[timfennis]

A number literal in a generic function's body that the function's parameters reached became an extra type parameter, which each call settled: fn pair(x) => [x, 1] made pair(2.5) [2.5, 1.0]. That needed its own machinery: literal type parameters with bounds in each scheme, per-instance literal types read by the compiler, and special Int rules for calls from an earlier REPL line and for function values. As a result the same code typed differently in a file and in the REPL. A review of the type checker found that no realistic program used it.

A generic body's literals are now decided by the body alone, before the function is generalised, with the same look-ahead as literals anywhere else. They're never type parameters, so a file and the REPL type a program the same way.

Behaviour changes:

• fn fact(n) => if n < 2 { 1 } else { n * fact(n - 1) } called as fact(5.0) is an analysis error pointing into the body. Writing 1.0 makes it work for Ints and Floats alike.
• fn pair(x) => [x, 1] only takes Ints, fn k(x) => [x, "b"] only Strings, and fn f(xs) { xs.push(1); xs } only List<Int>.
• fn inc(x) => x + 1 still takes Floats, since +(Float, Int) exists, and fib(10.0) still works. A literal at the call still adapts: let r: Float = g(3) makes the 3 a Float.
• Next to fn f(xs: List<Any>), fn f(x) => f([x]) now makes x an Any, so it calls the List<Any> overload instead of reporting growing recursion.

Removed: Scheme.literals and literal_nodes, LiteralBounds, instantiate_literals, resolve_bounds, with_literals_named, literals_tied_to_parameters, number_literals, the Int rules for earlier batches and function values, the per-instance literal_types in the analysis, layout and compiler, and the bound de-duplication only copied literals needed (−353 lines of Rust).

A second commit sorts the unsettled literals by a key computed once, which was quadratic for a list of 20,000 values.

The manual's function and augmented-assignment pages are updated.

🤖 Generated with Claude Code

[chatgpt-codex-connector]

Codex Review Summary: ✅ Completed

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-11-13T17:21:33.086594Z	a9aa78a	PR opened

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