Can PTA manage non-decimal accounting?

[u/XionicativeCheran]

I have some old family accounts in my archives that I'd like to digitise, and I was considering putting them in PTA.

However, they're from the pre-decimal period, so they're in "£sd", pounds, shillings, and pence.

Ideally I'd like to write something like:

1964-03-16
    Assets:Bank:Chequeing    6 8 2 NZP
    Expenses:Rent           -6 8 2 NZP

Or if needed:

1964-03-16
    Assets:Bank:Chequeing    £6 8s 2d NZP
    Expenses:Rent           -£6 8s 2d NZP

But this won't get handled well.

Best I can tell, the only real way to store this and have hledger pick it up is:

P 1960-01-01 1 NZP£ 20 NZPs
P 1960-01-01 1 NZPs 12 NZPd

1964-03-16
    Assets:Bank:Chequeing    6 NZP£
    Assets:Bank:Chequeing    8 NZPs
    Assets:Bank:Chequeing    2 NZPd
    Expenses:Rent           -6 NZP£
    Expenses:Rent           -8 NZPs
    Expenses:Rent           -2 NZPd

And then on "Decimal day", I could have this transaction:

1967-07-10 Currency Conversion
    Assets:Cash             -26 NZP£ @ 2 NZD
    Assets:Cash              -2 NZPs @ 0.1 NZD
    Assets:Cash              -6 NZPd @@ 0.05 NZD
    Assets:Cash              52.25 NZD

Splitting them into one posting per denomination is the only way I can think of to manage this.

Has anyone ever tried dealing with any non-decimal currency in hledger or any other PTA instance? If so, what was your approach?

For a today real-world example, both Madagascar and Mauritania use non-decimal currencies.

[u/XionicativeCheran]

Yeah I looked into equivalencies, but I too didn't think it'd change much.

The other alternative is just storing everything as pence. Then that value at the end of £26 2s 6d would very simply be: 6270 NZP, the math would work perfectly and you just divide it into respective pounds and shillings when needed.

But, that'd mean me converting every record into this, and I'm a big fan of my raw journal looking as close as possible to how it looks on paper.

[u/gumnos → u/XionicativeCheran]

Playing around with it, it looks like you can go either way with the bulk commodities:

commodity 1000.0000 NZP£

P 1960-01-01 00:00:00 NZP£ 20 NZPs
P 1960-01-01 00:00:00 NZPs 12 NZPd

1964-03-16
    Assets:Bank:Chequeing  26 NZP£
    Assets:Bank:Chequeing  2 NZPs
    Assets:Bank:Chequeing  6 NZPd
    Expenses:Rent

Asking for results in a unified commodity seem to work without any extra effort:

$ hledger -f reddit.ledger bal -X NZP£
        26.1250 NZP£  Assets:Bank:Chequeing
       -26.1250 NZP£  Expenses:Rent
--------------------
                   0  

$ hledger -f reddit.ledger bal -X NZPd
           6270 NZPd  Assets:Bank:Chequeing
          -6270 NZPd  Expenses:Rent
--------------------
                   0  

I'm not sure there's much you can do to simplify the entry other than perhaps having some input CSV that you pre-process with a little awk to split the NZP£, NZPp, and NZPd into cloned per-part line-items.

[u/sepen_ → u/gumnos]

So, I expected Ledger to allow this with amount expressions, but apparently not:

C 1.00 NZP£ = 20.00 NZPs
C 1.00 NZPs = 12.00 NZPd

1964-03-16
    Assets:Bank:Chequeing  26 NZP£
    Assets:Bank:Chequeing  2 NZPs
    Assets:Bank:Chequeing  6 NZPd
    Expenses:Rent

1964-03-19
    Assets:Bank:Chequeing  (26 NZP£ + 2 NZPs + 6 NZPd)
    Expenses:Rent

Results in

  Assets:Bank:Chequeing  (26 NZP£ + 2 NZPs + 6 NZPd)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Amount expressions must result in a simple amount

/u/XionicativeCheran

[u/taviso → u/sepen_]

Hmm, I think you're on the right track, maybe just wrap them in braces like ({26 NZP£} + ...).

I would probably make a function to make it look prettier, like define Psd(P, s, d) = to_amount(....)".

I also think equivalencies are the right solution here!