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instance method

Enumerator::Lazy#map

lazy.map { |obj| block } → lazy_enumerator

static VALUE
lazy_map(VALUE obj)
{
    if (!rb_block_given_p()) {
        rb_raise(rb_eArgError, "tried to call lazy map without a block");
    }

    return lazy_add_method(obj, 0, 0, Qnil, Qnil, &lazy_map_funcs);
}

Like Enumerable#map, but chains operation to be lazy-evaluated.

Example

(1..Float::INFINITY).lazy.map {|i| i**2 }
#=> #<Enumerator::Lazy: #<Enumerator::Lazy: 1..Infinity>:map>
(1..Float::INFINITY).lazy.map {|i| i**2 }.first(3)
#=> [1, 4, 9]

See also #lazy #reject #grep_v #select also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.0

‹ prev#lazy next ›#reject