regex               input     expected  actual    bug?      

-------------------------------------------------------------

(^)                 12345     x12345    x12345              

($)                 12345     12345x    12345x              

(^)|($)             12345     x12345x   x12345x             

($)|(^)             12345     x12345x   x12345x             

2                   12345     1x345     1x345               

(^)|2               12345     x1x345    x1x345              

2|(^)               12345     x1x345    x1x345              

($)|2               12345     1x345x    1x345x              

2|($)               12345     1x345x    1x345x              

(2)|(^)             12345     x1x345    x1x345              

(^)|(2)             12345     x1x345    x1x345              

(2)|($)             12345     1x345x    1x345x              

($)|(2)             12345     1x345x    1x345x              

((2)|(^)).          12345     xx45      xx45                

((^)|(2)).          12345     xx45      xx45                

.((2)|($))          12345     x34x      x34x                

.(($)|(2))          12345     x34x      x34x                

(^)|6               12345     x12345    x12345              

6|(^)               12345     x12345    x12345              

($)|6               12345     12345x    12345x              

6|($)               12345     12345x    12345x              

2|6|(^)             12345     x1x345    x1x345              

2|(^)|6             12345     x1x345    x1x345              

6|2|(^)             12345     x1x345    x1x345              

6|(^)|2             12345     x1x345    x1x345              

(^)|6|2             12345     x1x345    x1x345              

(^)|2|6             12345     x1x345    x1x345              

2|6|($)             12345     1x345x    1x345x              

2|($)|6             12345     1x345x    1x345x              

6|2|($)             12345     1x345x    1x345x              

6|($)|2             12345     1x345x    1x345x              

($)|6|2             12345     1x345x    1x345x              

($)|2|6             12345     1x345x    1x345x              

2|4|(^)             12345     x1x3x5    x1x3x5              

2|(^)|4             12345     x1x3x5    x1x3x5              

4|2|(^)             12345     x1x3x5    x1x3x5              

4|(^)|2             12345     x1x3x5    x1x3x5              

(^)|4|2             12345     x1x3x5    x1x3x5              

(^)|2|4             12345     x1x3x5    x1x3x5              

2|4|($)             12345     1x3x5x    1x3x5x              

2|($)|4             12345     1x3x5x    1x3x5x              

4|2|($)             12345     1x3x5x    1x3x5x              

4|($)|2             12345     1x3x5x    1x3x5x              

($)|4|2             12345     1x3x5x    1x3x5x              

($)|2|4             12345     1x3x5x    1x3x5x              

x{0}((2)|(^))       12345     x1x345    x1x345              

x{0}((^)|(2))       12345     x1x345    x1x345              

x{0}((2)|($))       12345     1x345x    1x345x              

x{0}(($)|(2))       12345     1x345x    1x345x              

x*((2)|(^))         12345     x1x345    x1x345              

x*((^)|(2))         12345     x1x345    x1x345              

x*((2)|($))         12345     1x345x    1x345x              

x*(($)|(2))         12345     1x345x    1x345x              

x{0}^               12345     x12345    x12345              

x{0}$               12345     12345x    12345x              

(x{0}^)|2           12345     x1x345    x1x345              

(x{0}$)|2           12345     1x345x    1x345x