class method · added in Ruby 3.2

Enumerator.product

[Elem] (*::_EachEntry[Elem]) -> ::Enumerator::Product[Elem]

Enumerator.product(*enums) → enumerator

Enumerator.product(*enums) { |elts| ... } → enumerator

static VALUE
enumerator_s_product(int argc, VALUE *argv, VALUE klass)
{
    VALUE enums = Qnil, options = Qnil, block = Qnil;

    rb_scan_args(argc, argv, "*:&", &enums, &options, &block);

    if (!NIL_P(options) && !RHASH_EMPTY_P(options)) {
        rb_exc_raise(rb_keyword_error_new("unknown", rb_hash_keys(options)));
    }

    VALUE obj = enum_product_initialize(argc, argv, enum_product_allocate(rb_cEnumProduct));

    if (!NIL_P(block)) {
        enum_product_run(obj, block);
        return Qnil;
    }

    return obj;
}

Generates a new enumerator object that generates a Cartesian product of given enumerable objects. This is equivalent to Enumerator::Product.new.

Example

e = Enumerator.product(1..3, [4, 5])
e.to_a #=> [[1, 4], [1, 5], [2, 4], [2, 5], [3, 4], [3, 5]]
e.size #=> 6

When a block is given, calls the block with each N-element array generated and returns nil.

Ruby version changes

3.2
- Enumerator.product has been added. Enumerator::Product is the implementation. [Feature #18685]

See also .produce #+ .new #each also in 4.1 · 3.4 · 3.3 · 3.2

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