Introducing Erlang highlights

content/reviews/books/introducing-erlang.md

@@ -1,6 +1,7 @@
 +++
 title = "Introducing Erlang: Getting Started in Functional Programming - Simon St. Laurent"
 date = 2020-08-05
+updated = 2020-10-26
 
 [taxonomies]
 tags = ["books", "reviews", "simon st laurent", "erlang", "it", 
@@ -34,3 +35,46 @@ learning path, the book says _nothing_ about those things.
 
 For seeing how the language looks like, it's a good book. For something more
 _real_... far away from it.
+
+## Highlights
+
+>  go to the command line and type erl 
+
+*Note*: `erl` is the Erlang Shell.
+
+>  3> 2#1010111. 
+
+*Note*: Binary notation.
+
+>  4> 16#cafe 
+
+*Note*: Hex notation.
+
+>  FallVelocity = fun(Distance) -> math:sqrt(2 * 9.8 * Distance) end.
+
+*Note*: `fun` creates an anonymous function; it is then associated with the
+name `FallVelocity` (all variables need to start with an upcase letter).
+
+>  -module(drop).<br>
+>  -export([fall_velocity/1, mps_to_mph/1, mps_to_kph/1]).<br><br>
+>  fall_velocity(Distance) -> math:sqrt(2 * 9.8 * Distance). <br>
+>  mps_to_mph(Mps) -> 2.23693629 * Mps.<br>
+>  mps_to_kph(Mps) -> 3.6 * Mps.
+
+>  -module(combined).<br>
+>  -export([height_to_mph/1]).<br>
+>  -import(drop, [fall_velocity/1]).<br>
+>  -import(convert, [mps_to_mph/1]).<br>
+>  height_to_mph(Meters) -> mps_to_mph(fall_velocity(Meters)). 
+
+>  In Erlang, greater-than-or-equal-to is written as >=, and
+>  less-than-or-equal-to as =<. Don’t make them look like arrows. 
+
+>  try <br>
+>    math:sqrt(2 * Gravity * Distance) <br>
+>  catch <br>
+>    error:Error -> {error, Error} end.
+
+>  Creating a map requires a different syntax presenting keys and values:<br>
+>  1> Planemos = #{ earth => 9.8, moon => 1.6, mars => 3.71 }.<br>
+>  #{earth => 9.8,mars => 3.71,moon => 1.6}