From ad80a0c551458de7d27a98d182d7f559de04f291 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Thu, 31 Jan 2019 18:51:17 +0300
Subject: preserve token spacing

---
 crates/ra_macros/Cargo.toml        |  1 -
 crates/ra_macros/src/mbe.rs        |  2 +-
 crates/ra_macros/src/mbe_parser.rs |  8 +++-----
 crates/ra_macros/src/tt.rs         | 31 +++++++++++++++++++++++++------
 crates/ra_macros/src/tt_cursor.rs  |  2 +-
 5 files changed, 30 insertions(+), 14 deletions(-)

(limited to 'crates/ra_macros')

diff --git a/crates/ra_macros/Cargo.toml b/crates/ra_macros/Cargo.toml
index 1c9cc9e92..7d3cb055c 100644
--- a/crates/ra_macros/Cargo.toml
+++ b/crates/ra_macros/Cargo.toml
@@ -7,4 +7,3 @@ authors = ["Aleksey Kladov <aleksey.kladov@gmail.com>"]
 [dependencies]
 rustc-hash = "1.0.0"
 smol_str = "0.1.9"
-join_to_string = "0.1.3"
diff --git a/crates/ra_macros/src/mbe.rs b/crates/ra_macros/src/mbe.rs
index ac76d64e4..d4106a41c 100644
--- a/crates/ra_macros/src/mbe.rs
+++ b/crates/ra_macros/src/mbe.rs
@@ -45,7 +45,7 @@ pub(crate) struct Subtree {
 pub(crate) struct Repeat {
     pub(crate) subtree: Subtree,
     pub(crate) kind: RepeatKind,
-    pub(crate) separator: Option<Punct>,
+    pub(crate) separator: Option<char>,
 }
 
 #[derive(Debug)]
diff --git a/crates/ra_macros/src/mbe_parser.rs b/crates/ra_macros/src/mbe_parser.rs
index 279ab2f25..483594590 100644
--- a/crates/ra_macros/src/mbe_parser.rs
+++ b/crates/ra_macros/src/mbe_parser.rs
@@ -28,16 +28,14 @@ fn parse_subtree(tt: &tt::Subtree) -> Option<mbe::Subtree> {
     while let Some(tt) = p.eat() {
         let child: mbe::TokenTree = match tt {
             tt::TokenTree::Leaf(leaf) => match leaf {
-                tt::Leaf::Punct(tt::Punct { char: '$' }) => {
+                tt::Leaf::Punct(tt::Punct { char: '$', .. }) => {
                     if p.at_ident().is_some() {
                         mbe::Leaf::from(parse_var(&mut p)?).into()
                     } else {
                         parse_repeat(&mut p)?.into()
                     }
                 }
-                tt::Leaf::Punct(tt::Punct { char }) => {
-                    mbe::Leaf::from(mbe::Punct { char: *char }).into()
-                }
+                tt::Leaf::Punct(punct) => mbe::Leaf::from(*punct).into(),
                 tt::Leaf::Ident(tt::Ident { text }) => {
                     mbe::Leaf::from(mbe::Ident { text: text.clone() }).into()
                 }
@@ -78,7 +76,7 @@ fn parse_repeat(p: &mut TtCursor) -> Option<mbe::Repeat> {
     let sep = p.eat_punct()?;
     let (separator, rep) = match sep.char {
         '*' | '+' | '?' => (None, sep.char),
-        char => (Some(mbe::Punct { char }), p.eat_punct()?.char),
+        char => (Some(char), p.eat_punct()?.char),
     };
 
     let kind = match rep {
diff --git a/crates/ra_macros/src/tt.rs b/crates/ra_macros/src/tt.rs
index 56e930f00..2855bae51 100644
--- a/crates/ra_macros/src/tt.rs
+++ b/crates/ra_macros/src/tt.rs
@@ -1,7 +1,6 @@
 use std::fmt;
 
 use smol_str::SmolStr;
-use join_to_string::join;
 
 #[derive(Debug, Clone)]
 pub enum TokenTree {
@@ -37,9 +36,16 @@ pub struct Literal {
     pub text: SmolStr,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Punct {
     pub char: char,
+    pub spacing: Spacing,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Spacing {
+    Alone,
+    Joint,
 }
 
 #[derive(Debug, Clone)]
@@ -64,10 +70,23 @@ impl fmt::Display for Subtree {
             Delimiter::Bracket => ("[", "]"),
             Delimiter::None => ("", ""),
         };
-        join(self.token_trees.iter())
-            .separator(" ")
-            .surround_with(l, r)
-            .to_fmt(f)
+        f.write_str(l)?;
+        let mut needs_space = false;
+        for tt in self.token_trees.iter() {
+            if needs_space {
+                f.write_str(" ")?;
+            }
+            needs_space = true;
+            match tt {
+                TokenTree::Leaf(Leaf::Punct(p)) => {
+                    needs_space = p.spacing == Spacing::Alone;
+                    fmt::Display::fmt(p, f)?
+                }
+                tt => fmt::Display::fmt(tt, f)?,
+            }
+        }
+        f.write_str(r)?;
+        Ok(())
     }
 }
 
diff --git a/crates/ra_macros/src/tt_cursor.rs b/crates/ra_macros/src/tt_cursor.rs
index 6dc9f400d..046770a0f 100644
--- a/crates/ra_macros/src/tt_cursor.rs
+++ b/crates/ra_macros/src/tt_cursor.rs
@@ -28,7 +28,7 @@ impl<'a> TtCursor<'a> {
 
     pub(crate) fn at_char(&self, char: char) -> bool {
         match self.at_punct() {
-            Some(tt::Punct { char: c }) if *c == char => true,
+            Some(tt::Punct { char: c, .. }) if *c == char => true,
             _ => false,
         }
     }
-- 
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