The temps a regex replace or replaceAll consumed (the subject that a
previous substitution in a chain produced, a computed replacement) were
released at the end of the statement. A chain of substitutions over a
large string therefore held every intermediate result until the last one
returned. The operands now live in a frame of their own that is released
right after the call, so a chain holds at most its current subject and
result.
Chris Tate
b1614d6e75