Blank

Experiments with various String#blank? whatchermajiggers.

Benchmarks

Two methods:

• blank? is the native C implementation
• rb_blank? is the straight-forward regex implementation

Tested on three strings:

• st = '________' -- worst case (passes after last char)
• sf = '_______a' -- worst case (fails on last char)
• sg = 'a_______' -- best case (fails on first char)

(Note: underscores represent space chars.)

Ruby 2.1.0

                           user     system      total        real
true (worst case)
st.blank?              0.190000   0.000000   0.190000 (  0.193207)
st.rb_blank?           0.770000   0.000000   0.770000 (  0.772237)
false (worst case)
sf.blank?              0.200000   0.000000   0.200000 (  0.194367)
sf.rb_blank?           0.540000   0.000000   0.540000 (  0.545911)
false (best case)
sg.blank?              0.080000   0.000000   0.080000 (  0.078579)
sg.rb_blank?           0.330000   0.000000   0.330000 (  0.325979)

Ruby 1.9.1

true (worst case)
st.blank?              0.180000   0.000000   0.180000 (  0.184056)
st.rb_blank?           0.720000   0.000000   0.720000 (  0.720227)
false (worst case)
sf.blank?              0.190000   0.000000   0.190000 (  0.187118)
sf.rb_blank?           0.530000   0.000000   0.530000 (  0.533837)
false (best case)
sg.blank?              0.080000   0.000000   0.080000 (  0.081545)
sg.rb_blank?           0.350000   0.000000   0.350000 (  0.348165)