utilities.scm: centralize and modernize addto!

(define-macro) is discouraged in most scheme forms. Change
to (define-syntax), and centralize common macro to utilities.scm

gnucash/report/business-reports/customer-summary.scm

@@ -97,9 +97,6 @@
 
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list 
          (cons table 

gnucash/report/business-reports/easy-invoice.scm

@@ -33,14 +33,12 @@
 (use-modules (srfi srfi-1))
 (use-modules (gnucash gnc-module))
 (use-modules (gnucash gettext))
+(use-modules (gnucash utilities))
 
 (gnc:module-load "gnucash/report/report-system" 0)
 (use-modules (gnucash report standard-reports))
 (use-modules (gnucash report business-reports))
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list
          (cons table

gnucash/report/business-reports/fancy-invoice.scm

@@ -51,14 +51,12 @@
 (use-modules (srfi srfi-1))
 (use-modules (gnucash gnc-module))
 (use-modules (gnucash gettext))
+(use-modules (gnucash utilities))
 
 (gnc:module-load "gnucash/report/report-system" 0)
 (use-modules (gnucash report standard-reports))
 (use-modules (gnucash report business-reports))
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list
          (cons table

gnucash/report/business-reports/invoice.scm

@@ -27,14 +27,12 @@
 (use-modules (srfi srfi-1))
 (use-modules (gnucash gnc-module))
 (use-modules (gnucash gettext))
+(use-modules (gnucash utilities))
 
 (gnc:module-load "gnucash/report/report-system" 0)
 (use-modules (gnucash report standard-reports))
 (use-modules (gnucash report business-reports))
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list
          (cons table

gnucash/report/business-reports/job-report.scm

@@ -46,9 +46,6 @@
 (define desc-header (N_ "Description"))
 (define amount-header (N_ "Amount"))
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list 
          (cons table 

gnucash/report/business-reports/owner-report.scm

@@ -117,9 +117,6 @@
         (else
           (_ "Vendor")))) 
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list 
          (cons table 

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

@@ -22,6 +22,8 @@
 ;; Boston, MA  02110-1301,  USA       gnu@gnu.org
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+(use-modules (gnucash utilities))
+
 ;; returns a list with n #f (empty cell) values 
 (define (gnc:html-make-empty-cell) #f)
 (define (gnc:html-make-empty-cells n)
@@ -854,7 +856,7 @@
                            (disp value))))
         (if (not (or (equal? default-value value)
                      (char=? (string-ref section 0) #\_)))
-            (set! render-list (cons retval render-list)))))
+            (addto! render-list retval))))
     (gnc:options-for-each add-option-if-changed options)
     (if plaintext?
         (string-append

gnucash/report/standard-reports/register.scm

@@ -29,9 +29,6 @@
 
 (gnc:module-load "gnucash/report/report-system" 0)
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 (define (set-last-row-style! table tag . rest)
   (let ((arg-list 
          (cons table 

gnucash/report/standard-reports/transaction.scm

@@ -40,7 +40,7 @@
 
 (define-module (gnucash report standard-reports transaction))
 
-(use-modules (gnucash utilities)) 
+(use-modules (gnucash utilities))
 (use-modules (srfi srfi-1))
 (use-modules (srfi srfi-11))
 (use-modules (srfi srfi-13))
@@ -50,9 +50,6 @@
 
 (gnc:module-load "gnucash/report/report-system" 0)
 
-(define-macro (addto! alist element)
-  `(set! ,alist (cons ,element ,alist)))
-
 ;; Define the strings here to avoid typos and make changes easier.
 (define reportname (N_ "Transaction Report"))
 

libgnucash/scm/utilities.scm

@@ -42,6 +42,7 @@
 (export gnc:error)
 (export gnc:msg)
 (export gnc:debug)
+(export addto!)
 
 ;; Do this stuff very early -- but other than that, don't add any
 ;; executable code until the end of the file if you can help it.
@@ -71,6 +72,10 @@
 (define (gnc:debug . items)
   (gnc-scm-log-debug (strify items)))
 
+(define-syntax addto!
+  (syntax-rules ()
+    ((addto! alist element)
+     (set! alist (cons element alist)))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;  gnc:substring-replace