Stuff and bother.

src/syntax/name.rs

@@ -1,12 +1,14 @@
 use crate::syntax::Location;
+#[cfg(test)]
+use internment::ArcIntern;
 use std::cmp;
 use std::fmt;
-use std::hash;
+use std::hash::{Hash, Hasher};
 use std::sync::atomic::{AtomicU64, Ordering};
 
 static IDENTIFIER_COUNTER: AtomicU64 = AtomicU64::new(0);
 
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct Name {
     printable: String,
     identifier: u64,
@@ -21,8 +23,8 @@ impl cmp::PartialEq for Name {
 
 impl cmp::Eq for Name {}
 
-impl hash::Hash for Name {
-    fn hash<H: hash::Hasher>(&self, state: &mut H) {
+impl Hash for Name {
+    fn hash<H: Hasher>(&self, state: &mut H) {
         self.identifier.hash(state);
     }
 }
@@ -66,3 +68,89 @@ impl Name {
         self.location.as_ref()
     }
 }
+
+#[test]
+fn equality() {
+    let file = ArcIntern::new("/foo.bang".into());
+    let loc1 = Location::new(&file, 0..3);
+    let loc2 = Location::new(&file, 9..12);
+
+    assert_ne!(Name::gensym("x"), Name::gensym("x"));
+    assert_ne!(Name::new(loc1.clone(), "x"), Name::new(loc1.clone(), "x"));
+    assert_eq!(
+        Name {
+            printable: "x".into(),
+            identifier: 5,
+            location: Some(loc1.clone())
+        },
+        Name {
+            printable: "x".into(),
+            identifier: 5,
+            location: Some(loc2.clone())
+        }
+    );
+    assert_eq!(
+        Name {
+            printable: "x".into(),
+            identifier: 5,
+            location: Some(loc1.clone())
+        },
+        Name {
+            printable: "x".into(),
+            identifier: 5,
+            location: None
+        }
+    );
+    assert_eq!(
+        Name {
+            printable: "x".into(),
+            identifier: 5,
+            location: Some(loc1.clone())
+        },
+        Name {
+            printable: "y".into(),
+            identifier: 5,
+            location: None
+        }
+    );
+}
+
+#[test]
+fn hashing() {
+    let file = ArcIntern::new("/foo.bang".into());
+    let loc1 = Location::new(&file, 0..3);
+    let loc2 = Location::new(&file, 9..12);
+
+    let x1 = Name {
+        printable: "x".into(),
+        identifier: 1,
+        location: Some(loc1),
+    };
+    let mut x2 = Name {
+        printable: "x".into(),
+        identifier: 2,
+        location: Some(loc2),
+    };
+    let y1 = Name {
+        printable: "y".into(),
+        identifier: 1,
+        location: None,
+    };
+
+    let run_hash = |name: &Name| {
+        let mut hash = std::hash::DefaultHasher::new();
+        name.hash(&mut hash);
+        hash.finish()
+    };
+
+    let hash_x1 = run_hash(&x1);
+    let hash_x2 = run_hash(&x2);
+    let hash_y1 = run_hash(&y1);
+
+    assert_ne!(hash_x1, hash_x2);
+    assert_eq!(hash_x1, hash_y1);
+
+    x2.bind_to(&x1);
+    let rehashed_x2 = run_hash(&x2);
+    assert_eq!(hash_x1, rehashed_x2);
+}