BE-315: HashQL: Add GraphReadFilter source variant to MIR

[indietyp]

🌟 What is the purpose of this PR?

Add support for graph read filter closures in MIR by introducing a new GraphReadFilter source variant. This allows the compiler to properly handle and optimize filter closures used in graph read operations.

🔍 What does this change?

• Add a new Source::GraphReadFilter variant to represent MIR generated from filter closures in graph read operations
• Update the transform_closure method to accept a source parameter instead of constructing it internally
• Modify the inlining analysis to never inline graph read filters
• Replace the filters method in the callgraph with direct source type checking
• Update pretty printing to properly display graph read filters
• Ensure graph read filters are properly handled throughout the MIR pipeline

Pre-Merge Checklist 🚀

🚢 Has this modified a publishable library?

This PR:

• does not modify any publishable blocks or libraries, or modifications do not need publishing

📜 Does this require a change to the docs?

The changes in this PR:

• are internal and do not require a docs change

🕸️ Does this require a change to the Turbo Graph?

The changes in this PR:

• do not affect the execution graph

🛡 What tests cover this?

• Existing MIR tests should cover this functionality

❓ How to test this?

1. Checkout the branch
2. Run tests that involve graph read operations with filters
3. Confirm that filters are properly handled and not inlined

[cursor]

PR Summary

Medium Risk
Touches MIR reification and inlining decisions; behavior changes are scoped but could affect optimization correctness/perf for graph read pipelines.

Overview
Introduces a new MIR body origin Source::GraphReadFilter(HirId) to explicitly represent closure bodies used as graph read |> filter(...) predicates.

Updates MIR reification to tag graph-read filter closures with this new source (by threading an explicit Source through transform_closure/lower_closure) and treats these bodies as fat-pointer closures for environment handling.

Adjusts the inliner to never inline GraphReadFilter bodies and to identify “filter” functions by body.source rather than via a callgraph filters() query. Pretty-printing and UI test snapshots are updated to render filters as {graph::read::filter@...} instead of generic {closure@...}.

^{Written by Cursor Bugbot for commit 1406e8d. This will update automatically on new commits. Configure here.}

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
hash	Ready	Preview, Comment	Feb 6, 2026 3:55pm

3 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
hashdotdesign	Ignored	Preview	Feb 6, 2026 3:55pm
hashdotdesign-tokens	Ignored	Preview	Feb 6, 2026 3:55pm
petrinaut	Skipped		Feb 6, 2026 3:55pm

[indietyp]

• BE-394: HashQL: Rework BitMatrix and SparseBitMatrix #8408
• BE-372: HashQL: Add traversal-aware liveness analysis for optimizing entity projections #8363
• BE-304: HashQL: Terminator placement based on capabilities #8359
• BE-303: HashQL: Split MIR basic blocks by target support #8354
• BE-364: HashQL: Rework symbol representation for speed and size #8343
• BE-360: HashQL: Rework compiletest UI #8340
• BE-302: HashQL: Statement cost analysis for execution target placement #8339
• BE-317: HashQL: Implement TraversalExtraction pass #8331
• BE-315: HashQL: Add GraphReadFilter source variant to MIR #8323 👈 (View in Graphite)
• BE-301: HashQL: Implement size estimation analysis for MIR #8278
• BE-273: HashQL: Profile and benchmark MIR interpreter #8251
• BE-272: HashQL: Add numeric addition and subtraction operators to MIR #8250
• BE-257: HashQL: Implement MIR interpreter with runtime value representation #8245
• BE-271: HashQL: Implement PostInline pass #8240
• BE-269: HashQL: Move PreInline out into Canonicalization pass #8239
• BE-268: HashQL: Rename PreInlining to PreInline for consistency #8238
• BE-270: HashQL: Optimize empty tuples to unit constants in MIR #8237
• BE-197: Implement MIR inline pass for HashQL #8236
• BE-267: Use bump scopes instead of full resets across transformation passes #8234
• BE-266: HashQL: Implement PreInlining pass for MIR optimization #8233
• BE-265: HashQL: Make CopyPropagation aware of local re-assignments #8231
• BE-264: HashQL: Rename SROA to ForwardSubstitution for better semantic clarity #8230
• BE-263: HashQL: add body! macro for declarative MIR construction in tests #8229
• BE-261: HashQL: Implement Administrative Reduction pass for MIR #8227
• BE-262: HashQL: Do not intern empty slices #8223
• BE-260: HashQL: Switch to bump allocator with scoping support #8218
• BE-259: HashQL: Add benchmarks for type system operations #8216
• BE-227: HashQL: Implement call graph analysis for MIR #8214
• BE-258: HashQL: Add Changed enum to track MIR transformation pass modifications #8210
• BE-255: HashQL: Implement Copy Propagation (CP) pass for MIR #8207
• BE-231: HashQL: Add InstSimplify pass for MIR instruction simplification and constant folding #8206
• BE-254: Add CodSpeed benchmarking for HashQL MIR transformation passes #8204
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

Your organization requires reapproval when changes are made, so Graphite has dismissed approvals. See the output of git range-diff at https://github.com/hashintel/hash/actions/runs/21745833243

Your organization requires reapproval when changes are made, so Graphite has dismissed approvals. See the output of git range-diff at https://github.com/hashintel/hash/actions/runs/21756655265

[graphite-app]

Merge activity

• Feb 6, 3:50 PM UTC: Graphite rebased this pull request, because this pull request is set to merge when ready.