Move pp::Printer helpers to direct impl

Author: Mark-Simulacrum

Diff for: src/librustc/hir/map/mod.rs

@@ -1212,8 +1212,6 @@ impl<'a> print::State<'a> {
             Node::Pat(a)          => self.print_pat(&a),
             Node::Arm(a)          => self.print_arm(&a),
             Node::Block(a)        => {
-                use syntax::print::pprust::PrintState;
-
                 // containing cbox, will be closed by print-block at }
                 self.cbox(print::indent_unit);
                 // head-ibox, will be closed by print-block after {

Diff for: src/librustc/hir/print.rs

@@ -73,6 +73,19 @@ pub struct State<'a> {
     ann: &'a (dyn PpAnn + 'a),
 }
 
+impl std::ops::Deref for State<'_> {
+    type Target = pp::Printer;
+    fn deref(&self) -> &Self::Target {
+        &self.s
+    }
+}
+
+impl std::ops::DerefMut for State<'_> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.s
+    }
+}
+
 impl<'a> PrintState<'a> for State<'a> {
     fn writer(&mut self) -> &mut pp::Printer {
         &mut self.s

Diff for: src/librustc_borrowck/dataflow.rs

@@ -8,7 +8,6 @@ use rustc::cfg::CFGIndex;
 use rustc::ty::TyCtxt;
 use std::mem;
 use std::usize;
-use syntax::print::pprust::PrintState;
 use log::debug;
 
 use rustc_data_structures::graph::implementation::OUTGOING;

Diff for: src/librustc_driver/pretty.rs

@@ -19,7 +19,6 @@ use rustc_mir::util::{write_mir_pretty, write_mir_graphviz};
 use syntax::ast;
 use syntax::mut_visit::MutVisitor;
 use syntax::print::{pprust};
-use syntax::print::pprust::PrintState;
 use syntax_pos::FileName;
 
 use graphviz as dot;

Diff for: src/libsyntax/lib.rs

@@ -162,6 +162,7 @@ pub mod visit;
 pub mod print {
     pub mod pp;
     pub mod pprust;
+    mod helpers;
 }
 
 pub mod ext {

Diff for: src/libsyntax/parse/diagnostics.rs

@@ -611,8 +611,6 @@ impl<'a> Parser<'a> {
         match ty.node {
             TyKind::Rptr(ref lifetime, ref mut_ty) => {
                 let sum_with_parens = pprust::to_string(|s| {
-                    use crate::print::pprust::PrintState;
-
                     s.s.word("&");
                     s.print_opt_lifetime(lifetime);
                     s.print_mutability(mut_ty.mutbl);

Diff for: src/libsyntax/parse/parser.rs

@@ -2571,7 +2571,6 @@ impl<'a> Parser<'a> {
                               None => continue,
                           };
                           let sugg = pprust::to_string(|s| {
-                              use crate::print::pprust::PrintState;
                               s.popen();
                               s.print_expr(&e);
                               s.s.word( ".");
@@ -4588,7 +4587,7 @@ impl<'a> Parser<'a> {
                         stmt_span = stmt_span.with_hi(self.prev_span.hi());
                     }
                     let sugg = pprust::to_string(|s| {
-                        use crate::print::pprust::{PrintState, INDENT_UNIT};
+                        use crate::print::pprust::INDENT_UNIT;
                         s.ibox(INDENT_UNIT);
                         s.bopen();
                         s.print_stmt(&stmt);

Diff for: src/libsyntax/print/helpers.rs

@@ -0,0 +1,34 @@
+use std::borrow::Cow;
+use crate::print::pp::Printer;
+
+impl Printer {
+    pub fn word_space<W: Into<Cow<'static, str>>>(&mut self, w: W) {
+        self.word(w);
+        self.space();
+    }
+
+    pub fn popen(&mut self) {
+        self.word("(");
+    }
+
+    pub fn pclose(&mut self) {
+        self.word(")");
+    }
+
+    pub fn hardbreak_if_not_bol(&mut self) {
+        if !self.is_beginning_of_line() {
+            self.hardbreak()
+        }
+    }
+
+    pub fn space_if_not_bol(&mut self) {
+        if !self.is_beginning_of_line() { self.space(); }
+    }
+
+    pub fn nbsp(&mut self) { self.word(" ") }
+
+    pub fn word_nbsp<S: Into<Cow<'static, str>>>(&mut self, w: S) {
+        self.word(w);
+        self.nbsp()
+    }
+}

Diff for: src/libsyntax/print/pp.rs

@@ -597,15 +597,15 @@ impl Printer {
     // Convenience functions to talk to the printer.
 
