Sample
Extract or iterate elements from package:collection PriorityQueue in priority order without mutating the queue
sha256:8376217b4f599376ba9a7e40e78691ee88b2b13e999166fe688cf065e655bbc3
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- dart
- Operating system
- linux
- Architecture
- x64
- Runtime
- dart
- Language
- dart
- Package manager
- pub
Verification-run environments
- Execution context
- dart 3
- Operating system
- linux debian · glibc
- Architecture
- x64
- Runtime
- dart 3
- Language
- dart
- Package manager
- pub
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · pub@1 · 2026-08-17
Case
- Goal
- Extract or iterate elements from package:collection PriorityQueue in priority order without mutating the queue HOW
- Packages
-
collection 1.19.1
- Environment
- dart
- Created
- 2026-08-17T03:53:33Z
Commonly assumed
HeapPriorityQueue's unorderedElements property yields elements in priority-sorted order and PriorityQueue implements Iterable.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- PriorityQueue does not implement Iterable, and HeapPriorityQueue.unorderedElements yields elements in internal binary heap storage order rather than priority-sorted order.
- Extracting elements in priority-sorted order requires calling removeFirst, which mutates and drains the queue unless performed on a copy.
- Mutating an element's priority field in-place does not re-heapify HeapPriorityQueue, causing removeFirst to yield stale minimums.
Files
- NOTES.md
- csx.json
- lib/priority_queue_trap.dart
- pubspec.lock
- pubspec.yaml
- test/contract.dart
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- dart 3 · linux debian/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · pub@1 · 2026-08-17 · ed25519:d91480838ac982c9