about summary refs log tree commit diff
path: root/tvix/eval/src/value
diff options
context:
space:
mode:
Diffstat (limited to 'tvix/eval/src/value')
-rw-r--r--tvix/eval/src/value/attrs.rs122
-rw-r--r--tvix/eval/src/value/attrs/tests.rs30
-rw-r--r--tvix/eval/src/value/builtin.rs7
-rw-r--r--tvix/eval/src/value/function.rs6
-rw-r--r--tvix/eval/src/value/list.rs23
-rw-r--r--tvix/eval/src/value/mod.rs112
-rw-r--r--tvix/eval/src/value/thunk.rs4
7 files changed, 191 insertions, 113 deletions
diff --git a/tvix/eval/src/value/attrs.rs b/tvix/eval/src/value/attrs.rs
index 0551fe20d905..6802d195e8e2 100644
--- a/tvix/eval/src/value/attrs.rs
+++ b/tvix/eval/src/value/attrs.rs
@@ -18,7 +18,7 @@ use super::Value;
 #[cfg(test)]
 mod tests;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 enum AttrsRep {
     Empty,
     Map(BTreeMap<NixString, Value>),
@@ -71,7 +71,7 @@ impl AttrsRep {
 }
 
 #[repr(transparent)]
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct NixAttrs(AttrsRep);
 
 impl Display for NixAttrs {
@@ -97,58 +97,6 @@ impl Display for NixAttrs {
     }
 }
 
-impl PartialEq for NixAttrs {
-    fn eq(&self, other: &Self) -> bool {
-        match (&self.0, &other.0) {
-            (AttrsRep::Empty, AttrsRep::Empty) => true,
-
-            // It is possible to create an empty attribute set that
-            // has Map representation like so: ` { ${null} = 1; }`.
-            //
-            // Preventing this would incur a cost on all attribute set
-            // construction (we'd have to check the actual number of
-            // elements after key construction). In practice this
-            // probably does not happen, so it's better to just bite
-            // the bullet and implement this branch.
-            (AttrsRep::Empty, AttrsRep::Map(map)) | (AttrsRep::Map(map), AttrsRep::Empty) => {
-                map.is_empty()
-            }
-
-            // Other specialised representations (KV ...) definitely
-            // do not match `Empty`.
-            (AttrsRep::Empty, _) | (_, AttrsRep::Empty) => false,
-
-            (
-                AttrsRep::KV {
-                    name: n1,
-                    value: v1,
-                },
-                AttrsRep::KV {
-                    name: n2,
-                    value: v2,
-                },
-            ) => n1 == n2 && v1 == v2,
-
-            (AttrsRep::Map(map), AttrsRep::KV { name, value })
-            | (AttrsRep::KV { name, value }, AttrsRep::Map(map)) => {
-                if map.len() != 2 {
-                    return false;
-                }
-
-                if let (Some(m_name), Some(m_value)) =
-                    (map.get(&NixString::NAME), map.get(&NixString::VALUE))
-                {
-                    return name == m_name && value == m_value;
-                }
-
-                false
-            }
-
-            (AttrsRep::Map(m1), AttrsRep::Map(m2)) => m1 == m2,
-        }
-    }
-}
-
 #[cfg(feature = "arbitrary")]
 mod arbitrary {
     use super::*;
@@ -337,6 +285,72 @@ impl NixAttrs {
     pub(crate) fn from_map(map: BTreeMap<NixString, Value>) -> Self {
         NixAttrs(AttrsRep::Map(map))
     }
+
+    /// Compare `self` against `other` for equality using Nix equality semantics
+    pub fn nix_eq(&self, other: &Self) -> Result<bool, ErrorKind> {
+        match (&self.0, &other.0) {
+            (AttrsRep::Empty, AttrsRep::Empty) => Ok(true),
+
+            // It is possible to create an empty attribute set that
+            // has Map representation like so: ` { ${null} = 1; }`.
+            //
+            // Preventing this would incur a cost on all attribute set
+            // construction (we'd have to check the actual number of
+            // elements after key construction). In practice this
+            // probably does not happen, so it's better to just bite
+            // the bullet and implement this branch.
+            (AttrsRep::Empty, AttrsRep::Map(map)) | (AttrsRep::Map(map), AttrsRep::Empty) => {
+                Ok(map.is_empty())
+            }
+
+            // Other specialised representations (KV ...) definitely
+            // do not match `Empty`.
+            (AttrsRep::Empty, _) | (_, AttrsRep::Empty) => Ok(false),
+
+            (
+                AttrsRep::KV {
+                    name: n1,
+                    value: v1,
+                },
+                AttrsRep::KV {
+                    name: n2,
+                    value: v2,
+                },
+            ) => Ok(n1.nix_eq(n2)? && v1.nix_eq(v2)?),
+
+            (AttrsRep::Map(map), AttrsRep::KV { name, value })
+            | (AttrsRep::KV { name, value }, AttrsRep::Map(map)) => {
+                if map.len() != 2 {
+                    return Ok(false);
+                }
+
+                if let (Some(m_name), Some(m_value)) =
+                    (map.get(&NixString::NAME), map.get(&NixString::VALUE))
+                {
+                    return Ok(name.nix_eq(m_name)? && value.nix_eq(m_value)?);
+                }
+
+                Ok(false)
+            }
+
+            (AttrsRep::Map(m1), AttrsRep::Map(m2)) => {
+                if m1.len() != m2.len() {
+                    return Ok(false);
+                }
+
+                for (k, v1) in m1 {
+                    if let Some(v2) = m2.get(k) {
+                        if !v1.nix_eq(v2)? {
+                            return Ok(false);
+                        }
+                    } else {
+                        return Ok(false);
+                    }
+                }
+                Ok(true)
+            }
+        }
+    }
 }
 