     /// "raw box"
-    crate fn rbox(&mut self, indent: usize, b: Breaks) {
+    pub fn rbox(&mut self, indent: usize, b: Breaks) {
         self.scan_begin(BeginToken {
             offset: indent as isize,
             breaks: b
         })
     }
 
     /// Inconsistent breaking box
-    crate fn ibox(&mut self, indent: usize) {
+    pub fn ibox(&mut self, indent: usize) {
         self.rbox(indent, Breaks::Inconsistent)
     }
 
@@ -621,7 +621,7 @@ impl Printer {
         })
     }
 
-    crate fn end(&mut self) {
+    pub fn end(&mut self) {
         self.scan_end()
     }
 

Diff for: src/libsyntax/print/pprust.rs

@@ -432,37 +432,22 @@ fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String {
     format!("{}{}", to_string(|s| s.print_visibility(vis)), s)
 }
 
-pub trait PrintState<'a> {
-    fn writer(&mut self) -> &mut pp::Printer;
-    fn comments(&mut self) -> &mut Option<Comments<'a>>;
-
-    fn word_space<S: Into<Cow<'static, str>>>(&mut self, w: S) {
-        self.writer().word(w);
-        self.writer().space()
-    }
-
-    fn popen(&mut self) { self.writer().word("(") }
-
-    fn pclose(&mut self) { self.writer().word(")") }
-
-    fn hardbreak_if_not_bol(&mut self) {
-        if !self.writer().is_beginning_of_line() {
-            self.writer().hardbreak()
-        }
-    }
-
-    // "raw box"
-    fn rbox(&mut self, u: usize, b: pp::Breaks) {
-        self.writer().rbox(u, b)
+impl std::ops::Deref for State<'_> {
+    type Target = pp::Printer;
+    fn deref(&self) -> &Self::Target {
+        &self.s
     }
+}
 
-    fn ibox(&mut self, u: usize) {
-        self.writer().ibox(u);
+impl std::ops::DerefMut for State<'_> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.s
     }
+}
 
-    fn end(&mut self) {
-        self.writer().end()
-    }
+pub trait PrintState<'a>: std::ops::Deref<Target=pp::Printer> + std::ops::DerefMut {
+    fn writer(&mut self) -> &mut pp::Printer;
+    fn comments(&mut self) -> &mut Option<Comments<'a>>;
 
     fn commasep<T, F>(&mut self, b: Breaks, elts: &[T], mut op: F)
         where F: FnMut(&mut Self, &T),
@@ -728,12 +713,6 @@ pub trait PrintState<'a> {
         }
         self.end();
     }
-
-    fn space_if_not_bol(&mut self) {
-        if !self.writer().is_beginning_of_line() { self.writer().space(); }
-    }
-
-    fn nbsp(&mut self) { self.writer().word(" ") }
 }
 
 impl<'a> PrintState<'a> for State<'a> {
@@ -747,15 +726,6 @@ impl<'a> PrintState<'a> for State<'a> {
 }
 
 impl<'a> State<'a> {
-    pub fn cbox(&mut self, u: usize) {
-        self.s.cbox(u);
-    }
-
-    crate fn word_nbsp<S: Into<Cow<'static, str>>>(&mut self, w: S) {
-        self.s.word(w);
-        self.nbsp()
-    }
-
     crate fn head<S: Into<Cow<'static, str>>>(&mut self, w: S) {
         let w = w.into();
         // outer-box is consistent