المفاهيم الأساسية
The author presents an algebraic representation for edge graphs based on total and recursive definitions, aiming to prevent usage errors and promote structurally recursive computations.
الملخص
Edge graphs are complex structures used to model various systems. The author introduces a novel data type for edge graphs, emphasizing total and recursive definitions to prevent usage errors. The algebraic approach provides primitive constructors and combinators, ensuring semantically equivalent constructions. Common graph algorithms can be implemented using homomorphisms within this framework.
The content delves into the challenges of representing edge graphs effectively in functional programs due to their unique structure. Various existing representations like adjacency lists are critiqued for inefficiencies and partial functions. The paper proposes an algebraic data type approach with total and recursive definitions to address these limitations. By defining a set of constructors and equational laws, the author aims to formalize properties such as soundness and completeness while minimizing usage errors.
The literature review highlights previous attempts at characterizing graphs with algebras, showcasing the development of directed acyclic multigraph algebra by Gibbons. Mokhov's work on node graph algebra is also discussed, leading to the introduction of an elegant algebra for graphs with semiring edge labels. The paper concludes by outlining future directions for implementing graph algorithms within the proposed edge graph algebra framework.
Key points include the definition of flow representations for edge graphs, the construction of various types of edge graphs using operators like overlay, into, pits, and tips, and the establishment of axioms to ensure coherence in the algebraic structure.
الإحصائيات
Erwig provides an alternative using inductive graphs where inserting a node takes O(nlog n) time.
Mokhov introduced an elegant algebra for node graphs that supports rich Haskell libraries.
The adjacency lists representation does not enforce consistency in edge identifiers.
The deep embedding allows compact representation but may not be efficient for complex edge graphs.
اقتباسات
"Either their interface is riddled with partial functions or the representations are computationally inefficient."
"In giving a theoretical grounding for the edge graph data type, we can formalize properties such as soundness and completeness."
"The lack of partiality prevents usage errors from invalid inputs."