Elixir v1.10.0-dev Atom View Source

Atoms are constants whose values are their own name.

They are often useful to enumerate over distinct values, such as:

iex> :apple
:apple
iex> :orange
:orange
iex> :watermelon
:watermelon

Atoms are equal if their names are equal.

iex> :apple == :apple
true
iex> :apple == :orange
false

Often they are used to express the state of an operation, by using values such as :ok and :error.

The booleans true and false are also atoms:

iex> true == :true
true
iex> is_atom(false)
true
iex> is_boolean(:false)
true

Elixir allows you to skip the leading : for the atoms false, true, and nil.

Atoms must be composed of Unicode characters such as letters, numbers, underscore, and @. If the keyword has a character that does not belong to the category above, such as spaces, you can wrap it in quotes:

iex> :"this is an atom with spaces"
:"this is an atom with spaces"

Link to this section Summary

Functions

Converts an atom to a charlist.

Converts an atom to a string.

Link to this section Functions

Link to this function

to_charlist(atom)

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to_charlist(atom()) :: charlist()

Converts an atom to a charlist.

Inlined by the compiler.

Examples

iex> Atom.to_charlist(:"An atom")
'An atom'
Link to this function

to_string(atom)

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to_string(atom()) :: String.t()

Converts an atom to a string.

Inlined by the compiler.

Examples

iex> Atom.to_string(:foo)
"foo"