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authorNadrieril2019-08-20 18:03:59 +0200
committerNadrieril2019-08-20 18:03:59 +0200
commit4f1f37cfc115510500e83d2dfbfa8ed7ddeae74a (patch)
tree77c743b9c55afbbb5966a3c90614c6d3d257813d /dhall/src/core
parenta506632b27b287d1bf898e2f77ae09a56902474c (diff)
Introduce a new enum to store either a Value or a ValueF
Diffstat (limited to 'dhall/src/core')
-rw-r--r--dhall/src/core/value.rs54
-rw-r--r--dhall/src/core/valuef.rs9
2 files changed, 57 insertions, 6 deletions
diff --git a/dhall/src/core/value.rs b/dhall/src/core/value.rs
index 5055ac2..25fcaae 100644
--- a/dhall/src/core/value.rs
+++ b/dhall/src/core/value.rs
@@ -44,6 +44,14 @@ struct ValueInternal {
#[derive(Clone)]
pub struct Value(Rc<RefCell<ValueInternal>>);
+/// When a function needs to return either a freshly created ValueF or an existing Value, but
+/// doesn't want to convert both to the same thing, either to avoid unnecessary allocations or to
+/// avoid loss of typ information.
+pub enum VoVF {
+ Value(Value),
+ ValueF(ValueF),
+}
+
impl ValueInternal {
fn into_value(self) -> Value {
Value(Rc::new(RefCell::new(self)))
@@ -56,7 +64,8 @@ impl ValueInternal {
take_mut::take(self, |vint| match &vint.form {
Unevaled => ValueInternal {
form: WHNF,
- value: normalize_whnf(vint.value),
+ // TODO: thunk chaining
+ value: normalize_whnf(vint.value).into_whnf(),
ty: vint.ty,
},
// Already in WHNF
@@ -166,6 +175,9 @@ impl Value {
pub(crate) fn into_typed(self) -> Typed {
Typed::from_value(self)
}
+ pub(crate) fn into_vovf(self) -> VoVF {
+ VoVF::Value(self)
+ }
/// Mutates the contents. If no one else shares this, this avoids a RefCell lock.
fn mutate_internal(&mut self, f: impl FnOnce(&mut ValueInternal)) {
@@ -212,8 +224,8 @@ impl Value {
self.as_nf().normalize_to_expr_maybe_alpha(alpha)
}
- pub(crate) fn app(&self, th: Value) -> ValueF {
- apply_any(self.clone(), th)
+ pub(crate) fn app(&self, v: Value) -> VoVF {
+ apply_any(self.clone(), v)
}
pub(crate) fn get_type(&self) -> Result<Cow<'_, Value>, TypeError> {
@@ -221,6 +233,42 @@ impl Value {
}
}
+impl VoVF {
+ pub fn into_whnf(self) -> ValueF {
+ match self {
+ VoVF::Value(v) => v.to_whnf(),
+ VoVF::ValueF(v) => v,
+ }
+ }
+ pub(crate) fn into_value_untyped(self) -> Value {
+ match self {
+ VoVF::Value(v) => v,
+ VoVF::ValueF(v) => v.into_value_untyped(),
+ }
+ }
+ pub(crate) fn into_value_with_type(self, t: Value) -> Value {
+ match self {
+ // TODO: check type with debug_assert ?
+ VoVF::Value(v) => v,
+ VoVF::ValueF(v) => v.into_value_with_type(t),
+ }
+ }
+ pub(crate) fn into_value_simple_type(self) -> Value {
+ match self {
+ // TODO: check type with debug_assert ?
+ VoVF::Value(v) => v,
+ VoVF::ValueF(v) => v.into_value_simple_type(),
+ }
+ }
+
+ pub(crate) fn app(self, x: Value) -> Self {
+ match self {
+ VoVF::Value(v) => v.app(x),
+ VoVF::ValueF(v) => v.into_value_untyped().app(x),
+ }
+ }
+}
+
impl Shift for Value {
fn shift(&self, delta: isize, var: &AlphaVar) -> Option<Self> {
Some(Value(self.0.shift(delta, var)?))
diff --git a/dhall/src/core/valuef.rs b/dhall/src/core/valuef.rs
index e9049c7..80978a7 100644
--- a/dhall/src/core/valuef.rs
+++ b/dhall/src/core/valuef.rs
@@ -5,7 +5,7 @@ use dhall_syntax::{
NaiveDouble, Natural,
};
-use crate::core::value::Value;
+use crate::core::value::{Value, VoVF};
use crate::core::var::{AlphaLabel, AlphaVar, Shift, Subst};
use crate::phase::{Normalized, NormalizedSubExpr};
@@ -56,6 +56,9 @@ impl ValueF {
pub(crate) fn into_value_simple_type(self) -> Value {
Value::from_valuef_simple_type(self)
}
+ pub(crate) fn into_vovf(self) -> VoVF {
+ VoVF::ValueF(self)
+ }
/// Convert the value to a fully normalized syntactic expression
pub(crate) fn normalize_to_expr(&self) -> NormalizedSubExpr {
@@ -257,8 +260,8 @@ impl ValueF {
}
/// Apply to a value
- pub fn app(self, th: Value) -> ValueF {
- Value::from_valuef_untyped(self).app(th)
+ pub fn app(self, v: Value) -> VoVF {
+ self.into_vovf().app(v)
}
pub fn from_builtin(b: Builtin) -> ValueF {