Specs

exists?(String.t() | atom()) :: boolean()

Returns true if the passed-in value resembles an existing atom and false if it does not.

Examples

iex> exists?(:foo)
true
iex> exists?("yes")
true
iex> exists?("bar")
false

iex> exists?("false")
true
iex> exists?("nil")
true

Specs

from_string(String.t() | atom()) :: atom() | nil

If able, casts the string to an existing atom, returning nil if not.

Also passes atoms through, for convenience.

Examples

iex> from_string("ok")
:ok

iex> from_string("error")
:error

iex> from_string("true")
true

iex> from_string("false")
false

iex> from_string("nil") # `nil` is, itself, an atom
nil

iex> from_string("what's all this then?")
nil

iex> from_string(:foo)
:foo