I'm looking at using `VisualTransformation` but the documentation for `OffsetMapping` is not clear. ...

# compose

[mkrussel]

I'm looking at using VisualTransformation but the documentation for OffsetMapping is not clear. They value returned from originalToTransformed should be increasing or stay the same. So if I remove the second character the value would stay 0. What should I do if I remove the first character. Is that still 0 or is it -1?

[mkrussel]

Trying to use -1 caused exceptions to get thrown, so it seems like 0 is the correct answer.