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[Repo Assist] perf/refactor: convert ILFieldDefs/ILEventDefs/ILPropertyDefs to concrete classes with lazy name-lookup caches#502

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dsyme merged 2 commits intomasterfrom
repo-assist/improve-il-defs-caches-20260413-74713908d4881b11
Apr 13, 2026
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[Repo Assist] perf/refactor: convert ILFieldDefs/ILEventDefs/ILPropertyDefs to concrete classes with lazy name-lookup caches#502
dsyme merged 2 commits intomasterfrom
repo-assist/improve-il-defs-caches-20260413-74713908d4881b11

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Summary

This PR converts ILFieldDefs, ILEventDefs, and ILPropertyDefs from abstract interfaces to concrete classes, mirroring the existing ILMethodDefs pattern. It adds lazy O(1) name-lookup caches throughout and makes entries truly lazy (computed at most once per type).

Background

Previously these three types were abstract interfaces:

// Before — computed on every .Entries access; linear O(n) name lookups everywhere
type ILFieldDefs =
    abstract Entries: ILFieldDef[]

Every name-based lookup (GetField, GetPropertyImpl, GetEvent, GetEnumUnderlyingType) called Array.tryFind — an O(n) linear scan. Additionally, seekReadEvents and seekReadProperties recomputed the entries array on every .Entries access (the binary reader range scan ran again each time).

Changes

Concrete classes with lazy dict caches — mirroring ILMethodDefs:

type ILFieldDefs(larr: Lazy<ILFieldDef[]>) =
    let lmap = lazy (
        let d = Dictionary<string, ILFieldDef>()
        for f in larr.Force() do d.[f.Name] <- f
        d)
    member __.Entries = larr.Force()
    member __.TryFindByName nm =
        let scc, v = lmap.Value.TryGetValue(nm) in if scc then Some v else None

Similarly for ILEventDefs and ILPropertyDefs.

Entries are now truly lazyseekReadEvents/seekReadProperties previously re-ran the range scan on every .Entries call. Now the lazy constructor caches after first access.

O(1) lookups in TypeSymbol and TargetTypeDefinition:

  • TypeSymbol.GetField/GetPropertyImpl/GetEvent (generic instantiations): now use TryFindByName instead of Array.tryFind
  • TargetTypeDefinition.GetField/GetPropertyImpl/GetEvent: new lazy fieldDefsMap/propDefsMap/eventDefsMap dictionaries over the wrapped reflection objects
  • TargetTypeDefinition.GetEnumUnderlyingType: uses TryFindByName for the "value__" field

All creation sites updated: empty constants, seekReadFields/seekReadEvents/seekReadProperties, and ProvidedTypeBuilder.

Trade-offs

  • Slightly higher memory use per loaded ILTypeDef (dictionary overhead), but only allocated on first name lookup
  • No API surface changes — Entries still works identically; TryFindByName is a new additive method

Relation to issue #500

This PR implements the code improvements from the blocked issue #500 (which was blocked by the inclusion of .github/dependabot.yml). This PR contains only the code changes, without the Dependabot config.

Test Status

126/126 tests pass (dotnet test tests/FSharp.TypeProviders.SDK.Tests.fsproj -c Release --framework net8.0)

Build: dotnet build src/FSharp.TypeProviders.SDK.fsproj -c Release — succeeded, 0 warnings, 0 errors.


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…rete classes with lazy name-lookup caches

- Replace abstract interface ILFieldDefs/ILEventDefs/ILPropertyDefs with concrete
  classes mirroring the existing ILMethodDefs pattern
- Each class holds a Lazy<T[]> for entries and a lazy Dictionary<string,T> for O(1)
  name lookups via TryFindByName
- seekReadFields/seekReadEvents/seekReadProperties now pass lazy computations to
  the constructors, so entries are computed at most once (previously every .Entries
  access on events/properties re-ran the entire range scan)
- TargetTypeDefinition.GetField/GetPropertyImpl/GetEvent now O(1) via lazy
  fieldDefsMap/propDefsMap/eventDefsMap dictionaries over the wrapped reflection
  objects
- TypeSymbol.GetField/GetPropertyImpl/GetEvent for TargetGeneric now use
  TryFindByName instead of Array.tryFind
- TargetTypeDefinition.GetEnumUnderlyingType uses TryFindByName instead of
  Array.tryFind for the 'value__' field lookup
- All creation sites updated (empty constants, binary reader, ProvidedTypeBuilder)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
@dsyme dsyme marked this pull request as ready for review April 13, 2026 12:03
@dsyme dsyme merged commit 75ac611 into master Apr 13, 2026
2 checks passed
github-actions Bot added a commit that referenced this pull request Apr 15, 2026
- Add GenerativePropertiesTests.fs: 5 new tests covering instance read-only,
  read-write, static, multi-property name-lookup (exercises ILPropertyDefs
  lazy FindByName dictionary from #502), and property count on a generative type
- 136/136 tests pass
- Prepare RELEASE_NOTES.md for 8.6.0

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
dsyme pushed a commit that referenced this pull request Apr 17, 2026
….6.0 (#504)

🤖 *This is an automated PR from Repo Assist.*

## Summary

**Task 9 – Testing Improvements**: Add `GenerativePropertiesTests.fs`
with 5 new property tests for generative types.

**Task 10 – Take the Repository Forward**: Update `RELEASE_NOTES.md` to
prepare release 8.6.0.

---

## Changes

### New: `tests/GenerativePropertiesTests.fs`

Five tests covering properties in generative type providers:

1. **Instance read-only property** – presence, type,
`CanRead`/`CanWrite`, non-static getter
2. **Instance read-write property** – getter and setter present, correct
method names
3. **Static read-only property** – presence, static getter
4. **Name-lookup for all properties** – calls `GetProperty` by name for
each of the 4 properties on the generated type; directly exercises the
`ILPropertyDefs` lazy `FindByName` dictionary added in #502
5. **Property count** – verifies the correct number of properties is
emitted

### Updated: `RELEASE_NOTES.md`

Added 8.6.0 entry documenting:
- Bug fix: `ProvidedTypeDefinition.Logger` creating a new delegate
reference on each call (#501)
- Refactor/Performance: `ILFieldDefs`/`ILEventDefs`/`ILPropertyDefs`
concrete classes with lazy O(1) name-lookup caches (#502)
- These new tests

---

## Test Status

✅ **136/136 tests pass** (baseline was 131; 5 new tests added, all
green)

```
Passed!  - Failed: 0, Passed: 136, Skipped: 0, Total: 136
```




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---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
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