Rework Diagnostics Folding

[johannes-wolf]

Changes

• Removed clone() from Expr.
• Made eval and ieval const again (prior diagnostics state).
• Diagnostics data is now stored in the diagnostics object instead of the AST nodes. We do not need to copy the whole AST prior evaluation anymore. Instead, AST nodes can query ctx.diag for a matching diagnostics data object.
• Expr now contains a stable and unique id()
• Moved ExprVisitor to its own files.

Because of the simplification of the diagnostics message generation, some corner-cases such as
or short-circuiting may produce no diagnostics for skipped branches and any could produce diagnostics even though another branch matched.

---

Note

Medium Risk
Touches core expression evaluation/parsing APIs (Expr becomes const-eval with stable ids, Context gains Diagnostics*) and rewires diagnostics collection/serialization, which could affect query evaluation results and diagnostic accuracy across complex expressions.

Overview
Reworks diagnostics collection to be external to the AST: expressions now have a stable ExprId, and runtime stats (field hits/evaluations and comparison operand types/results) are recorded via Context::diag into Diagnostics storage rather than mutating/cloning AST nodes.

Introduces a standalone recursive ExprVisitor (include/simfil/expression-visitor.h + src/expression-visitor.cpp) and updates all expressions, completion nodes, and the parser to be const-evaluated (eval/ieval) with accept(...) const. eval() now builds per-run diagnostics (prepareIndices + local merge) and diagnostics serialization format is updated accordingly; tests are adjusted to reflect the new message behavior and aggregation.

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[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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Autofix Details

Bugbot Autofix prepared fixes for both issues found in the latest run.

• ✅ Fixed: Always-true condition bypasses type intersection check
  • Replaced the always-true guard with an intersection.none() check so diagnostics are emitted only for non-overlapping operand types.
• ✅ Fixed: Non-portable unistd.h include in public header
  • Removed the unused POSIX-only <unistd.h> include from the public diagnostics header to restore portability.

Or push these changes by commenting:

@cursor push 74200e836f

Preview (74200e836f)

diff --git a/include/simfil/diagnostics.h b/include/simfil/diagnostics.h
--- a/include/simfil/diagnostics.h
+++ b/include/simfil/diagnostics.h
@@ -9,7 +9,6 @@
 
 #include <tl/expected.hpp>
 #include <optional>
-#include <unistd.h>
 #include <vector>
 #include <string>
 #include <memory>

diff --git a/src/diagnostics.cpp b/src/diagnostics.cpp
--- a/src/diagnostics.cpp
+++ b/src/diagnostics.cpp
@@ -165,7 +165,7 @@
         }
 
         const auto intersection = leftTypes.flags & rightTypes.flags;
-        if (true || intersection.none()) {
+        if (intersection.none()) {
             const auto allTrue = data.trueResults > 0 && data.falseResults == 0;
             const auto allFalse = data.falseResults > 0 && data.trueResults == 0;
             const auto prefix =

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[github-actions]

Test Results

 1 files  ±0   1 suites  ±0   6m 53s ⏱️ +2s
90 tests  - 1  90 ✅  - 1  0 💤 ±0  0 ❌ ±0 
95 runs   - 1  95 ✅  - 1  0 💤 ±0  0 ❌ ±0 

Results for commit 33c42ac. ± Comparison against base commit 9a3911b.

♻️ This comment has been updated with latest results.

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Cursor Bugbot has reviewed your changes and found 2 potential issues.

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[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Package	Line Rate	Branch Rate	Health
include.simfil	24%	10%	❌
include.simfil.model	75%	46%	➖
src	80%	47%	➖
src.model	82%	46%	✔
Summary	46% (7782 / 16915)	28% (4776 / 17361)	❌

[josephbirkner]

Well done 👍