[report-utilities] gnc:account-get-balances-at-dates adjustment

(Release Note - developer section)

Modification to gnc:account-get-balances-at-dates.

formerly it would accept an optional #:ignore-closing? boolean to skip
closing transactions.

it would be more general to accept a #:split->amount function whose
default is xaccSplitGetAmount. calling (split->amount split) should
return amount from the split. if the function returns #f, it
effectively skips the split. this will allow a more general
account-balance list accumulator, allowing novel balance strategies
e.g. split->amount may test split void status and return the split
xaccSplitVoidFormerAmount, test description/memo and return an amount
depending on description contents, or test the split and return 1 or 0
which will return a tally of splits.

the direct equivalence for the previous #:ignore-closing? keyword
argument is #:split->amount (lambda (s) (and (not (xaccTransGetIsClosingTxn
(xaccSplitGetParent s))) (xaccSplitGetAmount s)))

NOTE: the modifications to category-barchart.scm and net-charts.scm
will use the #:split->amount kwarg as well.

This function is extensively tested in the commit
53cab269f4

gnucash/report/report-system/report-utilities.scm

@@ -432,9 +432,16 @@ flawed. see report-utilities.scm. please update reports.")
 ;; a list of balances along the way at dates specified in dates-list.
 ;; in:  account
 ;;      dates-list (list of time64)
-;;      ignore-closing? - if #true, will skip closing entries
+;;      split->amount - an unary lambda. calling (split->amount split)
+;;      returns a number, or #f which effectively skips the split.
 ;; out: (list bal0 bal1 ...), each entry is a gnc-monetary object
-(define* (gnc:account-get-balances-at-dates account dates-list #:key ignore-closing?)
+;;
+;; NOTE a prior incarnation accepted a #:ignore-closing? boolean
+;; keyword which can be reproduced via #:split->amount (lambda (s)
+;; (and (not (xaccTransGetIsClosingTxn (xaccSplitGetParent s)))
+;; (xaccSplitGetAmount s)))
+(define* (gnc:account-get-balances-at-dates
+          account dates-list #:key (split->amount xaccSplitGetAmount))
   (define (amount->monetary bal)
     (gnc:make-gnc-monetary (xaccAccountGetCommodity account) bal))
   (let loop ((splits (xaccAccountGetSplitList account))
@@ -460,10 +467,7 @@ flawed. see report-utilities.scm. please update reports.")
      (else
       (let* ((this (car splits))
              (rest (cdr splits))
-             (currentbal (if (and ignore-closing?
-                                  (xaccTransGetIsClosingTxn (xaccSplitGetParent this)))
-                             currentbal
-                             (+ (xaccSplitGetAmount this) currentbal)))
+             (currentbal (+ (or (split->amount this) 0) currentbal))
              (next (and (pair? rest) (car rest))))
 
         (cond

gnucash/report/standard-reports/category-barchart.scm

@@ -361,12 +361,18 @@ developing over time"))
           (define account-balances-alist
             (map
              (lambda (acc)
-               (cons acc
-                     (map
-                      (if (reverse-balance? acc) gnc:monetary-neg identity)
-                      (gnc:account-get-balances-at-dates
-                       acc dates-list
-                       #:ignore-closing? (gnc:account-is-inc-exp? acc)))))
+               (let ((ignore-closing? (not (gnc:account-is-inc-exp? acc))))
+                 (cons acc
+                       (map
+                        (if (reverse-balance? acc) gnc:monetary-neg identity)
+                        (gnc:account-get-balances-at-dates
+                         acc dates-list
+                         #:split->amount
+                         (lambda (s)
+                           (and (or ignore-closing?
+                                    (not (xaccTransGetIsClosingTxn
+                                          (xaccSplitGetParent s))))
+                                (xaccSplitGetAmount s))))))))
              accounts))
 
           ;; Creates the <balance-list> to be used in the function

gnucash/report/standard-reports/net-charts.scm

@@ -251,10 +251,16 @@
     ;; gets an account alist balances
     ;; output: (list acc bal0 bal1 bal2 ...)
     (define (account->balancelist account)
-      (cons account
-            (gnc:account-get-balances-at-dates
-             account dates-list
-             #:ignore-closing? (gnc:account-is-inc-exp? account))))
+      (let ((ignore-closing? (not (gnc:account-is-inc-exp? account))))
+        (cons account
+              (gnc:account-get-balances-at-dates
+               account dates-list
+               #:split->amount
+               (lambda (s)
+                 (and (or ignore-closing?
+                          (not (xaccTransGetIsClosingTxn
+                                (xaccSplitGetParent s))))
+                      (xaccSplitGetAmount s)))))))
 
     ;; This calculates the balances for all the 'account-balances' for
     ;; each element of the list 'dates'. Uses the collector->monetary