make all Cycle fields private and provide public accessor methods

Author: mtshiba

benches/dataflow.rs

@@ -81,7 +81,7 @@ fn def_cycle_recover(
     value: Type,
     _def: Definition,
 ) -> Type {
-    cycle_recover(value, cycle.iteration)
+    cycle_recover(value, cycle.iteration())
 }
 
 fn use_cycle_initial(_db: &dyn Db, _id: salsa::Id, _use: Use) -> Type {
@@ -95,7 +95,7 @@ fn use_cycle_recover(
     value: Type,
     _use: Use,
 ) -> Type {
-    cycle_recover(value, cycle.iteration)
+    cycle_recover(value, cycle.iteration())
 }
 
 fn cycle_recover(value: Type, count: u32) -> Type {

src/cycle.rs

@@ -469,16 +469,34 @@ impl Iterator for CycleHeadIdsIterator<'_> {
 }
 
 /// The context that the cycle recovery function receives when a query cycle occurs.
-#[derive(Clone)]
 pub struct Cycle<'a> {
     /// An iterator that outputs the [`Id`]s of the current cycle heads.
-    /// This will always contain the [`Id`] of the query being processed by the current cycle recovery function,
-    /// but its position will depend on the query execution order.
-    pub head_ids: CycleHeadIdsIterator<'a>,
+    /// This always contains the [`Id`] of the current query but it can contain additional cycle head [`Id`]s
+    /// if this query is nested in an outer cycle or if it has nested cycles.
+    pub(crate) head_ids: CycleHeadIdsIterator<'a>,
     /// The [`Id`] of the query that the current cycle recovery function is processing.
-    pub id: Id,
+    pub(crate) id: Id,
     /// The counter of the current fixed point iteration.
-    pub iteration: u32,
+    pub(crate) iteration: u32,
+}
+
+impl Cycle<'_> {
+    /// An iterator that outputs the [`Id`]s of the current cycle heads.
+    /// This always contains the [`Id`] of the current query but it can contain additional cycle head [`Id`]s
+    /// if this query is nested in an outer cycle or if it has nested cycles.
+    pub fn head_ids(&self) -> CycleHeadIdsIterator<'_> {
+        self.head_ids.clone()
+    }
+
+    /// The [`Id`] of the query that the current cycle recovery function is processing.
+    pub fn id(&self) -> Id {
+        self.id
+    }
+
+    /// The counter of the current fixed point iteration.
+    pub fn iteration(&self) -> u32 {
+        self.iteration
+    }
 }
 
 #[derive(Debug)]

tests/cycle.rs

@@ -137,7 +137,7 @@ fn cycle_recover(
         .is_some_and(|val| val <= MIN_VALUE || val >= MAX_VALUE)
     {
         Value::OutOfBounds
-    } else if cycle.iteration > MAX_ITERATIONS {
+    } else if cycle.iteration() > MAX_ITERATIONS {
         Value::TooManyIterations
     } else {
         value

tests/dataflow.rs

@@ -85,7 +85,7 @@ fn def_cycle_recover(
     if &value == last_provisional_value {
         value
     } else {
-        cycle_recover(value, cycle.iteration)
+        cycle_recover(value, cycle.iteration())
     }
 }
 
@@ -103,7 +103,7 @@ fn use_cycle_recover(
     if &value == last_provisional_value {
         value
     } else {
-        cycle_recover(value, cycle.iteration)
+        cycle_recover(value, cycle.iteration())
     }
 }