constant lo hi: uniform over [lo, hi], shrinking toward lo.

constantFrom origin lo hi: uniform over [lo, hi], shrinking toward origin.

A uniform integer in the range, shrinking toward its origin.

A uniform Nat in the range (a negative bound is clamped to 0). The companion of int for indices and other naturals.

A uniform Nat in [lo, hi] (inclusive), with NAT bounds — no toInt. An inverted range (lo > hi) is treated as [lo, lo].

A uniform Nat strictly below n, i.e. in [0, n) — the natural way to pick a valid index into a length-n structure. natBelow 0 yields 0 (there is no value below 0); callers guard the empty case.

A boolean; True shrinks to False.

A character in [lo, hi] (by code point), shrinking toward lo.

Pick one generator uniformly (the list must be non-empty).

element xs generates one of the given VALUES uniformly.

A list whose length is drawn from lenRange, each element from g.

A spread of sample values (run at a fixed size across a few seeds), so a student can SEE what a generator produces (oppi gen sample).