 /// In Nix, name/value attribute pairs are frequently constructed from
diff --git a/tvix/eval/src/value/attrs/tests.rs b/tvix/eval/src/value/attrs/tests.rs
index e25b362d2565..e96d50855b84 100644
--- a/tvix/eval/src/value/attrs/tests.rs
+++ b/tvix/eval/src/value/attrs/tests.rs
@@ -1,15 +1,27 @@
-use proptest::prelude::ProptestConfig;
-
 use super::*;
-use crate::properties::eq_laws;
 
-eq_laws!(
-    NixAttrs,
-    ProptestConfig {
-        cases: 5,
-        ..Default::default()
+mod nix_eq {
+    use super::*;
+    use proptest::prelude::ProptestConfig;
+    use test_strategy::proptest;
+
+    #[proptest(ProptestConfig { cases: 5, ..Default::default() })]
+    fn reflexive(x: NixAttrs) {
+        assert!(x.nix_eq(&x).unwrap())
+    }
+
+    #[proptest(ProptestConfig { cases: 5, ..Default::default() })]
+    fn symmetric(x: NixAttrs, y: NixAttrs) {
+        assert_eq!(x.nix_eq(&y).unwrap(), y.nix_eq(&x).unwrap())
     }
-);
+
+    #[proptest(ProptestConfig { cases: 5, ..Default::default() })]
+    fn transitive(x: NixAttrs, y: NixAttrs, z: NixAttrs) {
+        if x.nix_eq(&y).unwrap() && y.nix_eq(&z).unwrap() {
+            assert!(x.nix_eq(&z).unwrap())
+        }
+    }
+}
 
 #[test]
 fn test_empty_attrs() {
diff --git a/tvix/eval/src/value/builtin.rs b/tvix/eval/src/value/builtin.rs
index 5d39a0a9f557..e79451392c2b 100644
--- a/tvix/eval/src/value/builtin.rs
+++ b/tvix/eval/src/value/builtin.rs
@@ -87,3 +87,10 @@ impl Display for Builtin {
         }
     }
 }
+
+/// Builtins are uniquely identified by their name
+impl PartialEq for Builtin {
+    fn eq(&self, other: &Self) -> bool {
+        self.name == other.name
+    }
+}
diff --git a/tvix/eval/src/value/function.rs b/tvix/eval/src/value/function.rs
index 758994504e45..c875b82aee05 100644
--- a/tvix/eval/src/value/function.rs
+++ b/tvix/eval/src/value/function.rs
@@ -9,7 +9,7 @@ use crate::{
     upvalues::{UpvalueCarrier, Upvalues},
 };
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Lambda {
     // name: Option<NixString>,
     pub(crate) chunk: Chunk,
@@ -30,14 +30,14 @@ impl Lambda {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct InnerClosure {
     pub lambda: Rc<Lambda>,
     upvalues: Upvalues,
 }
 
