Reports: don't use gnc:html-table-append-column!

This function is inefficient. Each column appended will require
scanning every row of existing html-table, scanning the row's elements
and appending the desired data.

It is much more efficient to build a html-table by append rows instead
-- html-table rows are stored in reverse, and each appended row is
built using (cons newrow existing-rows).

gnucash/report/reports/example/hello-world.scm

@@ -427,8 +427,10 @@ new, totally cool report, consult the mailing list ~a.")
 
       (if (not (null? list-val))
           (let ((table (gnc:make-html-table)))
-            (gnc:html-table-append-column! 
-             table (map symbol->string list-val))
+            (for-each
+             (lambda (cell)
+               (gnc:html-table-append-row! table (list (symbol->string cell))))
+             list-val)
             (gnc:html-table-set-style! table "table"
              'attribute (list "style" "width:200px"))
             (gnc:html-table-set-caption! table 

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

@@ -35,6 +35,7 @@
 (use-modules (gnucash app-utils))
 (use-modules (gnucash reports cash-flow-calc))
 (use-modules (gnucash report))
+(use-modules (srfi srfi-26))
 
 (define reportname (N_ "Cash Flow Barchart"))
 
@@ -327,6 +328,17 @@
 
           (if (and non-zeros show-table?)
               (let* ((table (gnc:make-html-table)))
+
+                (define (add-row date in out net)
+                  (gnc:html-table-append-row!
+                   table
+                   (cons date
+                         (map (cut gnc:make-html-table-cell/markup "number-cell" <>)
+                              (append
+                               (if show-in?  (list in)  '())
+                               (if show-out? (list out) '())
+                               (if show-net? (list net) '()))))))
+
                 (gnc:html-table-set-col-headers!
                  table (append (list (G_ "Date"))
                                (if show-in? (list (G_ "Money In")) '())
@@ -335,22 +347,9 @@
 
                 (gnc:html-document-add-object!
                  doc (gnc:make-html-text (gnc:html-markup-h3 (G_ "Overview:"))))
-                (gnc:html-table-append-column! table (append date-string-list (list "Total")))
-
-                (if show-in?
-                    (gnc:html-table-append-column! table (append in-list (list total-in))))
-                (if show-out?
-                    (gnc:html-table-append-column! table (append out-list (list total-out))))
-                (if show-net?
-                    (gnc:html-table-append-column! table (append net-list (list total-net))))
-
-                ;; set numeric columns to align right
-                (for-each
-                 (lambda (col)
-                   (gnc:html-table-set-col-style!
-                    table col "td"
-                    'attribute (list "class" "number-cell")))
-                 '(1 2 3))
+
+                (for-each add-row date-string-list in-list out-list net-list)
+                (add-row (G_ "Total") total-in total-out total-net)
 
                 (gnc:html-document-add-object! doc table))))
 

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

@@ -229,11 +229,7 @@
     ;; This exchanges the commodity-collector 'c' to one single
     ;; 'report-currency' according to the exchange-fn. Returns a gnc:monetary
     (define (collector->monetary c date)
-      (if (not (number? date))
-          (throw 'wrong))
-      (gnc:sum-collector-commodity
-       c report-currency
-       (lambda (a b) (exchange-fn a b date))))
+      (gnc:sum-collector-commodity c report-currency (cut exchange-fn <> <> date)))
 
     ;; gets an account alist balances
     ;; output: (list acc bal0 bal1 bal2 ...)
@@ -425,21 +421,20 @@
                              (list (G_ "Net Profit"))
                              (list (G_ "Net Worth")))
                          '())))
-                   (gnc:html-table-append-column! table date-string-list)
-                   (when show-sep?
-                     (gnc:html-table-append-column! table minuend-balances)
-                     (gnc:html-table-append-column! table subtrahend-balances))
 
-                   (if show-net?
-                       (gnc:html-table-append-column! table difference-balances))
-
-                   ;; set numeric columns to align right
                    (for-each
-                    (lambda (col)
-                      (gnc:html-table-set-col-style!
-                       table col "td"
-                       'attribute (list "class" "number-cell")))
-                    '(1 2 3))
+                    (lambda (date minuend subtrahend difference)
+                      (gnc:html-table-append-row!
+                       table
+                       (cons date
+                             (map
+                              (cut gnc:make-html-table-cell/markup "number-cell" <>)
+                              (append (if show-sep? (list minuend subtrahend) '())
+                                      (if show-net? (list difference) '()))))))
+                    date-string-list
+                    minuend-balances
+                    subtrahend-balances
+                    difference-balances)
 
                    (gnc:html-document-add-object! document table)))