Legacy removal checklist (for linopy 1.0)

Legacy removal checklist (for linopy 1.0)#

The v1 convention ships alongside legacy from 0.x onward and replaces it entirely at 1.0. This file enumerates everything to delete when that release happens, in dependency order. Most edits are mechanical; grep "LEGACY: remove at 1.0" finds every inline marker comment in the source tree.

Implementation#

linopy/config.py#

  • Drop LEGACY_SEMANTICS, V1_SEMANTICS, VALID_SEMANTICS constants.

  • Drop the LinopySemanticsWarning class.

  • Remove the semantics key from options. The option no longer exists; callers don’t need to opt in.

  • Remove the v1/legacy validation branch in set_value.

linopy/semantics.py#

  • Delete is_v1() (always true). Inline True at the four import sites in expressions.py/variables.py or, better, delete the import and the now-dead else branches alongside it.

  • Drop the legacy-warn branch from check_user_nan / check_user_nan_breakpoints — both become a single raise ValueError(...).

  • enforce_merge_dims: drop its two warn_legacy branches; the v1 raise on a mismatch or reorder is all that is left.

  • Delete every _legacy_*_message helper and warn_legacy itself.

  • shared_dim_mismatches, conflicting_aux_coord, absorb_absence stay — they’re v1 enforcement helpers.

linopy/expressions.py#

  • _add_constant: delete _add_constant_legacy; inline _add_constant_v1 into the now-trivial dispatcher (or rename it to _add_constant).

  • _apply_constant_op: same treatment with _apply_constant_op_legacy.

  • _align_constant: delete the else branch under if join is None: that handles the legacy size-aware default (other.sizes == self.const.sizes positional + reindex_like left-join paths). The explicit-join code below stays, as do the _broadcast_and_align / _reindexed_to helpers.

  • to_constraint: keep the if is_v1(): body and delete the else branch (the legacy auto-mask: the rhs_nan_mask plumbing plus the rhs.reindex_like(..., fill_value=np.nan) pad).

  • LinearExpression.isnull: drop the legacy (self.vars == -1).all(...) & self.const.isnull() branch — self.const.isnull() is the v1 answer.

  • merge:

    • The §8 / §11 legacy warns live in enforce_merge_dims / enforce_aux_conflict; both calls stay, only their legacy branches go.

    • The skipna = not is_v1() simplifies to skipna = False (v1’s propagation rule).

    • The trailing if is_v1(): ds = absorb_absence(ds) becomes unconditional.

  • Drop the legacy warn_legacy message imports from expressions.py.

linopy/variables.py#

  • Variable.to_linexpr: drop the else branch (legacy reindex_like(fill_value=0).fillna(0)); make the v1 reindex_like( fill_value=NaN) → .where(~absent) path unconditional. The const = NaN/0 assign also becomes unconditional.

  • Drop the from linopy.semantics import is_v1 import.

linopy/alignment.py#

  • _enforce_implicit_projections: drop the legacy warn_legacy(...) branch — the v1 raise for partial-level / coverage-gap projections becomes unconditional. The projection machinery itself (_project_onto_multiindex_levels, _LevelProjection) stays: full-coverage full-level projections remain legal under v1 (they are the same coordinate spelled differently, §8).

  • _dims_for_unlabeled_operand: drop the legacy positional-pairing fallback (the warn_legacy(...) branches plus return positional); the v1 size-pairing — the is_v1() block that raises on ambiguity / no-match — becomes the whole function. The as_constant / _pair_axes_by_size helpers stay (v1-clean).

linopy/piecewise.py / linopy/sos_reformulation.py#

Nothing to remove; these are v1-clean (the drop=True / assign_coords fixes from Slice P are correct for both semantics).

Tests#

test/conftest.py#

  • Drop the LEGACY_SEMANTICS/V1_SEMANTICS/VALID_SEMANTICS imports and the LinopySemanticsWarning import.

  • Drop the legacy / v1 marker registration in pytest_configure.

  • Delete the autouse semantics fixture entirely (no more parameterization, no more warning suppression).

test/test_legacy_violations.py#

  • Delete the file. Everything in it either documents legacy behaviour (gone) or tests v1 raises (covered by the per-module test files we add tests to alongside the implementation).

    Before deleting, move any v1 tests that don’t have a per-§ home into the appropriate module:

    • TestExactAlignmentConstant, TestExactAlignmentMerge, TestBroadcastNonSharedDim → test_linear_expression.py.

    • TestConstraintRHS → test_constraints.py.

    • The rest are small enough to fold in alongside related tests.

test/test_convention.py#

  • Delete the file (it tests the options["semantics"] framework, which is gone).

Marker stripping#

grep -rn "@pytest.mark.legacy\|@pytest.mark.v1\|pytestmark = pytest.mark.legacy" test/ finds every marker:

  • @pytest.mark.legacy decorators — delete the decorator (the test body is documenting old behaviour; deleting the whole test is usually right). Spot-check before each delete; a few “legacy” marks turned out to gate on legacy auto-mask semantics and the test itself stays valid under v1.

  • @pytest.mark.v1 decorators — strip the decorator (the test stays).

  • pytestmark = pytest.mark.legacy at module level — was only used while piecewise.py was non-v1-aware; removed in Slice P. Verify none remain.

Documentation#

doc/design/goals.rst#

  • Drop the entire “Transitioning goals” section (the three transitioning goals + the schedule are about the legacy bridge, which is gone).

  • Goal #4’s mention of LinopySemanticsWarning (if any) goes.

doc/design/convention.rst#

  • Drop the ## Legacy framing if it exists. Each § already describes v1 directly; any “where today this does X” asides referencing legacy behaviour can go.

  • Update the intro: “The strict (‘v1’) convention” → “The arithmetic convention” (drops the v1 framing now that there’s only one).

This file (doc/design/legacy-removal.rst)#

  • Delete after the 1.0 release ships.

Order of operations#

A safe sequence (each step compiles and tests pass):

  1. Delete legacy test infrastructure (test/conftest.py fixture, test/test_convention.py, test/test_legacy_violations.py after moving v1 tests out).

  2. Strip @pytest.mark.legacy decorators (the tests fail under v1 anyway once the legacy paths are gone — delete or update each).

  3. Delete legacy implementation branches in expressions.py / variables.py.

  4. Delete semantics.py legacy bits (is_v1, warn_legacy, the _legacy_*_message helpers and the warn branches that call them).

  5. Delete config.py symbols (LEGACY_SEMANTICS, the warning class, the option key).

  6. Update doc/design/goals.rst and doc/design/convention.rst.

  7. Delete this file.