Remove Interner<T> and rename StrInterner to Interner.

Author: jseyfried

src/librustc_metadata/decoder.rs

@@ -450,7 +450,7 @@ pub fn get_adt_def<'a, 'tcx>(intr: &IdentInterner,
                                   struct_field_family_to_visibility(ff))
         }).chain(reader::tagged_docs(doc, tag_item_unnamed_field).map(|f| {
             let ff = item_family(f);
-            let name = intr.intern(&index.to_string());
+            let name = intr.intern(index.to_string());
             index += 1;
             ty::FieldDefData::new(item_def_id(f, cdata), name,
                                   struct_field_family_to_visibility(ff))
@@ -1187,7 +1187,7 @@ pub fn get_struct_field_names(intr: &IdentInterner, cdata: Cmd, id: DefIndex)
     reader::tagged_docs(item, tag_item_field).map(|an_item| {
         item_name(intr, an_item)
     }).chain(reader::tagged_docs(item, tag_item_unnamed_field).map(|_| {
-        let name = intr.intern(&index.to_string());
+        let name = intr.intern(index.to_string());
         index += 1;
         name
     })).collect()

src/librustc_trans/debuginfo/metadata.rs

@@ -81,7 +81,7 @@ pub struct UniqueTypeId(ast::Name);
 // UniqueTypeIds.
 pub struct TypeMap<'tcx> {
     // The UniqueTypeIds created so far
-    unique_id_interner: Interner<Rc<String>>,
+    unique_id_interner: Interner,
     // A map from UniqueTypeId to debuginfo metadata for that type. This is a 1:1 mapping.
     unique_id_to_metadata: FnvHashMap<UniqueTypeId, DIType>,
     // A map from types to debuginfo metadata. This is a N:1 mapping.
@@ -313,7 +313,7 @@ impl<'tcx> TypeMap<'tcx> {
         // Trim to size before storing permanently
         unique_type_id.shrink_to_fit();
 
-        let key = self.unique_id_interner.intern(Rc::new(unique_type_id));
+        let key = self.unique_id_interner.intern(unique_type_id);
         self.type_to_unique_id.insert(type_, UniqueTypeId(key));
 
         return UniqueTypeId(key);
@@ -383,7 +383,7 @@ impl<'tcx> TypeMap<'tcx> {
         let enum_variant_type_id = format!("{}::{}",
                                            &self.get_unique_type_id_as_string(enum_type_id),
                                            variant_name);
-        let interner_key = self.unique_id_interner.intern(Rc::new(enum_variant_type_id));
+        let interner_key = self.unique_id_interner.intern(enum_variant_type_id);
         UniqueTypeId(interner_key)
     }
 }

src/libsyntax/parse/token.rs

@@ -17,7 +17,7 @@ pub use self::Token::*;
 use ast::{self, BinOpKind};
 use ext::mtwt;
 use ptr::P;
-use util::interner::StrInterner;
+use util::interner::Interner;
 use tokenstream;
 
 use serialize::{Decodable, Decoder, Encodable, Encoder};
@@ -396,7 +396,7 @@ macro_rules! declare_keywords {(
     }
 
     fn mk_fresh_ident_interner() -> IdentInterner {
-        StrInterner::prefill(&[$($string,)*])
+        Interner::prefill(&[$($string,)*])
     }
 }}
 
@@ -472,7 +472,7 @@ declare_keywords! {
 }
 
 // looks like we can get rid of this completely...
-pub type IdentInterner = StrInterner;
+pub type IdentInterner = Interner;
 
 // if an interner exists in TLS, return it. Otherwise, prepare a
 // fresh one.

src/libsyntax/util/interner.rs

@@ -17,122 +17,45 @@ use ast::Name;
 use std::borrow::Borrow;
 use std::cell::RefCell;
 use std::collections::HashMap;
-use std::hash::Hash;
 use std::rc::Rc;
 
-pub struct Interner<T> {
-    map: RefCell<HashMap<T, Name>>,
-    vect: RefCell<Vec<T> >,
-}
-
-// when traits can extend traits, we should extend index<Name,T> to get []
-impl<T: Eq + Hash + Clone + 'static> Interner<T> {
-    pub fn new() -> Interner<T> {
-        Interner {
-            map: RefCell::new(HashMap::new()),
-            vect: RefCell::new(Vec::new()),
-        }
-    }
-
-    pub fn prefill(init: &[T]) -> Interner<T> {
-        let rv = Interner::new();
-        for v in init {
-            rv.intern((*v).clone());
-        }
-        rv
-    }
-
-    pub fn intern(&self, val: T) -> Name {
-        let mut map = self.map.borrow_mut();
-        if let Some(&idx) = (*map).get(&val) {
-            return idx;
-        }
-
-        let mut vect = self.vect.borrow_mut();
-        let new_idx = Name((*vect).len() as u32);
-        (*map).insert(val.clone(), new_idx);
-        (*vect).push(val);
-        new_idx
-    }
-
-    pub fn gensym(&self, val: T) -> Name {
-        let mut vect = self.vect.borrow_mut();
-        let new_idx = Name((*vect).len() as u32);
-        // leave out of .map to avoid colliding
-        (*vect).push(val);
-        new_idx
-    }
-
-    pub fn get(&self, idx: Name) -> T {
-        let vect = self.vect.borrow();
-        (*vect)[idx.0 as usize].clone()
-    }
-
-    pub fn len(&self) -> usize {
-        let vect = self.vect.borrow();
-        (*vect).len()
-    }
-
-    pub fn find<Q: ?Sized>(&self, val: &Q) -> Option<Name>
-    where T: Borrow<Q>, Q: Eq + Hash {
-        let map = self.map.borrow();
-        match (*map).get(val) {
-            Some(v) => Some(*v),
-            None => None,
-        }
-    }
-
-    pub fn clear(&self) {
-        *self.map.borrow_mut() = HashMap::new();
-        *self.vect.borrow_mut() = Vec::new();
-    }
-}
-
-#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(PartialEq, Eq, Hash)]
 struct RcStr(Rc<String>);
 
