refactor[next-dace]: change dispatching of visitors for builtin functions

[edopao]

The refactoring includes the following changes:

• rename gtir_to_sdfg to gtir_to_sdfg_fieldview
• rename gtir_dataflow to gtir_to_sdfg_iterator
• rename build_sdfg_from_gtir to lower_program_to_sdfg
• refactor the dispatch of visitors for builtin function, in both gtir_to_sdfg_fieldview and gtir_to_sdfg_iterator

[Copilot]

Pull request overview

This PR refactors the DaCe lowering pipeline for gt4py.next by renaming key lowering entry points and restructuring how builtin-function visitors are dispatched in both the fieldview and iterator lowering paths.

Changes:

• Renames/reshapes lowering entry points (e.g., build_sdfg_from_gtir → lower_program_to_sdfg) and adjusts imports/types accordingly.
• Refactors builtin dispatch in GTIRToSDFG (fieldview) and LambdaToDataflow (iterator) via centralized handler maps.
• Updates scan/primitives/type helpers to use the split fieldview/iterator lowering modules.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_types.py	Updates local-view helpers to return iterator-based IteratorExpr/MemletExpr types.
src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_scan.py	Switches scan lowering to the new fieldview/iterator module split and updated dataflow types.
src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_primitives.py	Retypes primitives to the split builders and iterator dataflow edges; small typing-related adjustments.
src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_iterator.py	Refactors builtin dispatch in lambda-to-dataflow and retargets builder typing to fieldview interfaces.
src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_fieldview.py	Refactors builtin dispatch in program lowering; introduces _visit_* helpers; renames program lowering entry point.
src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_concat_where.py	Updates concat_where lowering to use the fieldview lowering module split.
src/gt4py/next/program_processors/runners/dace/lowering/init.py	Updates lowering package exports to point at the refactored lowering entry points.

Comments suppressed due to low confidence (3)

src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_iterator.py:58

• gtir_to_sdfg_iterator.py imports gtir_to_sdfg_fieldview using the src.gt4py... package path, which will fail at runtime outside the repository checkout layout. Also, since this module uses from __future__ import annotations, this import is only needed for type checking and can be placed under TYPE_CHECKING to avoid creating an import cycle (fieldview -> primitives -> iterator -> fieldview).
  src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_iterator.py:18
• The new TYPE_CHECKING-guarded import for gtir_to_sdfg_fieldview (recommended below) requires TYPE_CHECKING to be imported from typing in this module.
  src/gt4py/next/program_processors/runners/dace/lowering/init.py:23
• lowering/__init__.py re-exports build_sdfg_from_gtir from gtir_to_sdfg_fieldview, but that function was renamed to lower_program_to_sdfg (and build_sdfg_from_gtir no longer exists). This currently breaks imports like gtx_dace_lowering.build_sdfg_from_gtir(...) used elsewhere in the codebase.

from gt4py.next.program_processors.runners.dace.lowering.gtir_to_sdfg_fieldview import (
    build_sdfg_from_gtir,
)
from gt4py.next.program_processors.runners.dace.lowering.gtir_to_sdfg_utils import (
    flatten_tuple_fields,
    get_map_variable,
)


__all__ = [
    "build_sdfg_from_gtir",
    "flatten_tuple_fields",
    "get_map_variable",
]

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_fieldview.py:1231

• This comment line has a stray "to." at the end (likely meant to be "symbols."), which makes the sentence ungrammatical.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/gt4py/next/program_processors/runners/dace/lowering/gtir_to_sdfg_iterator.py:52

• gtir_to_sdfg_fieldview is imported here only to satisfy type annotations, but this creates an avoidable import edge (and contributes to circular imports: fieldview -> primitives -> iterator -> fieldview). Since this module uses from __future__ import annotations, you can move the import behind typing.TYPE_CHECKING (or otherwise defer it) to keep runtime imports acyclic.