 #[repr(transparent)]
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Closure(Rc<RefCell<InnerClosure>>);
 
 impl Closure {
diff --git a/tvix/eval/src/value/list.rs b/tvix/eval/src/value/list.rs
index 19415c0d557f..8563c2256f07 100644
--- a/tvix/eval/src/value/list.rs
+++ b/tvix/eval/src/value/list.rs
@@ -1,6 +1,8 @@
 //! This module implements Nix lists.
 use std::fmt::Display;
 
+use crate::errors::ErrorKind;
+
 use super::Value;
 
 #[repr(transparent)]
@@ -20,6 +22,12 @@ impl Display for NixList {
     }
 }
 
+impl From<Vec<Value>> for NixList {
+    fn from(vs: Vec<Value>) -> Self {
+        Self(vs)
+    }
+}
+
 #[cfg(feature = "arbitrary")]
 mod arbitrary {
     use proptest::{
@@ -73,4 +81,19 @@ impl NixList {
     pub fn into_iter(self) -> std::vec::IntoIter<Value> {
         self.0.into_iter()
     }
+
+    /// Compare `self` against `other` for equality using Nix equality semantics
+    pub fn nix_eq(&self, other: &Self) -> Result<bool, ErrorKind> {
+        if self.len() != other.len() {
+            return Ok(false);
+        }
+
+        for (v1, v2) in self.iter().zip(other.iter()) {
+            if !v1.nix_eq(v2)? {
+                return Ok(false);
+            }
+        }
+
+        Ok(true)
+    }
 }
diff --git a/tvix/eval/src/value/mod.rs b/tvix/eval/src/value/mod.rs
index 594c1fd4735c..34dfbddfa167 100644
--- a/tvix/eval/src/value/mod.rs
+++ b/tvix/eval/src/value/mod.rs
@@ -24,7 +24,7 @@ pub use string::NixString;
 pub use thunk::Thunk;
 
 #[warn(variant_size_differences)]
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum Value {
     Null,
     Bool(bool),
@@ -253,6 +253,40 @@ impl Value {
 
     gen_is!(is_number, Value::Integer(_) | Value::Float(_));
     gen_is!(is_bool, Value::Bool(_));
+
+    /// Compare `self` against `other` for equality using Nix equality semantics
+    pub fn nix_eq(&self, other: &Self) -> Result<bool, ErrorKind> {
+        match (self, other) {
+            // Trivial comparisons
+            (Value::Null, Value::Null) => Ok(true),
+            (Value::Bool(b1), Value::Bool(b2)) => Ok(b1 == b2),
+            (Value::List(l1), Value::List(l2)) => l1.nix_eq(l2),
+            (Value::String(s1), Value::String(s2)) => Ok(s1 == s2),
+            (Value::Path(p1), Value::Path(p2)) => Ok(p1 == p2),
+
+            // Numerical comparisons (they work between float & int)
+            (Value::Integer(i1), Value::Integer(i2)) => Ok(i1 == i2),
+            (Value::Integer(i), Value::Float(f)) => Ok(*i as f64 == *f),
+            (Value::Float(f1), Value::Float(f2)) => Ok(f1 == f2),
+            (Value::Float(f), Value::Integer(i)) => Ok(*i as f64 == *f),
+
+            // Optimised attribute set comparison
+            (Value::Attrs(a1), Value::Attrs(a2)) => Ok(Rc::ptr_eq(a1, a2) || a1.nix_eq(a2)?),
+
+            // If either value is a thunk, the inner value must be
+            // compared instead. The compiler should ensure that
+            // thunks under comparison have been forced, otherwise it
+            // is a bug.
+            (Value::Thunk(lhs), Value::Thunk(rhs)) => Ok(*lhs.value() == *rhs.value()),
+            (Value::Thunk(lhs), rhs) => Ok(&*lhs.value() == rhs),
+            (lhs, Value::Thunk(rhs)) => Ok(lhs == &*rhs.value()),
+
+            // Everything else is either incomparable (e.g. internal
+            // types) or false.
+            // TODO(tazjin): mirror Lambda equality behaviour
+            _ => Ok(false),
+        }
+    }
 }
 
