smol_str to a crate

5 files changed, 27 insertions, 92 deletions

diff --git a/crates/libsyntax2/src/ast/mod.rs b/crates/libsyntax2/src/ast/mod.rs
index 56bc099fe..e9362d048 100644
--- a/crates/libsyntax2/src/ast/mod.rs
+++ b/crates/libsyntax2/src/ast/mod.rs
@@ -1,6 +1,9 @@
 mod generated;
 
 use std::sync::Arc;
+
+use smol_str::SmolStr;
+
 use {
     SyntaxNode, SyntaxRoot, TreeRoot, SyntaxError,
     SyntaxKind::*,
@@ -64,7 +67,9 @@ impl<R: TreeRoot> Function<R> {
 }
 
 impl<R: TreeRoot> Name<R> {
-    pub fn text(&self) -> String {
-        self.syntax().text()
+    pub fn text(&self) -> SmolStr {
+        let ident = self.syntax().first_child()
+            .unwrap();
+        ident.leaf_text().unwrap()
     }
 }
diff --git a/crates/libsyntax2/src/lib.rs b/crates/libsyntax2/src/lib.rs
index ca33618a0..feef542c4 100644
--- a/crates/libsyntax2/src/lib.rs
+++ b/crates/libsyntax2/src/lib.rs
@@ -21,10 +21,11 @@
 //#![warn(unreachable_pub)] // rust-lang/rust#47816
 
 extern crate itertools;
-extern crate text_unit;
 extern crate unicode_xid;
 extern crate drop_bomb;
 extern crate parking_lot;
+extern crate smol_str;
+extern crate text_unit;
 
 pub mod algo;
 pub mod ast;
@@ -35,7 +36,6 @@ mod grammar;
 mod parser_impl;
 
 mod syntax_kinds;
-mod smol_str;
 mod yellow;
 /// Utilities for simple uses of the parser.
 pub mod utils;
diff --git a/crates/libsyntax2/src/smol_str.rs b/crates/libsyntax2/src/smol_str.rs
deleted file mode 100644
index abf69dce7..000000000
--- a/crates/libsyntax2/src/smol_str.rs
+++ /dev/null
@@ -1,83 +0,0 @@
-use std::{sync::Arc};
-
-const INLINE_CAP: usize = 22;
-const WS_TAG: u8 = (INLINE_CAP + 1) as u8;
-
-#[derive(Clone, Debug)]
-pub(crate) enum SmolStr {
-    Heap(Arc<str>),
-    Inline {
-        len: u8,
-        buf: [u8; INLINE_CAP],
-    },
-}
-
-impl SmolStr {
-    pub fn new(text: &str) -> SmolStr {
-        let len = text.len();
-        if len <= INLINE_CAP {
-            let mut buf = [0; INLINE_CAP];
-            buf[..len].copy_from_slice(text.as_bytes());
-            return SmolStr::Inline { len: len as u8, buf };
-        }
-
-        let newlines = text.bytes().take_while(|&b| b == b'\n').count();
-        let spaces = text[newlines..].bytes().take_while(|&b| b == b' ').count();
-        if newlines + spaces == len && newlines <= N_NEWLINES && spaces <= N_SPACES {
-            let mut buf = [0; INLINE_CAP];
-            buf[0] = newlines as u8;
-            buf[1] = spaces as u8;
-            return SmolStr::Inline { len: WS_TAG, buf };
-        }
-
-        SmolStr::Heap(
-            text.to_string().into_boxed_str().into()
-        )
-    }
-
-    pub fn as_str(&self) -> &str {
-        match self {
-            SmolStr::Heap(data) => &*data,
-            SmolStr::Inline { len, buf } => {
-                if *len == WS_TAG {
-                    let newlines = buf[0] as usize;
-                    let spaces = buf[1] as usize;
-                    assert!(newlines <= N_NEWLINES && spaces <= N_SPACES);
-                    return &WS[N_NEWLINES - newlines..N_NEWLINES + spaces]
-                }
-
-                let len = *len as usize;
-                let buf = &buf[..len];
-                unsafe { ::std::str::from_utf8_unchecked(buf) }
-            }
-        }
-    }
-}
-
-const N_NEWLINES: usize = 32;
-const N_SPACES: usize = 128;
-const WS: &str =
-    "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n                                                                                                                                ";
-
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    #[cfg(target_pointer_width = "64")]
-    fn smol_str_is_smol() {
-        assert_eq!(::std::mem::size_of::<SmolStr>(), 8 + 8 + 8)
-    }
-
-    #[test]
-    fn test_round_trip() {
-        let mut text = String::new();
-        for n in 0..256 {
-            let smol = SmolStr::new(&text);
-            assert_eq!(smol.as_str(), text.as_str());
-            text.push_str(&n.to_string());
-        }
-    }
-}
-
diff --git a/crates/libsyntax2/src/yellow/green.rs b/crates/libsyntax2/src/yellow/green.rs
index f505b26d7..700f2704f 100644
--- a/crates/libsyntax2/src/yellow/green.rs
+++ b/crates/libsyntax2/src/yellow/green.rs
@@ -1,8 +1,8 @@
 use std::sync::Arc;
-use {
-    SyntaxKind, TextUnit,
-    smol_str::SmolStr,
-};
+
+use smol_str::SmolStr;
+
+use {SyntaxKind, TextUnit};
 
 #[derive(Clone, Debug)]
 pub(crate) enum GreenNode {
@@ -31,7 +31,7 @@ impl GreenNode {
 
     pub fn text_len(&self) -> TextUnit {
         match self {
-            GreenNode::Leaf { text, ..} => TextUnit::of_str(text.as_str()),
+            GreenNode::Leaf { text, .. } => TextUnit::of_str(text.as_str()),
             GreenNode::Branch(b) => b.text_len(),
         }
     }
@@ -54,6 +54,13 @@ impl GreenNode {
             }
         }
     }
+
+    pub fn leaf_text(&self) -> Option<SmolStr> {
+        match self {
+            GreenNode::Leaf { text, .. } => Some(text.clone()),
+            GreenNode::Branch(_) => None,
+        }
+    }
 }
 
 #[derive(Clone, Debug)]
diff --git a/crates/libsyntax2/src/yellow/syntax.rs b/crates/libsyntax2/src/yellow/syntax.rs
index 00f76e51c..b264e008a 100644
--- a/crates/libsyntax2/src/yellow/syntax.rs
+++ b/crates/libsyntax2/src/yellow/syntax.rs
@@ -1,5 +1,7 @@
 use std::{fmt, sync::Arc};
 
+use smol_str::SmolStr;
+
 use {
     yellow::{RedNode, TreeRoot, SyntaxRoot, RedPtr},
     SyntaxKind::{self, *},
@@ -116,6 +118,10 @@ impl<R: TreeRoot> SyntaxNode<R> {
         self.first_child().is_none()
     }
 
+    pub fn leaf_text(&self) -> Option<SmolStr> {
+        self.red().green().leaf_text()
+    }
+
     fn red(&self) -> &RedNode {
         unsafe { self.red.get(&self.root) }
     }