Errata

This book claims that its samples cannot rot: every program, transcript, and diagnostic on these pages was executed by CI against the toolchain in the colophon, and a sample that stops behaving fails the build. That covers the code. It does not cover the prose, the arithmetic in a paragraph, or a claim that was true when it was written and is false now, so this page exists and so does the process behind it.

Report anything wrong at https://github.com/wolffe-lang/wolf-book/issues. Three kinds of report are useful, and the issue template asks which one you have:

Technical. A sample that is wrong, a claim that is false, a diagnostic that no longer says what the page says it says, a comparison to another language that its own users would object to. These go through the reviewer checklist before the fix lands: the claim gets traced to a spec clause or a decision, and the sample gets executed. Include the toolchain version from wolf --version and lupin --version, because the first question is always whether your pin is the colophon’s.

Editorial. Typos, broken sentences, a term used two ways, a cross-reference pointing at the wrong section, a heading that lies about its section. These take the fast path and land as soon as they are read.

Drift. A sample that no longer runs on a newer toolchain than the colophon’s. CI catches most of this before a reader does — the book builds against the compiler’s own main branch nightly, and a break is visible there first — but the nightly is a report and not a gate, so a reader on a newer toolchain may arrive first. Drift is fixed at the next pin bump, together, deliberately.

What this edition promises

The web edition tracks one toolchain at a time and says which one in the colophon. When the pin moves, every sample is re-executed, every diagnostic is re-captured, and the changes are listed in the repository’s history with the bump. A printed copy is a photograph of one such moment: corrections to print are made at reprint, and until then they are listed here, so a reader holding paper and a reader holding a browser are reading the same book with one of them carrying a footnote.

Fixes are not silent. A technical correction changes the page and says so in the commit that carries it; an editorial one changes the page. Neither is backdated, and no claim in this book is quietly withdrawn.

Known corrections

None yet in this edition.