Sample
collection 1.19.1: show how omitting the queue comparator changes element priority semantics
Verified sample for pub collection 1.19.1: show how omitting the queue comparator changes element priority semantics. The contract ran on dart 3 · linux…
sha256:4c5ea45d1953eb6c9bee6f0124f6cac8618d0a6fde9ad4c2d477cdea982b3a36
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MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
dart linux x64 dart dart pub
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| dart 3 · linux debian/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · pub@1 |
2026-08-16 |
| dart 3 · linux debian/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · pub@1 |
2026-08-18 |
Case
HOW- Goal
- show how omitting the queue comparator changes element priority semantics
- Packages
- Symbols
-
- PriorityQueue
- PriorityQueue.PriorityQueue
- HeapPriorityQueue
- Environment
- dart
- Created
- 2026-08-17T02:04:34Z
Contract
- A `PriorityQueue` without a comparator argument is a min-heap, so `removeFirst()` returns 1 before 3 from [3, 1, 5].
- Removing from a default `PriorityQueue<int>` created with [3, 1, 5] yields 1 first, then 3, then 5.
- Providing `(a, b) => b.compareTo(a)` to `PriorityQueue` flips default priority and returns 5 before 1 for the same values.
Files
- NOTES.md
- csx.json
- pubspec.lock
- pubspec.yaml
- test/contract.dart