The stringdiff unit has these functions:

- Compare original string and second string and compute a "difference map"

between the two strings.

- Use original string and difference map and produce second string. Reverse of computeDiff

-The stringdiff unit has these functions:

-　Compare original string and second string and compute a "difference map"

　between the two strings.

-　Use original string and difference map and produce second string. Reverse of computeDiff