anchor.diff:  ----
   Numbers can be placed directly after the `%` to indicate the arguments position,
   note that these numbers are 1-based integers.
  -Numbers are also used by the `#(...)` macro to determine the number of arguments
  -to pass in.
  +Anonymous functions defined by `#(...)` use the highest numbered `%` argument to determine the arity of the anonymous function.
  +
   [source,clojure]
   ----
   user=> (macroexpand `#(println %1 %2))
  
positive.code: 
  == `,` - Whitespace character
  
  Clojure allows `,` to be used as a whitespace character, eg when defining
  maps:
  [source,clojure]
  ----
  user=>(def m {:a 1, :b 2, :c 3}
  {:a 1, :b 2, :c 3}
  ----
  
  
  == `#:` Map Namespace Syntax
  
  Map namespace syntax was added in Clojure 1.9 and is used to specify a default
  namespace context for keys in the map using a `#:ns` prefix, where _ns_ is the
  name of a namespace and the prefix precedes the opening brace `{` of the map.
  
  For example, the following map literal with namespace syntax:
  [source,clojure]
  ----
  #:person{:first "Han"
           :last "Solo"
           :ship #:ship{:name "Millenium Falcon"
                        :model "YT-1300f light freighter"}}
  ----
  is read as:
  [source,clojure]
  ----
  {:person/first "Han"
   :person/last "Solo"
   :person/ship {:ship/name "Millenium Falcon"
                 :ship/model "YT-1300f light freighter"}}
  ----
  
  * <<xref/../../reference/reader#map_namespace_syntax,Reader>>
  
  == `#=` Reader eval
  
  
negative.code: user=> [1 2 3 #_4 5]
  [1 2 3 5]
  ----
  also works. Also note that the discard character works in edn.
  
  A neat trick is that multiple `#_` can be stacked to omit multiple forms
  [source,clojure]
  ----
  user=> {:a 1, #_#_ :b 2, :c 3}
  