-impl RcStr {
-    fn new(string: &str) -> Self {
-        RcStr(Rc::new(string.to_owned()))
-    }
-}
-
 impl Borrow<str> for RcStr {
     fn borrow(&self) -> &str {
         &self.0
     }
 }
 
-/// A StrInterner differs from Interner<String> in that it accepts
-/// &str rather than RcStr, resulting in less allocation.
-pub struct StrInterner {
+pub struct Interner {
     map: RefCell<HashMap<RcStr, Name>>,
     vect: RefCell<Vec<Rc<String>> >,
 }
 
 /// When traits can extend traits, we should extend index<Name,T> to get []
-impl StrInterner {
-    pub fn new() -> StrInterner {
-        StrInterner {
+impl Interner {
+    pub fn new() -> Self {
+        Interner {
             map: RefCell::new(HashMap::new()),
             vect: RefCell::new(Vec::new()),
         }
     }
 
-    pub fn prefill(init: &[&str]) -> StrInterner {
-        let rv = StrInterner::new();
+    pub fn prefill(init: &[&str]) -> Self {
+        let rv = Interner::new();
         for &v in init { rv.intern(v); }
         rv
     }
 
-    pub fn intern(&self, val: &str) -> Name {
+    pub fn intern<T: Borrow<str> + Into<String>>(&self, val: T) -> Name {
         let mut map = self.map.borrow_mut();
-        if let Some(&idx) = map.get(val) {
+        if let Some(&idx) = map.get(val.borrow()) {
             return idx;
         }
 
         let new_idx = Name(self.len() as u32);
-        let val = Rc::new(val.to_owned());
+        let val = Rc::new(val.into());
         map.insert(RcStr(val.clone()), new_idx);
         self.vect.borrow_mut().push(val);
         new_idx
@@ -181,7 +104,7 @@ impl StrInterner {
         *self.vect.borrow_mut() = Vec::new();
     }
 
-    pub fn reset(&self, other: StrInterner) {
+    pub fn reset(&self, other: Interner) {
         *self.map.borrow_mut() = other.map.into_inner();
         *self.vect.borrow_mut() = other.vect.into_inner();
     }
@@ -190,57 +113,11 @@ impl StrInterner {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use super::RcStr;
     use ast::Name;
 
     #[test]
-    #[should_panic]
-    fn i1 () {
-        let i : Interner<RcStr> = Interner::new();
-        i.get(Name(13));
-    }
-
-    #[test]
-    fn interner_tests () {
-        let i : Interner<RcStr> = Interner::new();
-        // first one is zero:
-        assert_eq!(i.intern(RcStr::new("dog")), Name(0));
-        // re-use gets the same entry:
-        assert_eq!(i.intern(RcStr::new("dog")), Name(0));
-        // different string gets a different #:
-        assert_eq!(i.intern(RcStr::new("cat")), Name(1));
-        assert_eq!(i.intern(RcStr::new("cat")), Name(1));
-        // dog is still at zero
-        assert_eq!(i.intern(RcStr::new("dog")), Name(0));
-        // gensym gets 3
-        assert_eq!(i.gensym(RcStr::new("zebra") ), Name(2));
-        // gensym of same string gets new number :
-        assert_eq!(i.gensym (RcStr::new("zebra") ), Name(3));
-        // gensym of *existing* string gets new number:
-        assert_eq!(i.gensym(RcStr::new("dog")), Name(4));
-        assert_eq!(i.get(Name(0)), RcStr::new("dog"));
-        assert_eq!(i.get(Name(1)), RcStr::new("cat"));
-        assert_eq!(i.get(Name(2)), RcStr::new("zebra"));
-        assert_eq!(i.get(Name(3)), RcStr::new("zebra"));
-        assert_eq!(i.get(Name(4)), RcStr::new("dog"));
-    }
-
-    #[test]
-    fn i3 () {
-        let i : Interner<RcStr> = Interner::prefill(&[
-            RcStr::new("Alan"),
-            RcStr::new("Bob"),
-            RcStr::new("Carol")
-        ]);
-        assert_eq!(i.get(Name(0)), RcStr::new("Alan"));
-        assert_eq!(i.get(Name(1)), RcStr::new("Bob"));
-        assert_eq!(i.get(Name(2)), RcStr::new("Carol"));
-        assert_eq!(i.intern(RcStr::new("Bob")), Name(1));
-    }
-
-    #[test]
-    fn string_interner_tests() {
-        let i : StrInterner = StrInterner::new();
+    fn interner_tests() {
+        let i : Interner = Interner::new();
         // first one is zero:
         assert_eq!(i.intern("dog"), Name(0));
         // re-use gets the same entry: