feature-matrix.md

title	Language Feature Matrix
audience	users, developers
prerequisites	user guide
related	../guide/index.md, ../reference/fortran-wrapper.md
status	maintained
publication	draft

Language Feature Matrix

This matrix is the user-facing support index for native-language features. It does not replace the detailed Fortran wrapper reference; it points each feature to the owning docs, implementation route, evidence, and limitations.

A row may claim support only when the linked evidence proves that behavior in the current repository. Runtime wrapper support requires compiled, imported, and called wrapper tests. Parser or semantic support alone is listed as inspection-only or partial support.

Status Meanings

Status	Meaning
Supported	The documented subset has current runtime or inspection evidence.
Partially supported	A useful subset is implemented and tested, but important related forms are blocked or deferred.
Unsupported	prik intentionally blocks the form or has no safe wrapper contract for it yet.
Planned	The feature has a reserved documentation or roadmap entry but no support claim.
Not implemented	The feature is explicitly outside the current implemented surface.

Supported Runtime Features

Feature	Status	User docs	Source owner	Evidence	Limitations
Scalar functions, subroutines, and baseline arrays	Supported	Functions, subroutines	Wrapper pipeline	Verified baseline tests	Native scalar arguments require exact NumPy dtypes where documented.
Generic procedure interfaces	Supported	Generic interfaces	Feature route	Generic interface tests	Defined operators and assignment are tracked separately.
Defined operators and assignment overloads	Supported	Defined operators	Bridge and binding generation	Defined operator tests	Supported operators are those covered by the wrapper guide and runtime tests.
Output arguments and multiple results	Supported	Subroutine projection	Ownership and lowering	Calls and results tests, function result tests	Tuple ordering and caller-provided array behavior follow the wrapper guide.
Optional arguments	Supported	Optional arguments	Binding generation	Optional argument tests	Unsupported optional combinations fail during wrapper planning.
Allocatable array handles, descriptor arguments, and owned results	Supported	Allocatables	Ownership policy	Allocatable runtime tests, scalar-derived matrix tests	Array module/field handles borrow their owner; result handles own persistent descriptor storage. Wrapper-owned scalar-derived allocatables use typed holders; module scalar allocatables use reversible move_alloc transactions for compatible dummies.
Pointer scalar projections and array handles	Partially supported	Pointers	Ownership policy	Pointer handle tests, pointer policy tests, scalar-derived matrix tests	Descriptor arguments, module/field handles, strided views, wrapper-owned pointer-array results and outputs, scalar-derived pointer holders, and module pointer reassociation transactions are supported. Target deallocation and writable reassociation remain policy-gated.
Array-valued function results	Supported	Array results	Array lowering	Array result tests	Ownership and dtype/shape behavior are limited to documented array result forms.
NumPy array argument contracts	Supported	Arrays	Bridge and binding generation	Array contract tests, multidimensional tests	Wrong dtype, rank, shape, contiguity, alignment, or mutability is rejected.
Derived-type scalar boundaries and methods	Supported	Derived types	Class lowering	Derived boundary tests, method tests	Derived-type arrays and some polymorphic forms are not included.
Default and keyword constructors with finalizers	Supported	Constructors and finalizers	Ownership policy	Constructor/finalizer tests, borrowed finalizer tests	Construction commits ownership only after initialization; borrowed wrappers never run an owning finalizer.
Generic constructor interfaces and overloaded runtime initialization	Supported	Constructors	Class policy and lowering	Edited class surface tests, class policy tests	Candidates require distinguishable completed Python signatures; incomplete or ambiguous sets are blocked before emission.
Module variables, constants, saved state, and common-block procedure state	Supported	Wrapping modules	Module state route	Module state tests, scalar-derived matrix tests, common-block tests	Common-block storage is not exported as Python variables. Rank-zero derived module objects use direct, scoped, allocation-transaction, or pointer-transaction handoff selected before lowering.
Fortran enum constants	Supported	Enumerations	Semantic constants route	Enum runtime tests, enum semantic tests, enum diagnostics	No Python Enum or IntEnum classes are generated.
Scalar character arguments, results, and fields	Supported	Strings	Character bridge route	Character argument tests, edge-case tests	Character arrays use fixed-width NumPy bytes dtype; mutable scalar deferred-length storage is blocked.
Scalar kind coverage	Supported	Data types	Fortran type probe	Scalar kind tests	Wider real, complex, and explicit logical storage is blocked without portable NumPy mapping.
Caller-ordered multi-source builds, Makefiles, verbose mode, and output placement	Supported	Building the shared library	Wrapper orchestration	Multi-source tests, compiler verbose tests	prik does not discover, reorder, or resolve all external source dependencies.
Visibility, naming, keyword escaping, and collision policy	Supported	Visibility and naming	Naming policy	Visibility/naming tests	Strict mode rejects names that default mode can normalize.
Immediate call-scoped Python callbacks	Supported	Callbacks	Callback bridge route	Callback plan tests, scalar callback tests, array callback tests, combined shape tests	Direct wrapper-plan generation supports entering-thread callbacks only. Stored, optional, asynchronous, or cross-thread callbacks are unsupported.
Runtime error projection, GIL policy, recursion, OpenMP path, and GNU ABI checks	Supported	Error handling	Runtime route	Status projection runtime, status and GIL lowering, recursion tests, OpenMP tests, ABI tests	OpenMP and ABI evidence is compiler/platform-specific; callers still own native synchronization.
Fortran source wrapper builds	Supported	Building the shared library	Wrapper orchestration	Build modes, runtime ABI	Implemented for ordered Fortran source inputs.