 impl Display for Value {
@@ -291,41 +325,6 @@ impl Display for Value {
     }
 }
 
-impl PartialEq for Value {
-    fn eq(&self, other: &Self) -> bool {
-        match (self, other) {
-            // Trivial comparisons
-            (Value::Null, Value::Null) => true,
-            (Value::Bool(b1), Value::Bool(b2)) => b1 == b2,
-            (Value::List(l1), Value::List(l2)) => l1 == l2,
-            (Value::String(s1), Value::String(s2)) => s1 == s2,
-            (Value::Path(p1), Value::Path(p2)) => p1 == p2,
-
-            // Numerical comparisons (they work between float & int)
-            (Value::Integer(i1), Value::Integer(i2)) => i1 == i2,
-            (Value::Integer(i), Value::Float(f)) => *i as f64 == *f,
-            (Value::Float(f1), Value::Float(f2)) => f1 == f2,
-            (Value::Float(f), Value::Integer(i)) => *i as f64 == *f,
-
-            // Optimised attribute set comparison
-            (Value::Attrs(a1), Value::Attrs(a2)) => Rc::ptr_eq(a1, a2) || { a1 == a2 },
-
-            // If either value is a thunk, the inner value must be
-            // compared instead. The compiler should ensure that
-            // thunks under comparison have been forced, otherwise it
-            // is a bug.
-            (Value::Thunk(lhs), Value::Thunk(rhs)) => *lhs.value() == *rhs.value(),
-            (Value::Thunk(lhs), rhs) => &*lhs.value() == rhs,
-            (lhs, Value::Thunk(rhs)) => lhs == &*rhs.value(),
-
-            // Everything else is either incomparable (e.g. internal
-            // types) or false.
-            // TODO(tazjin): mirror Lambda equality behaviour
-            _ => false,
-        }
-    }
-}
-
 fn type_error(expected: &'static str, actual: &Value) -> ErrorKind {
     ErrorKind::TypeError {
         expected,
@@ -335,16 +334,39 @@ fn type_error(expected: &'static str, actual: &Value) -> ErrorKind {
 
 #[cfg(test)]
 mod tests {
-    use crate::properties::eq_laws;
-    use proptest::prelude::ProptestConfig;
-
     use super::*;
 
-    eq_laws!(
-        Value,
-        ProptestConfig {
-            cases: 20,
-            ..Default::default()
+    #[test]
+    fn test_name() {}
+
+    mod nix_eq {
+        use super::*;
+        use proptest::prelude::ProptestConfig;
+        use test_strategy::proptest;
+
+        #[proptest(ProptestConfig { cases: 5, ..Default::default() })]
+        fn reflexive(x: Value) {
+            assert!(x.nix_eq(&x).unwrap())
+        }
+
+        #[proptest(ProptestConfig { cases: 5, ..Default::default() })]
+        fn symmetric(x: Value, y: Value) {
+            assert_eq!(x.nix_eq(&y).unwrap(), y.nix_eq(&x).unwrap())
+        }
+
+        #[proptest(ProptestConfig { cases: 5, ..Default::default() })]
+        fn transitive(x: Value, y: Value, z: Value) {
+            if x.nix_eq(&y).unwrap() && y.nix_eq(&z).unwrap() {
+                assert!(x.nix_eq(&z).unwrap())
+            }
+        }
+
+        #[test]
+        fn list_int_float_fungibility() {
+            let v1 = Value::List(NixList::from(vec![Value::Integer(1)]));
+            let v2 = Value::List(NixList::from(vec![Value::Float(1.0)]));
+
+            assert!(v1.nix_eq(&v2).unwrap())
         }
-    );
+    }
 }
diff --git a/tvix/eval/src/value/thunk.rs b/tvix/eval/src/value/thunk.rs
index 5098be186fa8..ed994ebd7d57 100644
--- a/tvix/eval/src/value/thunk.rs
+++ b/tvix/eval/src/value/thunk.rs
@@ -34,7 +34,7 @@ use crate::{
 use super::Lambda;
 
 /// Internal representation of the different states of a thunk.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 enum ThunkRepr {
     /// Thunk is closed over some values, suspended and awaiting
     /// execution.
@@ -51,7 +51,7 @@ enum ThunkRepr {
     Evaluated(Value),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Thunk(Rc<RefCell<ThunkRepr>>);
 
 impl Thunk {