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rand

The rand module provides pseudo-random values backed by Go's math/rand package. It is suitable for simulations, games, and reproducible tests, but not for passwords, tokens, keys, or other security-sensitive work.

import "rand"

print(rand.int(10))
print(rand.float())

Module-level functions use a private, automatically seeded generator.

Module API

FunctionDescription
Rand(seed=...)Create an independent generator; seed defaults to an automatic seed.
int(max=nil)Return a non-negative integer, optionally below max.
float()Return a Float in [0.0, 1.0).
perm(n)Return a random permutation of the integers [0, n).
shuffle(list)Rearrange a list in place and return unit.
norm_float()Draw from the standard normal distribution.
exp_float()Draw from the exponential distribution with rate 1.

int() corresponds to Go's Int63. Passing max selects the bounded Int63n behavior; merging those two Go functions is possible because Goblin supports optional arguments. max must be positive.

shuffle accepts a Goblin list instead of Go's length-and-callback pair. The callback exists only to let Go swap values of arbitrary static types; exposing it would leak that implementation constraint into Goblin.

Independent generators

Rand(seed=...) wraps Go's rand.Rand. Two instances created with the same seed produce the same sequence:

var first = rand.Rand(42)
var second = rand.Rand(42)

print(first.int(1000) == second.int(1000)) # true

A Rand provides the same int, float, perm, shuffle, norm_float, and exp_float methods as the module. It is safe to share between spawned Goblin functions. Concurrent scheduling still determines which caller receives each successive value, so concurrent sequences are not reproducible.

Unlike the old random.Generator, construction always requires a seed. This keeps independent generator creation conceptually aligned with Go's rand.New(rand.NewSource(seed)); use the module functions when reproducibility is not required.

Deliberately omitted Go API

  • Source, Source64, and New are replaced by Rand(seed=...). Go's source interfaces are extension points for Go implementations and should not leak into the Goblin value API.
  • Read is omitted because its Go signature fills a caller-owned byte slice. A future byte-stream API should follow Goblin's common reader protocol rather than expose Go buffer mutation.
  • Integer-width variants (Int31, Int63, Uint32, and Uint64) are not separate functions because Goblin has one signed 64-bit Int type.
  • Seed is omitted. Reproducible state belongs to an explicit Rand rather than mutable module-global state.
  • Zipf is omitted from the initial useful subset because it requires a specialized stateful distribution object.

The former random module and its Python-inspired choice, sample, bounded float, parameterized normal, and parameterized exponential functions were removed. They do not correspond to the Go package being wrapped.