BCD List to HEX List

[John Machin]

bryanjugglercryptographer at yahoo.com wrote:

>My version assumes three subroutines: extracting
> nibbles, shifting, and adding, Those are pretty simple, so I asked
> if he needed them rather than presenting them.
> Assuming we have
> them, the algorithm is three lines long.

Perhaps you could enlighten us by publishing (a) the spec for each of
the get_nibble(s), shift, and add subroutines (b) the three-line
algorithm (c) what the algorithm is intended to achieve ...

>
> He took a while to state the problem, but was clear from the start
> that he had lists of digits rather than an integer datatype.

Yes, input was a list [prototyping a byte array] of decimal digits. The
OUTPUT was also a list of something. A few messages later, it became
clear that the output desired was a list of hexadecimal digits. Until
he revealed that the input was up to 24 decimal digits,  I was pursuing
the notion that a solution involving converting decimal to binary (in a
32-bit long) then to hexadecimal was the way to go.

What is apparently needed is an algorithm for converting a "large"
number from a representation of one base-10 digit per storage unit to
one of a base-16  digit per storage unit,  when the size of the number
exceeds the size (8, 16, 32, etc bits) of the "registers" available. Is
that what you have?

Cheers,
John