Why doesn't Ruby have a real StringBuffer or StringIO?

Question

I recently read a nice post on using StringIO in Ruby. What the author doesn\'t mention, though, is that StringIO is just an \"I.\" There\'s no \

Answer 1

I did some benchmarks and the fastest approach is using the String#<< method. Using StringIO is a little bit slower.

s = ""; Benchmark.measure{5000000.times{s << "some string"}}
=>   3.620000   0.100000   3.720000 (  3.970463)

>> s = StringIO.new; Benchmark.measure{5000000.times{s << "some string"}}
=>   4.730000   0.120000   4.850000 (  5.329215)

Concatenating strings using the String#+ method is the slowest approach by many orders of magnitude:

s = ""; Benchmark.measure{10000.times{s = s + "some string"}}
=>   0.700000   0.560000   1.260000 (  1.420272)

s = ""; Benchmark.measure{10000.times{s << "some string"}}
=>   0.000000   0.000000   0.000000 (  0.005639)

So I think the right answer is that the equivalent to Java's StringBuffer is simply using String#<< in Ruby.