ILNumerics.Community.Analyzers 7.2.0.18

Analyzers

A set of Roslyn analyzers and code fixes to enforce ILNumerics (http://ilnumerics.net/) function & memory rules (see https://ilnumerics.net/FunctionRules.html).

ILNumerics function rules ensure that APIs using ILNumerics arrays clearly separate inputs, outputs, and locals, and that signatures communicate this intent explicitly. Inputs are passed as InArray<T>, outputs as OutArray<T>, and return values as RetArray<T>. Regular Array<T> is reserved for local (or class level) variables. This avoids accidental reuse of result buffers, prevents hidden allocations, and makes data flow and lifetime of ILNumerics arrays obvious and analyzable.

Getting started

Install the NuGet package ILNumerics.Community.Analyzers into any project that should be analyzed:

dotnet add package ILNumerics.Community.Analyzers

• The package contains both analyzers and code fixes.
• Visual Studio and other supported IDEs will run them during typing (live analysis) and on build.

Rules

• ILN0001 — Don't use var for (local) ILNumerics arrays

  Implicit typing is forbidden for ILNumerics arrays (Array<T>, InArray<T>, OutArray<T>, RetArray<T>, Logical, Cell, etc.). Use explicit types so readers (and the analyzer) can see whether a variable is an input, output, return buffer, or local Array<T>. This prevents subtle bugs where a RetArray<T> is reused in unexpected ways.

• ILN0002 — Only In/Out/Ret in signatures (not in bodies/fields/props)

  InArray<T>, OutArray<T>, and RetArray<T> are meant purely as API "flavors" for parameters and return types. They must not appear as locals, fields, or general properties. Exceptions are very constrained: get‑only Ret* properties, set‑only or init‑only In* properties are allowed as configuration‑style surfaces, but all other uses in the object model or locals are flagged.

• ILN0003 — Function signatures should use ILNumerics flavors (in/out parameter and returns)

  Public/internal methods that expose ILNumerics arrays should not use plain Array<T> in signatures. Parameters should be InArray<T>/OutArray<T> and return values should be RetArray<T>. This documents the function contract (who owns the buffer, who may modify it) and enables the runtime and analyzers to enforce correct reuse and memory behavior.

• ILN0004 — Avoid C# out/ref with ILNumerics arrays (use OutArray<T>)

  ILNumerics discourages C# ref/out parameters for its array types. Instead of ref Array<T> or out Array<T>, APIs should use OutArray<T> (or the appropriate flavor) and pass arrays in the ILNumerics way. This keeps ownership and reuse semantics consistent and avoids clashes between C# reference semantics and ILNumerics' buffer management model.

• ILN0005 — ILNumerics fields should use localMember<T>() and safe assignment

  Instance fields of ILNumerics Array<T> types are treated as local members: they should be initialized via localMember<T>(). ILN0005 flags non‑static Array<T> fields that either have no initializer or use something other than localMember<T>(). Valid writes to fields must use either _A.a = ... or _A.Assign(...), which keeps the field buffer stable following expected lifetime conventions.

• ILN0006 — Use GetValue()/SetValue() for scalar element access

  Scalar reads from ILNumerics Array<T> should use GetValue(...) rather than indexer access combined with an explicit cast (for example: (T) A[i, j]). ILN0006 reports cases where an element access is cast to the array's element type, and the code fix rewrites it to A.GetValue(i, j) to make scalar access explicit and consistent.

Troubleshooting

No squiggles but lightbulb available: enable live analysis in the IDE (VS: Tools → Options → Text Editor → C# → Advanced → Enable .NET analyzers, Full solution analysis) and ensure .editorconfig does not suppress diagnostics.

Contributing

Contributions, bug reports and feature requests are welcome. Please open an issue or a pull request on the GitHub repository.

License

ILNumerics.Community.Analyzers is licensed under the terms of the MIT license (http://opensource.org/licenses/MIT, see LICENSE.txt).