| CS-2026-01 | ||||
|---|---|---|---|---|
| Title | Curvature Continuous Piecewise Pythagorean Hodograph Curves | |||
| Author | Stephen Mann | |||
| Abstract | This report develops constructions for cubic, quartic, and quintic Pythagorean hodograph curves (PHC). The cubic construction is a rederivation of an earlier cubic PHC construction, but in the real plane rather than the imaginary plane. The quartic construction is also a rederivation of an earlier construction, again in the real plane rather than the imaginary plane. In addition, the free parameter in this quartic construction is used to interpolate curvature at one end of the curve. The quintic construction builds a quintic PHC curve that interpolates the position, tangent, and curvature at two points. | |||
| Date | February 3, 2026 | |||
| Report | CS-2026-01 (760 kB PDF) | |||
| CS-2026-02 | ||||
| Title | Virtualizing Continuations (Extended Version) | |||
| Authors | Cong Ma, Jonghyun Jung, Yizhou Zhang | |||
| Abstract | Effect handlers and multishot continuations are powerful abstractions for managing control flow; together, they offer concise and modular ways to express and handle nondeterminism, randomness, and more. However, implementing multishot continuations in the presence of stack-allocated lexical resources—lexical effect handlers in particular—is challenging, since stack copying invalidates references to these resources. We present a novel implementation strategy for lexical effect handlers that fully supports multishot continuations. The key idea is to virtualize the stack space used by continuations. Each stack-allocated handler instance is assigned a virtual address, and all effect invocations through these virtual addresses are mediated by an address translation mechanism. A software-based memory management unit in the runtime system performs these translations efficiently, exploiting the lexical scoping discipline of effect handlers. We capture the essence of our approach via a new operational semantics for lexical effect handlers and prove it correct with respect to the standard semantics. We also implement it in a compiler and runtime system. Compared to prior languages with lexical effect handlers, our implementation increases expressivity by fully supporting multishot continuations—and, as a happy consequence, unlocks significant performance gains by enabling parallel execution of multishot continuations. |
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| Date | May 20, 2026 | |||
| Report | CS-2026-02 (492 kB PDF) | |||