Comp-3 function

[mlbelobraydi]

Is your feature request related to a problem? Please describe.
The production data has several fields that are comp-3

Describe the solution you'd like
The positions in bytes are less than the ending number of digits. The pic_signed function does not account for this and an additional function needs to be created

Describe alternatives you've considered
Tried to find a way to modify pic_signed and it isn't possible and will require a new function for comp-3

Additional context
Information on Comp-3 can be found here
http://www.3480-3590-data-conversion.com/article-packed-fields.html

[mlbelobraydi]

Does this fix pic_V999

[mlbelobraydi]

Reviewing work completed by @skylerbast in Cobol_types Comp3 function, the pic_signed function should be able to handle this request. Unknown how it unpacks the fields to create the correct decimal places.

[skylerbast]

You are referring to the Gas or Oil Production ledgers such as the ones described here, right? Unfortunately the pic_signed function won't work, we'll have to add a new one to handle COMP-3. The function you referred to in my repo should work with minimal modification. I'll make a PR and add it shortly.

The reason the pic_signed function doesn't work is because the "signed" data items aren't compressed like the COMP-3 ones are; the signed numbers are stored as the EBCDIC representation of the numerals and the sign is overpunched (1,234 would be stored as 0xF1F2F3C4, and -1,234 would be stored as 0xF1F2F3C4 for example). Therefore, to hold an digit number, the signed field must be bytes in size. So there's a small bit of space saved by overpunching the sign, but nothing huge. By contrast, COMP-3 numbers store the digits as their decimal values (rather than the code representing the digit's numeral), and adds a nibble at the end to represent the sign (1,234 would be stored as 0x01234C and -1,234 would be stored as 0x01234D). To store an digit number, the COMP-3 format requires bytes.

[mlbelobraydi]

Started new branch to try and solve the addition of comp3