paper

Categorical Data Structures for Technical Computing — Evan Patterson, Owen Lynch & James Fairbanks (2021; Compositionality 4 (2022)). arXiv:2106.04703 (v5, PDF).

Introduces attributed C-sets (acsets), the data structure underlying Catlab.jl: C-sets extended with attributes of fixed type. Shows acsets form a slice category of C-sets, so that limits, colimits, homomorphism search and data migration are available generically, and describes an efficient implementation in Julia with typed, schema-generated code.

Sources: the paper, arXiv:2106.04703v5, checked against the arXiv listing. Index: Papers.

Key definitions and results

  • Definitions 1–4: C-sets, free categories, finitely presented categories
  • Proposition 1: (co)limits in functor categories are pointwise
  • Definitions 5–7: schema, acset (main and alternative definitions)
  • Theorem 2: acsets on a schema form a slice category
  • Propositions 3, 5, Corollary 6: colimits and limits of acsets
  • Definitions 8–9: cospans and structured cospans of acsets

Concept notes

Attributed C-Set, Algebraic Database

Used in Sophia

Graph Schema