From 8544c4099ca8747486410f33cb1cb0c06ba2f684 Mon Sep 17 00:00:00 2001
From: Simon Johansson <simon@findsourcing.com>
Date: Mon, 29 Jan 2024 08:26:04 +0100
Subject: Explain runtime differences for floats

---
 .../chapter0_basics/lesson05_floats/code.gleam     |  3 +++
 .../chapter0_basics/lesson05_floats/text.html      | 24 ++++++++++++++++------
 2 files changed, 21 insertions(+), 6 deletions(-)

(limited to 'src')

diff --git a/src/content/chapter0_basics/lesson05_floats/code.gleam b/src/content/chapter0_basics/lesson05_floats/code.gleam
index 8c4e89a..4241ab4 100644
--- a/src/content/chapter0_basics/lesson05_floats/code.gleam
+++ b/src/content/chapter0_basics/lesson05_floats/code.gleam
@@ -18,6 +18,9 @@ pub fn main() {
   io.debug(1.1 == 1.1)
   io.debug(2.1 == 1.2)
 
+  // Division by zero is not an error
+  io.debug(3.14 /. 0.0)
+
   // Standard library float functions
   io.debug(float.max(2.0, 9.5))
   io.debug(float.ceiling(5.4))
diff --git a/src/content/chapter0_basics/lesson05_floats/text.html b/src/content/chapter0_basics/lesson05_floats/text.html
index cc993c4..1b56d73 100644
--- a/src/content/chapter0_basics/lesson05_floats/text.html
+++ b/src/content/chapter0_basics/lesson05_floats/text.html
@@ -1,15 +1,27 @@
 <p>Gleam's <code>Float</code> type represents numbers that are not integers.</p>
 <p>
-  Unlike many languages Gleam does not have a <code>NaN</code> or
-  <code>Infinity</code> float value.
+  Gleam's numerical operators are not overloaded, so there are dedicatated
+  operators for working with floats.
 </p>
 <p>
-  Gleam's numerical operators are not overloaded, so there are dedictated
-  operators for working with floats.
+  Floats are represented as 64 bit floating point numbers on both the Erlang and
+  JavaScript runtimes. The floating point behaviour is native to their
+  respective runtimes, so their exact behaviour will be slightly different
+  on the two runtimes.
+</p>
+<p>
+  Under the JavaScript runtime, exceeding the maximum (or minimum) representable
+  value for a floating point value will result in <code>Infinity</code> (or
+  <code>-Infinity</code>). Should you try to divide two infinities you will
+  get <code>NaN</code> as a result.
+</p>
+<p>
+  When running on the BEAM any overflow will raise an error. So there is
+  no <code>NaN</code> or <code>Infinity</code> float value in the Erlang
+  runtime.
 </p>
 <p>
-  Floats are represented as 64 bit floating point numbers on both Erlang and
-  JavaScript runtimes.
+  Division by zero will not overflow, but is instead defined to be zero.
 </p>
 <p>
   The
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