1.31: Non-print-like reports are adding decimal marks

[usaAmch]

Given that a commodity that uses thousand separators and no decimal places is declared, when running non-print-like reports (like bal, reg, bs), the output includes the decimal mark even thought it is not needed.

Steps to reproduce

• Generate a new ledger file with the following content:

  commodity JPY
     format 1,000. JPY

   payee open
   payee test

   account asset
   account equity
   account expense

   2023-01-01 open
     asset             1,000 JPY
     equity

   2023-01-02 test
     expense               1 JPY
     asset

• Execute the following command: hledger -f test.journal bal

Expected Result

• bal report should show equity amount as 1,000 JPY

             999 JPY  asset
          -1,000 JPY  equity
               1 JPY  expense
--------------------
                   0 

Current Result

• bal report shows equity amount as 1,000. JPY, note the extra . at the end of the amount.

             999 JPY  asset
         -1,000. JPY  equity
               1 JPY  expense
--------------------
                   0 

Extra Info

% hledger --version
hledger 1.31, mac-aarch64

[simonmichael]

This change in 1.31:

print no longer displays numbers with a single digit group mark and no decimal mark, which are ambiguous and hard to re-parse. Now if a number has digit group marks the decimal mark will always be shown also. Eg 1,000 (where the comma is a thousands separator) is now shown as 1,000..

was intended to affect only print and print-like reports. Thanks for the report! Claim your https://hledger.org/REGRESSIONS.html#regression-bounty when convenient.

As mentioned in chat, I plan to keep this behaviour for the print-like reports and revert it for the others, and document the following policy at hledger manual > PART 3: REPORTING CONCEPTS > Amount formatting:

Three rough categories of hledger output exist, differing in their intended consumers and whether they show ambiguous amounts (amounts with just one digit group mark and no decimal mark):

1. "hledger-readable output" - should be readable by hledger and humans

• all reports showing full journal entries (print, import, close, rewrite..)
• shows amounts with their original journal precisions
• adds a trailing decimal mark to ambiguous amounts
• can be parsed reliably

2. "human-readable output" - usually for humans

• all other reports
• shows amounts with their commodity's standard display precision
• shows a decimal mark when displaying decimal digits
• can show ambiguous amounts
• can be parsed reliably in the context of a known report (because of consistent style, within each commodity)

3. "machine-readable output" - usually for other software

• the csv/tsv/json/sql output from all reports
• shows amounts with no digit group marks
• shows a period decimal mark (.) when displaying decimal digits
• can be parsed reliably

Today I'm leaning toward not treating HTML output specially, so a print-like HTML report such as the journal view in hledger-web could show trailing decimal marks, like print in the terminal. This would look like:

[simonmichael]

Rationale: we aim to be free of period/comma decimal mark bias, and to support arbitrary digit groups; and print-like reports show original journal precisions which can be inconsistent; so without the trailing decimal mark, print's HTML output could sometimes be hard for humans to read too. If you disagree, let me know.