BSI Range-Encoding: internal support for setting field values

[travisturner]

Given a frame, columnID, field, and value, look up the field in the schema for the frame and set the appropriate bits for the field (probably need to set both 1's and 0's)

In the example in #616, the following function:

frame.setFieldValue(colID uint64, field string, val int64) {}

called with:

setFieldValue(1, "age", 35)

Would perform the equivalent of the following (note that we are setting the flip of 35 in 7-bit binary (0100011 to 1011100):

SetBit(frame="f", columnID=1, rowID=0)
ClearBit(frame="f", columnID=1, rowID=1)
ClearBit(frame="f", columnID=1, rowID=2)
SetBit(frame="f", columnID=1, rowID=3)
SetBit(frame="f", columnID=1, rowID=4)
SetBit(frame="f", columnID=1, rowID=5)
ClearBit(frame="f", columnID=1, rowID=6)
SetBit(frame="f", columnID=1, rowID=7)

We should be aware that by having val be an int64 we are limiting ourselves to 64-bit range-encoded values when technically we don't have a limit with the implementation.

A basic POC can be found at https://github.com/travisturner/bit-slice-index