Docs follow-up for RFC 0028: untyped R functions are now callable

[fabriceHategekimana]

Context

RFC 0028 (we-data-ch/typr#28, tracking we-data-ch/typr#29) was implemented in we-data-ch/typr#30: an untyped R function (function(a, b) { ... }) is now callable — arity is checked, argument types are not, and the result is typed Any. Preloaded untyped base-R builtins (Position, t, Reduce, …) are callable with any number of arguments too.

The RFC's own checklist calls for two doc-site updates that are out of scope for the compiler repo:

• syntaxe.md §12 updated
• docs/philosophy/intro.md and docs/reference/escape-hatches.md updated; the noplayground marker removed from the philosophy example

Concrete spots to update (checked against current main)

• syntaxe.md:479 (§12 "Échappatoires vers du code brut") says "function(...) / R { ... } / JS { ... } n'ont aucune vérification du tout" — no longer accurate for function(...): it now gets an arity check. Needs a sentence distinguishing it from R { ... } / JS { ... } (still fully unchecked).
• docs/philosophy/intro.md:29-38 — the exact motivating example from the RFC (my_addition(num1, num2) on an untyped function(a, b)), currently marked ```typr noplayground because it didn't compile. It should now compile; remove the noplayground marker and verify with npm run check:examples (per this repo's CLAUDE.md, blocks are compiled against the real typr binary in CI).
• docs/reference/escape-hatches.md:27 — "Any function(...) expression is captured as an untyped R function — no type checking on the body." True for the body, but should now also say the call itself is arity-checked and typed Any (with an as! example, mirroring the RFC's Guide-level explanation).
• docs/reference/escape-hatches.md:82 — the escape-hatch summary table's function(...) row (currently | function(...) | no | Untyped R functions |) should reflect that it's callable now.

Note on typR/typr's CLAUDE.md claim

typR/typr's CLAUDE.md says syntaxe.md is "mirrored in typR/typr/syntaxe.md" — that file doesn't currently exist in the compiler repo (only here, at the doc site's root). Worth a look while doing this: either the compiler-repo copy needs to be (re)created, or that CLAUDE.md line is stale and should be corrected.

Test plan

• npm run check:examples passes with the philosophy block's noplayground removed
• npm run build (CI's examples job) green
• Implemented in: filled in on rfcs/0028-calling-untyped-r-functions.md once this lands in the same release

🤖 Generated with Claude Code

https://claude.ai/code/session_01ETPqhgWqDMt7UaUQXdxJmN