why not account-get-transactions and simpler cash-flow test for already seen split?

[Derek Atkins]

Hi,

This really belongs on the -devel list, as this is a development
question, not a user question....  I've cross posted there, but
please only follow-up to -devel

Larry Evans <cppljevans at cox-internet.com> writes:

[snip]
> both seem to have similar code for processing a set of accounts and 
> their transactions.  In pseudo-code, this idiom is:
>
>    for-each account in set-of-accounts
>      for-each account-split in account
>        transaction = parent-of account-split
>        for-each transaction-split in transaction
>          if(transaction-split != account-split)
>            do-something with transaction-split
>
> Now the function and variable names in actual code and pseudo code are:
>
>    pseudo            actual
>    ------            ------
>    parent-of         gnc:split-get-parent
>    account-split     split
>    transaction-split s
>    transaction       parent
>
> and the if test in actual code is:
>
>    advanced-portfolio:
>
>      same-split? s split
>
>    cash-flow:
>
>      split-in-list? s seen-split-list
>
>      where: seen-split-list is a list of splits which is appended to
>        for each time the test fails.
>
> Could the advanced-portfolio test couldn't be used in place of the
> cash-flow test, and thereby, save some time?

Maybe..  Maybe not.  It also depends a lot on what's done in the 'yes'
and 'no' states of the test.  I'd have to look, which I haven't yet,
to refresh my memory on what exactly is being done.

> Also, could someone explain why there couldn't just be a function:
>
>    gnc:account-get-transactions
>
> which could be used to get the list of transaction in an account instead
> of getting the splits with gnc:account-get-split-list?  

The account keeps a list of splits, not a list of transactions.  Keep
in mind that it's perfectly legal to have a multi-split transaction
where more that one split is in a single account.  So, in the
split-list you'd see two entries for that one transaction -- one for
each split in that account.  So if you created a
gnc:account-get-transactions it would still need to use
gnc:account-get-splits and then walk the list and then keep track of
which transactions have already been seen so you only get transactions
once....  That's pretty expensive, don't you think?

>      It seems from
> looking at the code that the parent is actually a transaction because
> there's this code:
>
>    gnc:transaction-get-splits parent

Yes, the data model is effectively:

Account:
  split-list

Transaction:
  split-list

Split:
  parent -> Transaction
  account -> Account

> TIA.

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord at MIT.EDU                        PGP key available