Supported Inspection Features

Feature	Status	User docs	Source owner	Evidence	Limitations
Fortran parse, semantic IR, and .pyi inspection	Supported	Fortran inspection recipe, semantic IR	Fortran parser route	Fortran parser fixtures, Fortran semantic tests	Inspection support does not by itself prove runtime wrapper support.
Semantic .pyi wrapper builds from explicit native artifacts	Partially supported	Semantic .pyi contracts, .pyi format	.pyi build route	format and authoritative-input tests, multi-source contract tests, native build plan tests	Current runtime parity is limited; source/generated/modified multi-source package parity is covered, and broader parity remains tracked in the checklist.
Scalar inheritance and polymorphic dispatch	Partially supported	Inheritance and polymorphism	Class lowering route	Inheritance tests	Polymorphic results, mutable dummies, arrays, allocatable/pointer scalars, and class(*) are blocked.
Assumed-size, assumed-rank, and lower-bound array contracts	Partially supported	Arrays	Array bridge route	Assumed-rank tests	Assumed type and derived-type arrays remain blocked. Character arrays require fixed-width NumPy bytes dtype.
Generated reference pages for modules, functions, and classes	Partially supported	Reference index	Source map	Documentation structure checks, semantic contract tests	Maintained manual references exist for generated functions, modules, classes, and generated file contracts; automated reference inventory generation has not been selected.

Unsupported Or Blocked Forms

Feature	Status	User docs	Source owner	Evidence	Limitations
Unproved pointer lifetime and ownership-changing operations	Unsupported	Pointer safety	Ownership policy	Pointer policy tests, pointer runtime tests	Native targets must outlive every handle use; allocation, target deallocation, resize, and writable reassociation require explicit completed policy.
Persistent callbacks and procedure pointers	Unsupported	Callback limitations	Callback route	Callback policy tests, scalar callback tests	Callbacks are valid only during the wrapped call.
Advanced multi-source dependency discovery and external-library integration	Unsupported	Multiple source files	Build orchestration	Multi-source tests	prik does not infer dependency graphs, prebuilt module paths, or external library discovery.
Blocked array forms	Unsupported	Unsupported array forms	Array policy route	Array semantic tests, diagnostics	Assumed type type(*), arrays of derived types, and character arrays not representable as fixed-width bytes need missing runtime contracts.
Unsupported polymorphic forms	Unsupported	Inheritance limits	Class policy route	Inheritance tests	Results, mutable dummies, arrays, polymorphic allocatable/pointer scalars, and class(*) are blocked.
Ambiguous or incomplete constructor overload sets	Unsupported	Constructor limitations	Constructor route	Constructor semantic tests, class-plan validation tests	Candidates must have distinguishable exact runtime signatures and compatible native-owner lifecycles.
Character arrays and mutable deferred-length character storage	Partially supported	Strings	Character bridge route	Character edge tests	Character arrays use fixed-width NumPy bytes dtype. Fixed and allocatable deferred element length maps to dtype itemsize; Unicode/object arrays and mutable scalar deferred-length storage are unsupported.
Wider-than-supported real, complex, and logical storage	Unsupported	Datatype limits	Type probing	Scalar kind tests	prik blocks rather than silently losing precision or Boolean storage semantics.

Planned Or Reserved Areas

Feature	Status	User docs	Source owner	Evidence	Limitations
Full semantic .pyi parity across all wrapper scenarios	Planned	Semantic .pyi format	.pyi route	semantic .pyi feature tests	Only the documented implemented subset is supported.
MPI examples and distribution constraints	Not implemented	MPI example	Planned examples	Documentation structure checks	No support contract or runnable evidence exists yet.