collect_concat

        # Enumerator::Lazy.collect_concat

(from ruby core)
### Implementation from Lazy
---
    collect_concat()

---

Returns a new lazy enumerator with the concatenated results of running
`block` once for every element in the lazy enumerator.

    ["foo", "bar"].lazy.flat_map {|i| i.each_char.lazy}.force
    #=> ["f", "o", "o", "b", "a", "r"]

A value `x` returned by `block` is decomposed if either of the following
conditions is true:

*   `x` responds to both each and force, which means that `x` is a lazy
    enumerator.
*   `x` is an array or responds to to_ary.


Otherwise, `x` is contained as-is in the return value.

    [{a:1}, {b:2}].lazy.flat_map {|i| i}.force
    #=> [{:a=>1}, {:b=>2}]


(This method is an alias for Enumerator::Lazy#flat_map.)

Returns a new lazy enumerator with the concatenated results of running
`block` once for every element in the lazy enumerator.

    ["foo", "bar"].lazy.flat_map {|i| i.each_char.lazy}.force
    #=> ["f", "o", "o", "b", "a", "r"]

A value `x` returned by `block` is decomposed if either of the following
conditions is true:

*   `x` responds to both each and force, which means that `x` is a lazy
    enumerator.
*   `x` is an array or responds to to_ary.


Otherwise, `x` is contained as-is in the return value.

    [{a:1}, {b:2}].lazy.flat_map {|i| i}.force
    #=> [{:a=>1}, {:b=>2}]