bendns' repos / treaty
Diffstat (limited to 'src/protocol/visitor/value.rs')
-rw-r--r--src/protocol/visitor/value.rs67
1 files changed, 36 insertions, 31 deletions
diff --git a/src/protocol/visitor/value.rs b/src/protocol/visitor/value.rs
index 320d1ae..20438bb 100644
--- a/src/protocol/visitor/value.rs
+++ b/src/protocol/visitor/value.rs
@@ -5,13 +5,14 @@
use crate::{
any::{TypeName, TypeNameable},
nameable,
- protocol::{walker::HintMeta, ControlFlowFor, Effect, SyncEffect},
+ protocol::{walker::HintMeta, ControlFlowFor, Effect, SyncEffect, any_t},
+ hkt::hkt,
};
/// Trait object for the [`Value`] protocol.
///
/// Types implementing the [`Value`] protocol will implement this trait.
-pub trait Value<'a, 'ctx: 'a, T, E: Effect<'ctx> = SyncEffect> {
+pub trait Value<'ctx, T, E: Effect<'ctx> = SyncEffect> {
/// Visit a value of type `T`.
///
/// Use this to give a value to a visitor. Its expected that a walker
@@ -21,26 +22,30 @@ pub trait Value<'a, 'ctx: 'a, T, E: Effect<'ctx> = SyncEffect> {
/// If a [`ControlFlow::Break`] is returned then the walker
/// should stop walking as soon as possible as there has likely been
/// and error.
- fn visit(&'a mut self, value: T) -> ControlFlowFor<'a, 'ctx, E>;
+ fn visit<'a>(&'a mut self, value: T) -> ControlFlowFor<'a, 'ctx, E> where 'ctx: 'a;
}
nameable! {
- pub struct Name['a, 'ctx: 'a, T, E];
+ pub struct Name['a, 'ctx, T, E];
- impl [T::Name, E] for dyn Value<'a, 'ctx, T, E> + 'a where {
+ impl [T::Name, E] for dyn Value<'ctx, T, E> + 'a where {
T: TypeNameable<'a, 'ctx> + ?Sized,
E: Effect<'ctx>,
+ 'ctx: 'a,
}
- impl [T, E] where dyn Value<'a, 'ctx, T::Nameable, E> + 'a {
+ impl [T, E] where dyn Value<'ctx, T::Nameable, E> + 'a {
T: TypeName<'a, 'ctx> + ?Sized,
E: Effect<'ctx>,
+ 'ctx: 'a,
}
}
+hkt!((any_t): for<'a, 'ctx> pub KnownHkt => ());
+
// This enrolls the Value protocol into the walker hint system.
-impl<'a, 'ctx: 'a, T, E: Effect<'ctx>> HintMeta<'a, 'ctx> for dyn Value<'a, 'ctx, T, E> + 'a {
- type Known = ();
+impl<'a, 'ctx: 'a, T, E: Effect<'ctx>> HintMeta<'ctx> for dyn Value<'ctx, T, E> + 'a {
+ type KnownHkt = KnownHkt<'ctx>;
type Hint = ();
}
@@ -63,21 +68,21 @@ mod test {
fn visit() {
struct Visitor(Option<i32>);
- impl Value<'_, OwnedStatic<i32>> for Visitor {
- fn visit(
- &mut self,
+ impl<'ctx> Value<'ctx, OwnedStatic<i32>> for Visitor {
+ fn visit<'a>(
+ &'a mut self,
OwnedStatic(value): OwnedStatic<i32>,
- ) -> core::ops::ControlFlow<()> {
+ ) -> core::ops::ControlFlow<()> where 'ctx: 'a {
self.0 = Some(value);
ControlFlow::Continue(())
}
}
- impl Value<'_, BorrowedStatic<'_, i32>> for Visitor {
- fn visit(
- &mut self,
- BorrowedStatic(value): BorrowedStatic<'_, i32>,
- ) -> core::ops::ControlFlow<()> {
+ impl<'ctx> Value<'ctx, BorrowedStatic<'ctx, i32>> for Visitor {
+ fn visit<'a>(
+ &'a mut self,
+ BorrowedStatic(value): BorrowedStatic<'ctx, i32>,
+ ) -> core::ops::ControlFlow<()> where 'ctx: 'a {
self.0 = Some(*value);
ControlFlow::Continue(())
}
@@ -85,9 +90,9 @@ mod test {
any_trait! {
impl['a, 'ctx] Visitor = [
- dyn Value<'a, OwnedStatic<i32>> + 'a,
- dyn Value<'a, BorrowedStatic<'ctx, i32>> + 'a,
- ];
+ dyn Value<'ctx, OwnedStatic<i32>> + 'a,
+ dyn Value<'ctx, BorrowedStatic<'ctx, i32>> + 'a,
+ ]
}
let mut v = Visitor(None);
@@ -112,11 +117,11 @@ mod test {
fn visit_borrowed() {
struct Visitor<'ctx>(Option<&'ctx mut String>);
- impl<'a, 'ctx> Value<'a, BorrowedMutStatic<'ctx, String>> for Visitor<'ctx> {
- fn visit(
+ impl<'ctx> Value<'ctx, BorrowedMutStatic<'ctx, String>> for Visitor<'ctx> {
+ fn visit<'a>(
&'a mut self,
BorrowedMutStatic(value): BorrowedMutStatic<'ctx, String>,
- ) -> ControlFlow<()> {
+ ) -> ControlFlow<()> where 'ctx: 'a {
self.0 = Some(value);
ControlFlow::Continue(())
}
@@ -124,8 +129,8 @@ mod test {
any_trait! {
impl['a, 'ctx] Visitor<'ctx> = [
- dyn Value<'a, BorrowedMutStatic<'ctx, String>> + 'a,
- ];
+ dyn Value<'ctx, BorrowedMutStatic<'ctx, String>> + 'a,
+ ]
}
let mut v = Visitor(None);
@@ -145,11 +150,11 @@ mod test {
fn visit_borrowed_unsized() {
struct Visitor<'ctx>(Option<&'ctx str>);
- impl<'a, 'ctx> Value<'a, BorrowedStatic<'ctx, str>> for Visitor<'ctx> {
- fn visit(
+ impl<'ctx> Value<'ctx, BorrowedStatic<'ctx, str>> for Visitor<'ctx> {
+ fn visit<'a>(
&'a mut self,
BorrowedStatic(value): BorrowedStatic<'ctx, str>,
- ) -> ControlFlow<()> {
+ ) -> ControlFlow<()> where 'ctx: 'a {
self.0 = Some(value);
ControlFlow::Continue(())
}
@@ -157,8 +162,8 @@ mod test {
any_trait! {
impl['a, 'ctx] Visitor<'ctx> = [
- dyn Value<'a, BorrowedStatic<'ctx, str>> + 'a,
- ];
+ dyn Value<'ctx, BorrowedStatic<'ctx, str>> + 'a,
+ ]
}
let mut v = Visitor(None);
@@ -166,7 +171,7 @@ mod test {
let y = String::from("abc");
let object: &mut dyn AnyTrait<'_> = &mut v;
object
- .upcast_mut::<dyn Value<'_, BorrowedStatic<'_, str>>>()
+ .upcast_mut::<dyn Value<'_, BorrowedStatic<'_, str>> + '_>()
.unwrap()
.visit(BorrowedStatic(&y));