[GNC-dev] Planning for 4.x - progress in scheme code

[Christopher Lam]

Hi Users and Devs

Those with an eye on maint & master will notice I've continued cleaning up
reports and report infrastructure heavily. I hope these efforts are
appreciated. In my subjective view, the cleaned up reports are neater and
easier to follow, and less wordy.

I have two major approaches in use:
1. minimise set! in reports -- using set! in scheme is prone to
incomprehensible code; it allows modifications of vars out of scope. Also
see
https://www.gnu.org/software/guile/manual/html_node/Variables-and-the-VM.html#Variables-and-the-VM
comment about using set! in scheme.
2. try eradicate gnc:commodity-collector modification in reports -- using
them is mostly used to keep track of monetary amounts, and they are
*always* converted to a target currency for display or other processing
(otherwise why keep track of them?). Therefore commodity-collector logic
should be hidden away. I've added gnc:collector+ and gnc:collector- to add
a list of collectors, and can be used similar to + or - as in
(gnc:collector+ assets liabilities) whereby assets & liabilities are
collectors, and this will create a *new* collector with the added amounts.
This is a neater approach, and avoids such hacks as
https://github.com/Gnucash/gnucash/blob/3.7/gnucash/report/report-system/html-acct-table.scm#L732
which is a hack to ensure the correct collector is modified in scheme.
Conclusion: best abstract commodity-collectors away, transforming report
code from accumulator to functional approach, such as:
https://github.com/Gnucash/gnucash/commit/80296a3c

While this is ongoing, there are PRs waiting in github, awaiting further
consideration. I've refrained from merging too much work into master
because I think many will require careful review or debate.

1. https://github.com/Gnucash/gnucash/pull/459 - to implement book-specific
accounting-period. This work is complete but creates two confusing
accounting periods. I am not sure how to create a transition from global to
book property.

2. https://github.com/Gnucash/gnucash/pull/463 - to refactor
advanced-portfolio.scm -- this will be a long-term project because this
report is too complex. I'll keep this one for last.

3. https://github.com/Gnucash/gnucash/pull/477 - for book-saved-reports --
this branch works well but needs modification to options.scm. I think this
will depend on c++ options work to be completed.

4. https://github.com/Gnucash/gnucash/pull/500 - GST/VAT Reports upgrade --
this work will augment income-gst-statement.scm to also present reports
suitable for UK VAT and Australian BAS returns. The only remaining issue
here is a decision on *how* to tag UK EC VAT and Sales accounts; currently
they rely on *ECGOODS* and *ECVAT* present in account description. This is
a fine hack, but a hack nonetheless. Is there a better approach?

5. https://github.com/Gnucash/gnucash/pull/520 - redirect jqplot to chartjs
-- I think this is ready to be merged in. Any objections?

6. https://github.com/Gnucash/gnucash/pull/535 - unify job & owner - I
think this is nearly ready. It augments these reports to allow linking
invoices <-> payments. But I am still not sure how to present the
aging-table especially with overpayments and credit-notes not paired
correctly.

7. https://github.com/Gnucash/gnucash/pull/538 - refactor-aging ditto

8. https://github.com/Gnucash/gnucash/pull/544 - qif upgrade - instead of
saving account full-name in qif-import-map, save the account guid instead.
will need more testing especially the qif mapping needs to be useful with
multiple books.

9. https://github.com/Gnucash/gnucash/pull/558 - remove "Report Title"
option - I think could be merged in already.

10. https://github.com/Gnucash/gnucash/pull/576 - ensure budget estimator
can ignore closing entries -- I think it could also be merged in.

11. https://github.com/Gnucash/gnucash/pull/585 - fix internal budget
amounts to ignore global account-reversal property. I think this is
complete, however, there is work pending to fix amount signs on existing
budgets. This requires coding to guard future books from being modified by
previous versions, and I have no idea how to code this.

Any constructive comments welcome. That's all for now!