v0.8.0

Enhancements

• "auto" and "auto-hq" presets now default to parallel="auto"
• HyperOptimizer: now defaults to using subtree reconfiguration (turned off if any other refinement options are explitly given)
• ContractionTree.subtree_reconfigure: add maxiter="auto" option, which defaults to min(tree.N, maxiter_auto_cap), where maxiter_auto_cap is a new argument to the preset constructors (default 128 for auto and 1024 for auto-hq).
• Added a benchmarking example - Benchmarking and cotengra
• Default node type for ContractionTree changed to SSA-based representation, which is faster and uses less memory for big trees. Factored out node logic into a new nodeops module, with dynamic namespaces supporting both frozenset-based and SSA-based nodes.
• ContractionTree: add get_peak_size, reorder_for_peak_size, and max_contraction_size.
• ContractionTree: support single input "contractions" (trivial trees with a single tensor).
• HyperOptimizer.search: support single terms (#77).
• Change default finishing optimize step (e.g. for slicing/subtree reconfigure) to "auto".
• Subtree reconfigure: add select="descend" mode.
• PartitionTreeBuilder.build_divide: default to random-greedy-128 for super_optimize.
• Greedy optimizers: add max_neighbors option to limit candidate pair generation, which helps for graphs with very large batch indices.
• Allow hashing optimize when given as a list of lists (e.g. nested SSA paths).
• Refactor the optlib interface for cleaner integration of multiple Bayesian / population-based optimizers; add sbplx, sses (steady-state evolutionary strategy), and neldermead / neldermead-adapt simple internal optimizers.
• Add implementation="pytblis" for contraction via pytblis.
• Update parallel logic for sub-workers, allowing nested parallelism without oversubscription.
• DiskDict: add get, keys, values, items, __delitem__; enhance clear and cleanup methods.
• Python optimal optimizer: accept float factors (#58).
• Update schematic module with improvements pulled in from quimb.
• einsum via bmm (implementation="cotengra"): update einsum-string parsing to follow more recent numpy behavior.

Bug fixes

• Fix a rare bug relating to wrongly cached index ordering in ContractionTree.
• Fix + test tensorflow contraction with strip_exponent (#81).
• ContractionTree.contract_nodes: always check for root, fixing an edge case in incremental contraction.

Infrastructure

• Move CI and developer workflow to Pixi (per-environment jobs, formatting tasks, readthedocs config). Add torch/jax/tensorflow test jobs. Various dependabot bumps.