arXiv subjects

Alex Hubers

Publications and source records attributed to Alex Hubers.

3 recordsLinked to original sources

arXiv2024

Abstracting Extensible Recursive Functions

We explore recursive programming with extensible data types. Row types make the structure of data types first class, and can express a variety of type system features including record subtyping and combination of case branches. Our goal is the modular combination of recursive types and of recursive functions over them. The most significant challenge is in recursive function calls, which may need to account for new cases in a combined type. We introduce extensible histomorphisms, Mendler-style descriptions of recursive functions in which recursive calls can happen at larger types, and show that they provide expressive recursion over extensible data types. We formalize our approach in R$\omega\mu$, a row type theory with support for recursive terms and types.

cs.PL↗

arXiv2023

Generic Programming with Extensible Data Types; Or, Making Ad Hoc Extensible Data Types Less Ad Hoc

We present a novel approach to generic programming over extensible data types. Row types capture the structure of records and variants, and can be used to express record and variant subtyping, record extension, and modular composition of case branches. We extend row typing to capture generic programming over rows themselves, capturing patterns including lifting operations to records and variations from their component types, and the duality between cases blocks over variants and records of labeled functions, without placing specific requirements on the fields or constructors present in the records and variants. We formalize our approach in System R{\omega}, an extension of F{\omega} with row types, and give a denotational semantics for (stratified) R{\omega} in Agda.

cs.PL↗

arXiv2016

Sketched Floor plans versus SLAM maps: A Comparison

Maps --- specifically floor plans --- are useful for a variety of tasks from arranging furniture to designating conceptual or functional spaces (e.g., kitchen, walkway). We present a simple algorithm for quickly laying a floor plan (or other conceptual map) onto a SLAM map, creating a one-to-one mapping between them. Our goal was to enable using a floor plan (or other hand-drawn or annotated map) in robotic applications instead of the typical SLAM map created by the robot. We look at two use cases, specifying "no-go" regions within a room and locating objects within a scanned room. Although a user study showed no statistical difference between the two types of maps in terms of performance on this spatial memory task, we argue that floor plans are closer to the mental maps people would naturally draw to characterize spaces.

cs.HC↗