DRYML

DRYML provides immutable construction definitions, exact graph references, and local checkpoint publication for Python machine-learning objects.

Composable Object State

Definition authors an immutable Node graph. Concretizing it produces a ConcreteNode: normalized construction structure, independently of saved-state completeness. Each node can select an ObjectId and a compatible local StateKey independently. recipe.bind(identities=..., states=...) composes constraints; contradictory assignments through aliases fail rather than silently overriding.

Node handle equality identifies an occurrence/view; use graph_equal for exact graph semantics and object_projection_equal for state-independent realized identity. SavedNode is the complete-saved typing refinement of the same graph, validated by require_saved, not another graph model. Metadata inspection does not construct Objects or read private state. Concrete .args/.kwargs call projections may resolve the current class; use .cls/.parameters for inspection.

from pathlib import Path
from dryml import Repo, Serializable
from dryml.core.store.dir import DirStore


class Counter(Serializable):
    """Persist one mutable integer independently of its construction recipe."""

    def __init__(self, value=0):
        super().__init__()
        self.value = value

    def save_state_to_dir_imp(self, dest_dir, *, codec):
        """Write the current value to the framework-owned private data directory."""
        Path(dest_dir, "value").write_text(str(self.value), encoding="ascii")

    def restore_state_from_dir_imp(self, src_dir, *, codec):
        """Restore a previously authenticated value; invalid integer data raises."""
        self.value = int(Path(src_dir, "value").read_text(encoding="ascii"))


repo = Repo(DirStore("./checkpoint-store"))
counter = Counter(3, repo=repo)
counter.value = 5
state = counter.save(repo=repo)
restored = repo.load_state_ref(state, reuse_live="never")
assert restored.value == 5
assert restored.object_id == counter.object_id
assert repo.describe(restored).object_projection_equal(state)

Object.save() publishes a retained SavedNode through connected durable Stores. Each distinct live stateful node needing fresh state is captured once; explicit states= reuse avoids recapturing selected bytes. A last-save receipt does not prove unchanged mutable state. Store 4 uses CDef-owned state buckets and full StateKeys; old Stores are rejected intact, without automatic migration.

Managed methods return InvocationResult, with lazy .value, detached .status/.execution, and .final_state_ref. Compatible completed calls replay without running, restoring or saving the receiver. Explicit rerun controls start selection; missing selected state never silently initializes or falls back.

See Objects and Definitions, Repos and Stores, Formats, and Graph Querying. See Managed Operations and the verification record for retention, recovery, measured work and integrated verification results.