Log of changes on okmij.org

July 1, 2025

Delimited Dynamic Binding: reworked and updated, including the implementation in terms of algebraic effects and other latest developments
(Delimited) Dynamically scoped variables in OCaml, now using effects. The implementation supports mutation of dynamic variables (which is naturally scope limited) and capturing of the dynamic environment. Applications include shared and thread-private mutable dynamic variables, and implementing lexical binding in terms of dynamic binding.
Thirty years of maintaining this web site: A bit of history

Compilers: Incrementally and Extensibly: updated course notes (as of the end of the Fall-Winter semester). The notes now include a section on types.

Module Extensibility and Separate Compilation In OCaml, linking with alternative/improved implementations, and the non-destructive library extension/evolution are problematic in separate compilation. Work-arounds are found.

do-while loops have always been in OCaml: representing do-while loops idiomatically, with no extra booleans of branching

More appreciation for a for-loop: an explanation of J.N. Oliveira's approach for transforming systems of non-tail primitive recursive equations over natural numbers to an efficient, imperative for-loop

Complete Stream Fusion for Software-Defined Radio: Strymonas-generated code is fast enough for real-time FM Radio reception, even on Raspberry Pi Zero.
MetaOCaml: Ten Years Later. The new staging translation, and, finally, some explanations of the implementation of let-insertion and cross-stage persistence
Down with power: a realistic starting example of staging, illustrating code templates (brackets/escapes), let-insertion, offshoring, real-time specialization with a flavor of JIT, and even multiple-stages
Towards a Theory of Anaphoric Binding in Event Semantics. Pronouns and in general anaphora are hardly ever analyzed in event semantics. This paper takes a stab (published in LNCS)
Simplifying the optimization framework in Modular, composable, typed optimizations in the tagless-final style to avoid GADTs. Therefore, it can be re-implemented in the languages (such as SML, etc.) that do not have GADTs.
Programming Language Support for Emerging Memory Technologies: Shonan Seminar 181
The preface (PDF) to APLAS24 Proceedings

From poly-variadic combinator to poly-variadic schema: specializing, and optimizing the poly-variadic fix-point combinator to the statically known number of functions to mutually fixpoint (in the typed and strict setting).

Teaching Compilers: Incrementally and Extensibly once more. The course notes are updated and extended.

Slide-Effect: Slide overlays and delimited control. Overlay expansion (like in Beamer) is a manifestation of delimited control. We explain on two implementations, without delimited control operators and with, showing where and how the explicit delimited control improves.

Fast and vectorizable atan: just as precise and portable as GNU Radio's, but notably faster

Boyer-Moore majority voting as map-reduce: finding the majority element in linear time, small constant space, and embarrassingly in parallel