Array#map vs. Enumerator::Lazy for memory-efficient transformations

When processing large datasets in Ruby, the choice between immediate array mapping and lazy evaluation significantly impacts memory consumption. Using Array#map immediately materializes a complete new array in memory before any subsequent operations are performed. This can lead to high RSS usage if the source collection is large and only a subset is eventually required.

Conversely, Enumerator::Lazy avoids intermediate array allocations by processing elements one by one on demand. While this reduces memory overhead for short-circuiting pipelines, it introduces overhead due to the enumerator object and state management. The decision often hinges on whether the workflow requires the full transformed set or if it can terminate early once a condition is met.

• At what dataset size does the overhead of Enumerator::Lazy outweigh the memory savings in Ruby?
• How does lazy evaluation behave when chained with terminal methods like first versus intermediate transformations?