✨ Support non-equality comparators in classic-controlled if - #456
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rturrado wants to merge 8 commits into
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✨ Support non-equality comparators in classic-controlled if#456rturrado wants to merge 8 commits into
rturrado wants to merge 8 commits into
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`test_custom_code` already exercises `if(c==1) { x q[0]; x q[1]; }` on a single physical line.
Add the same case with a real multi-line block, since issue munich-quantum-toolkit#168 hints that this form is not accepted.
It already is; the new test locks that in.
Assisted-by: Claude Opus 4.7 via Claude Code
The debugger only accepted `==` in classic-controlled `if` conditions and threw at runtime when mqt-core's `IfElseOperation` reported any other comparison kind, even though mqt-core supports the full set. Extend `ClassicCondition` with a `qc::ComparisonKind` field so the parser carries the operator through and evaluate the condition with the matching comparison in the DD backend. Add one test per new operator; each mixes a case that triggers with one that does not, so the operator is actually applied and not read as always-true by accident. Part of munich-quantum-toolkit#168. Assisted-by: Claude Opus 4.7 via Claude Code
The comparator change already handles conditions on a single bit like `if(c[0] > 0) ...` through the existing bracket path in the parser and mqt-core's `getControlBit()`. Add a test to lock that in and to cover the single-bit branch of the DD backend with a non-`Eq` comparator. Assisted-by: Claude Opus 4.7 via Claude Code
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@coderabbitai full review |
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📝 SummarySummary by CodeRabbit
WalkthroughThe change adds comparison-kind storage and parsing for classic conditions. The DD simulator evaluates equality and non-equality comparisons in both execution directions. Custom-code tests cover multiline blocks, six operators, and single-bit conditions. ChangesClassic comparison conditions
Estimated code review effort: 3 (Moderate) | ~20 minutes Merge Risk: 🔵 Low · up to Classic conditions now support non-equality comparisons, but reverse stepping after these conditions is not covered by regression tests. A defect could affect debugger reverse execution without being detected by the current suite. Sequence Diagram(s)sequenceDiagram
participant CustomCode
participant CodePreprocessing
participant DDSimDebug
participant Statevector
CustomCode->>CodePreprocessing: parse classic condition
CodePreprocessing-->>DDSimDebug: return register, expected value, comparison kind
DDSimDebug->>DDSimDebug: apply comparison
DDSimDebug->>Statevector: execute selected if-else branch
Statevector-->>CustomCode: return simulation result
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🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
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Inline comments:
In `@test/test_custom_code.cpp`:
- Around line 124-213: Add a reverse-execution test alongside the non-equality
condition tests that executes a non-equality if condition, captures the state
before and after it, calls stepBackward, and verifies the state is restored to
the pre-condition state. Use the existing CustomCodeTest setup and state-vector
comparison patterns, ensuring the test specifically exercises the updated
reverse-execution branch.
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📒 Files selected for processing (4)
include/common/parsing/CodePreprocessing.hppsrc/backend/dd/DDSimDebug.cppsrc/common/parsing/CodePreprocessing.cpptest/test_custom_code.cpp
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Four small changes that satisfy the checks reported by the `cpp-linter` job on the PR, all in `parseClassicConditionExpression`: - Directly include `ir/operations/IfElseOperation.hpp` in the `.cpp`. The header was only pulled in transitively via `CodePreprocessing.hpp`, which `misc-include-cleaner` rejects. - Rename the operator table `operators` to `OPERATORS`. The project's `readability-identifier-naming` rule requires `StaticConstantCase = UPPER_CASE`. - Use designated initializers in the `OPERATORS` array (`.text = ..., .kind = ...`). - Qualify the `std::ranges::find_if` result as `const auto* const found`. The iterator over a plain `std::array` is a raw pointer, so `readability-qualified-auto` wants the qualification. Assisted-by: Claude Opus 4.7 via Claude Code
The per-operator tests added earlier only call `runSimulation`, so the backward-step branch of the DD backend's `if` handling (also updated in the comparator commit) had no coverage. Add one test that runs forward, then calls `stepBackward` and verifies that the `x q[1]` applied by `if(c > 0)` is correctly undone. Addresses a CodeRabbit review comment on the PR. Assisted-by: Claude Opus 4.7 via Claude Code
The iterator returned by `std::ranges::find_if` over `std::array` is a raw pointer on libstdc++ and libc++, but a class type (`_Array_const_iterator`) on MSVC STL. The earlier `const auto* const found` compiled on Linux; on MSVC it failed to deduce and cascaded into "cannot be used before it is initialized" errors on every variable that read from `found`. Replace the `find_if` + iterator pattern with a range-based `for` that stores the match in a `std::optional<OperatorMatch>`. No iterator escapes the loop, so the code compiles cleanly under all three standard libraries, and no clang-tidy check fires. Assisted-by: Claude Opus 4.7 via Claude Code
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🤖 AI text below 🤖 A few follow-up ideas that came up while working on this PR but fall outside the scope of #168. Debugger core
CLI frontend
Happy to open any of these as separate issues if you'd like. Let me know. |
rturrado
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September 5, 2026 21:45
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Description
🤖 AI text below 🤖
Let the debugger evaluate classic-controlled
ifconditions with any of the six comparison operators supported bymqt-core, not just==.What this PR covers (from #168)
!=,<,<=,>,>=) inif (cond)conditions.Before this PR the DD backend threw at runtime for anything other than
==, even thoughmqt-core'sIfElseOperationalready models all six.if { ... }body.The issue suggests this form is not accepted, but it seems it already is; the new test locks that in.
Split into three atomic commits: multi-line body regression test, comparator change with per-operator tests, and a single-bit-condition test on top.
Not covered here (from or around #168)
if { ... }body.Today the whole block is a single
Instructionfrom the stepper's point of view, so step-over highlights all lines together and breakpoints cannot land inside. This would needpreprocessCodeto expand a classic-controlled block into sub-instructions, similar to how gate bodies are handled.c[a:b]used as the condition operand).I have not explored whether
mqt-coreparses this form or how it would surface inIfElseOperation. Single-bit checks likeif (c[0] > 0)already work as of this PR; seeIfElseOperationSingleBit.Question
Do you prefer that I address these in follow-up PRs, or that I extend this one?
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.
Related to #168.
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