April 18, 2026
Em-dashes, hot takes, and a Lisp revival
Modern Common Lisp with FSET
Docs drop, fans cheer, nitpickers pounce, and a Clojure crossover steals the show
TLDR: A new guide for FSet aims to modernize Common Lisp with fast, safe data structures. Commenters cheered the ambition, complained about the buried intro and missing one-page view, nitpicked a Scheme section, and hyped ties to a project bringing Clojure to Common Lisp—making it both useful and buzzy.
Common Lisp just got a glow-up. Scott L. Burson released a big, friendly guide to FSet, a toolkit of modern, safe-as-heck data containers that don’t mutate in place (think: copy-paste that stays fast). The guide even flexes: “no AI text — zero, zip, nada.” But the comments? They’re the real show.
The top vibe: respect mixed with side-eye. One reader went full media critic, saying the actual mission statement is “hidden 13 paragraphs down the third page.” That’s classic “burying the lede,” and the thread ate it up. Another practical voice asked for a single-page view like it was a life-or-death scrollathon. Meanwhile, the language lawyers arrived on cue: someone flagged the Scheme (a cousin of Lisp) section as “a little confused,” sparking the eternal “whose standard is standard?” debate.
Then came the crossover hype. A commenter connected FSet to Cloture — a project aiming to run Clojure (another popular Lisp) on Common Lisp — and suddenly we had a mini cinematic universe. Fans reminisced about seeing the talk at the Bay Area Lisp meetup, adding that warm “I was there” energy.
So, the mood: big upgrade energy, doc-structure gripes, a sprinkle of standards pedantry, and a surprise Clojure cameo. In short, the library is modern; the comments are timelessly spicy.
Key Points
- •The document is “Modern Common Lisp with FSet” Version 1.0, covering FSet v2.4.2, authored by Scott L. Burson.
- •It is licensed under Creative Commons CC BY-NC-SA 4.0 and states it contains no LLM-generated text.
- •Issue reporting is directed to Common-Lisp.Net’s GitLab instance and the project’s GitHub repository.
- •Content includes tutorials on sets, maps, seqs, and bags; usage guidance (importing symbols, extensions); and Emacs customizations.
- •Design and implementation topics include equality and hashing, the @ macro, quasi-mutating operators, weight-balanced and CHAMP trees, and support for user-defined classes.