Add round-number-to-decimal.el

init.el

@@ -63,6 +63,7 @@
 (load "gnu-c-header.el")
 (load "gobgen/gobgen.el")
 (load "toggle-window-split.el")
+(load "round-number-to-decimals.el")
 
 (add-hook 'c-mode-hook 'helm-gtags-mode)
 (add-hook 'c-mode-hook 'which-func-mode)

round-number-to-decimals.el

@@ -0,0 +1,19 @@
+(defun get-number-at-point ()
+  (interactive)
+  (skip-chars-backward "0123456789.-")
+  (or (looking-at "[0123456789.-]+")
+      (error "No number at point"))
+  (string-to-number (match-string 0)))
+
+(defun round-number-at-point-to-decimals (decimal-count)
+  (interactive "NDecimal count: ")
+  (let ((mult (expt 10 decimal-count)))
+    (replace-match (number-to-string
+              (/
+               (fround
+                (*
+                 mult
+                 (get-number-at-point)))
+                mult)))))
+
+(global-set-key (kbd "C-c r") 'round-number-at-point-to-decimals)