🐛 Clear classical bits in resetSimulationState

[rturrado]

Description

🤖 AI text below 🤖

resetSimulationState in src/backend/dd/DDSimDebug.cpp rebuilt the quantum state on reset but left ddsim->variables (the map of classical bit values) untouched. After a first run followed by reset, reading c[k] returned the value from the previous run rather than the initial false, and the next measure on the same bit looked like a no-op because the bit already held the value it would receive.

This PR iterates ddsim->variables with std::ranges::for_each over std::views::values after the quantum state rebuild and sets each boolValue back to false, matching how the quantum side is reset. Includes an end-to-end test that runs a program, verifies c[0] is true, calls resetSimulation, and verifies c[0] is false.

AI assistance

Commit messages, code changes, and this PR body were drafted with Claude Opus 4.7 via Claude Code. All content was reviewed and edited manually before submission.

Fixes#464.

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

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Run ID: 8accaf05-479d-413c-b81a-8bb7fb50c4e6

📥 Commits

Reviewing files that changed from the base of the PR and between 061ec7d and e077116.

📒 Files selected for processing (2)

• src/backend/dd/DDSimDebug.cpp
• test/test_custom_code.cpp

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📝 Summary

Summary by CodeRabbit

• Bug Fixes

  • Resetting a simulation now also clears all classical variables, setting them to false alongside the quantum state.
  • This ensures classical measurement results do not persist after a simulation reset.

• Tests

  • Added coverage verifying that measured classical bits are cleared when the simulation is reset.

Walkthrough

The reset operation now clears all classical variables after rebuilding the quantum state. A regression test verifies that a measured classical bit returns to false.

Changes

Classical State Reset

Layer / File(s)	Summary
Reset classical variables and verify behavior src/backend/dd/DDSimDebug.cpp, test/test_custom_code.cpp	resetSimulationState sets every classical variable to false. The new test verifies this after a measurement.

Priority: ➖ Normal — Schedule the reset fix because it restores classical bits to false for the CLI reset command and adds regression coverage for this medium-severity issue.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Severity of issue fixed: Medium

Merge Risk:⚪ Minimal · up to e0771

Simulation reset now restores classical bits to false alongside quantum state, with regression coverage confirming a measured true bit is cleared. The change is ready to merge.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The implementation resets all classical bit values to false after rebuilding the quantum state, and the added end-to-end test verifies this behavior. These changes satisfy issue #464 and remain within…
Out of Scope Changes check	✅ Passed	The source change and corresponding test are directly related to clearing classical bits during resetSimulationState. No unrelated changes are identified.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 2 files.
Title check	✅ Passed	The title clearly and concisely identifies the main change: clearing classical bits in resetSimulationState.
Description check	✅ Passed	The description explains the bug, motivation, implementation, linked issue, test coverage, AI assistance, and checklist status. It does not list dependencies explicitly, but this is non-critical and t…

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_{A rabbit measured one,
Then watched the reset run.
The quantum state turned new,
Classical bits did too.
False now waits in every slot.
Reset leaves no stale thought.}

_{Comment @coderabbitai help to get the list of available commands.}