Add /-r, /-c and /-f

README.md

@@ -148,6 +148,9 @@ Most functions of this module only handle ```decimal``` type. ```integer```s are
 * ```(defun round* (decimals:integer x:decimal)``` : Reversed round function
 * ```(defun floor* (decimals:integer x:decimal)``` : Reversed floor function
 * ```(defun ceiling* (decimals:integer x:decimal)``` : Reversed ceiling function
+* ```(defun /-r (decimals:integer x:decimal y:decimal)```: Rounded division
+* ```(defun /-f (decimals:integer x:decimal y:decimal)```: Floored division
+* ```(defun /-c (decimals:integer x:decimal y:decimal)```: Ceiled division
 * ```(defun log10:decimal (x)``` : Returns the log of x base 10, rounded to 12 decimals
 * ```(defun safe-log (x y default)``` : Log of Y base X, but returns default when y <= 0
 * ```(defun safe-ln (x:decimal default:decimal)``` : Natural log of x, but returns default when x <= 0

docs/source/util-math.rst

@@ -496,6 +496,47 @@ As a result ``safe-/`` never fails (Division by *0.0* is not possible anymore).
   0.0
 
 
+In Pact, the native divide ``(/)`` function can produce up to 255 decimals. That's why
+it's almost mandatory to "post-process" the division by rounding, ceiling or flooring.
+
+The three functions below help for doing in a single operation: the division and the post-processing.
+
+/-r
+~~~
+*decimals* ``integer`` *x* ``decimal`` *y* ``decimal`` *→* ``decimal``
+
+Divide and round to a given number of decimals.
+
+.. code:: lisp
+
+  pact> (/-r 4 2.0 3.0)
+  0.6667
+
+/-f
+~~~
+*decimals* ``integer`` *x* ``decimal`` *y* ``decimal`` *→* ``decimal``
+
+Divide and floor to a given number of decimals.
+
+.. code:: lisp
+
+  pact> (/-f 4 2.0 3.0)
+  0.6666
+
+/-c
+~~~
+*decimals* ``integer`` *x* ``decimal`` *y* ``decimal`` *→* ``decimal``
+
+Divide and ceil to a given number of decimals.
+
+.. code:: lisp
+
+  pact> (/-c 4 2.0 3.0)
+  0.6667
+
+
+
+
 
 Average and Median
 -------------------

pact/contracts/util-math.pact

@@ -236,6 +236,18 @@
     "Reversed ceiling function"
     (ceiling x decimals))
 
+  (defun /-r (decimals:integer x:decimal y:decimal)
+    "Rounded division"
+    (round (/ x y) decimals))
+
+  (defun /-f (decimals:integer x:decimal y:decimal)
+    "Floored division"
+    (floor (/ x y) decimals))
+
+  (defun /-c (decimals:integer x:decimal y:decimal)
+    "Ceiled division"
+    (ceiling (/ x y) decimals))
+
   ;;; Log functions
   (defun log10:decimal (x)
     "Returns the log of x base 10, rounded to 12 decimals"