1 ^((<|>)?=?)s*(\s*[v=]*\s*([0-9]+)\.([0-9]+)\.([0-9]+)(-[0-9]+-?)?([a-zA-Z-+][a-zA-Z0-9-.:]*)?)$|^$
   2 >=0.6.0-,>=,>,0.6.0-,0,6,0,,-
   3 =0.6.0-,=,,0.6.0-,0,6,0,,-
   4 0.6.0-,,,0.6.0-,0,6,0,,-
   5 <=0.6.0-,<=,<,0.6.0-,0,6,0,,-
   6 >=0.6.0-a:b-c.d,>=,>,0.6.0-a:b-c.d,0,6,0,,-a:b-c.d
   7 =0.6.0-a:b-c.d,=,,0.6.0-a:b-c.d,0,6,0,,-a:b-c.d
   8 0.6.0+a:b-c.d,,,0.6.0+a:b-c.d,0,6,0,,+a:b-c.d
   9 <=0.6.0+a:b-c.d,<=,<,0.6.0+a:b-c.d,0,6,0,,+a:b-c.d
  10 a
  11 b
  12 y
  13 z
  14 B
  15 Y
  16 Z
  17 -
  18 +