Replace vector by enum set

Author: Hendrik van Antwerpen

stack-graphs/Cargo.toml

@@ -24,6 +24,7 @@ test = false
 bitvec = "1.0"
 controlled-option = "0.4"
 either = "1.6"
+enumset = "1.0"
 fxhash = "0.2"
 itertools = "0.10"
 libc = "0.2"

stack-graphs/src/cycles.rs

@@ -31,6 +31,7 @@
 
 use std::collections::HashMap;
 
+use enumset::EnumSet;
 use smallvec::SmallVec;
 
 use crate::arena::Handle;
@@ -186,8 +187,8 @@ impl<A: Appendable + Clone> AppendingCycleDetector<A> {
         partials: &mut PartialPaths,
         ctx: &mut A::Ctx,
         appendables: &mut Appendables<A>,
-    ) -> Result<Vec<Cyclicity>, PathResolutionError> {
-        let mut cycles = Vec::new();
+    ) -> Result<EnumSet<Cyclicity>, PathResolutionError> {
+        let mut cycles = EnumSet::new();
 
         let end_node = match self.appendages.clone().pop_front(appendables) {
             Some(appendage) => appendage.end_node(ctx),
@@ -227,7 +228,7 @@ impl<A: Appendable + Clone> AppendingCycleDetector<A> {
             prefix_path.ensure_no_overlapping_variables(partials, &cyclic_path);
             prefix_path.concatenate(graph, partials, &cyclic_path)?;
             if let Some(cyclicity) = prefix_path.is_cyclic(graph, partials) {
-                cycles.push(cyclicity);
+                cycles |= cyclicity;
             }
             maybe_cyclic_path = Some(prefix_path);
         }

stack-graphs/src/partial.rs

@@ -40,6 +40,7 @@ use std::num::NonZeroU32;
 
 use controlled_option::ControlledOption;
 use controlled_option::Niche;
+use enumset::EnumSetType;
 use smallvec::SmallVec;
 
 use crate::arena::Deque;
@@ -2229,7 +2230,7 @@ impl PartialPath {
     }
 }
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Debug, EnumSetType)]
 pub enum Cyclicity {
     /// The path can be freely concatenated to itself.
     Free,

stack-graphs/tests/it/cycles.rs

@@ -5,6 +5,7 @@
 // Please see the LICENSE-APACHE or LICENSE-MIT files in this distribution for license details.
 // ------------------------------------------------------------------------------------------------
 
+use enumset::enum_set;
 use stack_graphs::cycles::Appendables;
 use stack_graphs::cycles::AppendingCycleDetector;
 use stack_graphs::graph::StackGraph;
@@ -182,7 +183,7 @@ fn finding_simple_identity_cycle_is_detected() {
         }
         cd.append(&mut edges, edge(foo_def, r, 0));
         assert_eq!(
-            vec![Cyclicity::StrengthensPostcondition],
+            enum_set![Cyclicity::StrengthensPostcondition],
             cd.is_cyclic(&graph, &mut partials, ctx, &mut edges)
                 .unwrap()
         );
@@ -227,7 +228,7 @@ fn stitching_simple_identity_cycle_is_detected() {
             AppendingCycleDetector::from(&mut paths, p0.into());
         cd.append(&mut paths, p1.into());
         assert_eq!(
-            vec![Cyclicity::StrengthensPostcondition],
+            enum_set![Cyclicity::StrengthensPostcondition],
             cd.is_cyclic(&graph, &mut partials, &mut db, &mut paths)
                 .unwrap()
         );
@@ -275,7 +276,7 @@ fn finding_composite_identity_cycle_is_detected() {
         }
         cd.append(&mut edges, edge(bar_ref, s, 0));
         assert_eq!(
-            vec![Cyclicity::StrengthensPostcondition],
+            enum_set![Cyclicity::StrengthensPostcondition],
             cd.is_cyclic(&graph, &mut partials, ctx, &mut edges)
                 .unwrap()
         );
@@ -323,7 +324,7 @@ fn stitching_composite_identity_cycle_is_detected() {
             AppendingCycleDetector::from(&mut paths, p0.into());
         cd.append(&mut paths, p1.into());
         assert_eq!(
-            vec![Cyclicity::StrengthensPostcondition],
+            enum_set![Cyclicity::StrengthensPostcondition],
             cd.is_cyclic(&graph, &mut partials, &mut db, &mut paths)
                 .unwrap()
         );