
@@ -3471,6 +3471,7 @@ dependencies = [
 name = "rustc_ast_pretty"
 version = "0.0.0"
 dependencies = [
+ "itertools",
  "rustc_ast",
  "rustc_span",
  "thin-vec",

compiler/rustc_ast_passes/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-itertools = "0.10.1"
+itertools = "0.11"
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_attr = { path = "../rustc_attr" }

compiler/rustc_ast_pretty/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
+itertools = "0.11"
 rustc_ast = { path = "../rustc_ast" }
 rustc_span = { path = "../rustc_span" }
 thin-vec = "0.2.12"

compiler/rustc_ast_pretty/src/lib.rs

@@ -3,9 +3,7 @@
 #![doc(rust_logo)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
-#![feature(associated_type_bounds)]
 #![feature(box_patterns)]
-#![feature(with_negative_coherence)]
 #![recursion_limit = "256"]
 
 mod helpers;

compiler/rustc_ast_pretty/src/pp.rs

@@ -165,20 +165,20 @@ enum IndentStyle {
 }
 
 #[derive(Clone, Copy, Default, PartialEq)]
-pub struct BreakToken {
+pub(crate) struct BreakToken {
     offset: isize,
     blank_space: isize,
     pre_break: Option<char>,
 }
 
 #[derive(Clone, Copy, PartialEq)]
-pub struct BeginToken {
+pub(crate) struct BeginToken {
     indent: IndentStyle,
     breaks: Breaks,
 }
 
-#[derive(Clone, PartialEq)]
-pub enum Token {
+#[derive(PartialEq)]
+pub(crate) enum Token {
     // In practice a string token contains either a `&'static str` or a
     // `String`. `Cow` is overkill for this because we never modify the data,
     // but it's more convenient than rolling our own more specialized type.
@@ -229,7 +229,6 @@ pub struct Printer {
     last_printed: Option<Token>,
 }
 
-#[derive(Clone)]
 struct BufEntry {
     token: Token,
     size: isize,
@@ -251,16 +250,16 @@ impl Printer {
         }
     }
 
-    pub fn last_token(&self) -> Option<&Token> {
+    pub(crate) fn last_token(&self) -> Option<&Token> {
         self.last_token_still_buffered().or_else(|| self.last_printed.as_ref())
     }
 
-    pub fn last_token_still_buffered(&self) -> Option<&Token> {
+    pub(crate) fn last_token_still_buffered(&self) -> Option<&Token> {
         self.buf.last().map(|last| &last.token)
     }
 
     /// Be very careful with this!
-    pub fn replace_last_token_still_buffered(&mut self, token: Token) {
+    pub(crate) fn replace_last_token_still_buffered(&mut self, token: Token) {
         self.buf.last_mut().unwrap().token = token;
     }
 
@@ -314,7 +313,7 @@ impl Printer {
         }
     }
 
-    pub fn offset(&mut self, offset: isize) {
+    pub(crate) fn offset(&mut self, offset: isize) {
         if let Some(BufEntry { token: Token::Break(token), .. }) = &mut self.buf.last_mut() {
             token.offset += offset;
         }

compiler/rustc_ast_pretty/src/pp/convenience.rs

@@ -66,7 +66,7 @@ impl Printer {
         }
     }
 
-    pub fn hardbreak_tok_offset(off: isize) -> Token {
+    pub(crate) fn hardbreak_tok_offset(off: isize) -> Token {
         Token::Break(BreakToken {
             offset: off,
             blank_space: SIZE_INFINITY,