rand

Random numbers for simulations, games, and similar uses. Draws use ECMAScript Math.random: approximately uniform, engine-defined, unseeded, and not reproducible across runs or engines. They are not cryptographically secure; never use them for tokens, access codes, or UUIDs. These procedures run only as statements, so expressions, including the steps of map, cannot draw. Draw in a procedure and store the result.

Write these names after rand::, as in rand::unit.

unit

proc unit()! num

Returns an approximately uniform number from 0 up to but excluding 1.

int

proc int(start! num, end! num)! num

Returns an approximately uniform integer from start up to but excluding end; rand::int(1, 7) rolls a die. Bounds must be safe integers with start < end and a span of at most 2^53; otherwise the call fails with Conflict.

units

proc units(count! num)* num -> num

Draws count independent unit values as index -> value, with indices from zero and multiplicity one. Indices keep equal draws distinct and pair separate draws; they do not order Bag enumeration. The count must be a nonnegative integer within the Bag-total limit; otherwise the call fails with Conflict. Work limits use ordinary LimitExceeded failures without publishing partial results.

ints

proc ints(count! num, start! num, end! num)* num -> num

Draws count independent int values as index -> value, with the same indices, count rules, and limits as units. Bounds follow int and are validated even when the count is zero.