diff options
| -rw-r--r-- | lisp/ldg-commodities.el | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/lisp/ldg-commodities.el b/lisp/ldg-commodities.el index 59b26ff9..a7f58f40 100644 --- a/lisp/ldg-commodities.el +++ b/lisp/ldg-commodities.el @@ -33,6 +33,10 @@ :type 'string :group 'ledger-reconcile) +(defcustom ledger-scale 10000 + "The 10 ^ maximum number of digits you would expect to appear in your reports. +This is a cheap way of getting around floating point silliness in subtraction") + (defun ledger-split-commodity-string (str) "Split a commoditized string, STR, into two parts. Returns a list with (value commodity)." @@ -81,7 +85,9 @@ Returns a list with (value commodity)." (defun -commodity (c1 c2) "Subtract C2 from C1, ensuring their commodities match." (if (string= (cadr c1) (cadr c2)) - (list (- (car c1) (car c2)) (cadr c1)) + ; the scaling below is to get around inexact subtraction results where, for example + ; 1.23 - 4.56 = -3.3299999999999996 instead of -3.33 + (list (/ (- (* ledger-scale (car c1)) (* ledger-scale (car c2))) ledger-scale) (cadr c1)) (error "Can't subtract different commodities %S from %S" c2 c1))) (defun +commodity (c1 c2) @@ -97,7 +103,7 @@ Returns a list with (value commodity)." (setq new-str (append new-str (list ch)))))))) (defun ledger-string-to-number (str &optional decimal-comma) - "improve builtin string-to-number by handling internationalization, and return nil of number can't be parsed" + "improve builtin string-to-number by handling internationalization, and return nil if number can't be parsed" (let ((nstr (if (or decimal-comma (assoc "decimal-comma" ledger-environment-alist)) (ledger-strip str ?.) |