From 08207af2634ca2950be837fb68a442969481b6d3 Mon Sep 17 00:00:00 2001
From: Ryan Rempel <rgrempel@gmail.com>
Date: Sun, 10 Apr 2016 09:57:22 -0500
Subject: [PATCH] Add `trunc`, with a polyfill for browsers that don't support
 it.

---
 src/Math.js   | 4 ++++
 src/Math.purs | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/src/Math.js b/src/Math.js
index 8aad982..e9a7af8 100644
--- a/src/Math.js
+++ b/src/Math.js
@@ -24,6 +24,10 @@ exports.exp = Math.exp;
 
 exports.floor = Math.floor;
 
+exports.trunc = Math.trunc || function (n) {
+  return n < 0 ? Math.ceil(n) : Math.floor(n);
+};
+
 exports.log = Math.log;
 
 exports.max = function (n1) {
diff --git a/src/Math.purs b/src/Math.purs
index 6f4b6cb..a9ba443 100644
--- a/src/Math.purs
+++ b/src/Math.purs
@@ -60,6 +60,10 @@ foreign import sqrt :: Number -> Number
 -- | Returns the tangent of the argument.
 foreign import tan :: Radians -> Number
 
+-- | Truncates the decimal portion of a number. Equivalent to `floor` if the
+-- | number is positive, and `ceil` if the number is negative.
+foreign import trunc :: Number -> Number
+
 infixl 7 %
 
 -- | Computes the remainder after division, wrapping Javascript's `%` operator.