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arXiv · 1808.07826

Fungi: Typed incremental computation with names

Matthew A. Hammer·Jana Dunfield·Kyle Headley·Monal Narasimhamurthy·Dimitrios J. Economou
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Abstract

Incremental computations attempt to exploit input similarities over time, reusing work that is unaffected by input changes. To maximize this reuse in a general-purpose programming setting, programmers need a mechanism to identify dynamic allocations (of data and subcomputations) that correspond over time. We present Fungi, a typed functional language for incremental computation with names. Unlike prior general-purpose languages for incremental computing, Fungi's notion of names is formal, general, and statically verifiable. Fungi's type-and-effect system permits the programmer to encode (program-specific) local invariants about names, and to use these invariants to establish global uniqueness for their composed programs, the property of using names correctly. We prove that well-typed Fungi programs respect global uniqueness. We derive a bidirectional version of the type and effect system, and we have implemented a prototype of Fungi in Rust. We apply Fungi to a library of incremental collections, showing that it is expressive in practice.

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BibTeXRIS

Matthew A. Hammer, Jana Dunfield, Kyle Headley, Monal Narasimhamurthy, Dimitrios J. Economou. 2018-08-20. Fungi: Typed incremental computation with names. https://arxiv.org/abs/1808.07826

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