@spec charset(name :: valid_charsets()) :: [String.t()]

Returns a charset based on the given name

examples

Examples

lowercased-alphabet

Lowercased alphabet

iex> HypeLib.Utils.String.Generator.charset(:lower)
~w(a b c d e f g h i j k l m n o p q r s t u v w x y z)

uppercased-alphabet

Uppercased alphabet

iex> HypeLib.Utils.String.Generator.charset(:upper)
~w(A B C D E F G H I J K L M N O P Q R S T U V W X Y Z)

numerical-characters

Numerical characters

iex> HypeLib.Utils.String.Generator.charset(:numeric)
~w(0 1 2 3 4 5 6 7 8 9)

hexadecimal-characters

Hexadecimal characters

iex> HypeLib.Utils.String.Generator.charset(:hex)
~w(0 1 2 3 4 5 6 7 8 9 A B C D E F)

iex> HypeLib.Utils.String.Generator.charset(:upper_hex)
~w(0 1 2 3 4 5 6 7 8 9 A B C D E F)

iex> HypeLib.Utils.String.Generator.charset(:lower_hex)
~w(0 1 2 3 4 5 6 7 8 9 a b c d e f)

@spec charsets(charset_names :: [valid_charsets()]) ::
  {:ok, [String.t()]} | {:error, String.t()}

Combines the given charset names to one big charset

examples

Examples

It should return an error tuple when the given charset names are empty

iex> HypeLib.Utils.String.Generator.charsets([])
{:error, "Empty charset names list provided"}

It should return a combination of the lowercased alphabet and numerical numbers when the charset names are [:lower, :numeric]

iex> alias HypeLib.Utils.String.Generator
...> Generator.charsets([:lower, :numeric])
{:ok, Generator.charset(:lower) ++ Generator.charset(:numeric)}

It should return an combination of the lower- and uppercased alphabet including numerical characters when the charset names are [:lower, :upper, :numeric]

iex> alias HypeLib.Utils.String.Generator
...> Generator.charsets([:lower, :upper, :numeric])
{:ok, Generator.charset(:lower) ++ Generator.charset(:upper) ++ Generator.charset(:numeric)}

@spec charsets!(charset_names :: [valid_charsets()]) :: [String.t()] | none()

Tries to generate one big charset based on the given charset names.

When the charset can't be generated then an error will be raised. This could happen in the following cases:

• the given list is empty
• the given list contains invalid charset names (via TypeCheck runtime check) (see Expected arguments section)

expected-arguments

Expected arguments

examples

Examples

iex> HypeLib.Utils.String.Generator.charsets!(~w(lower numeric)a)
~w(a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9)

iex> HypeLib.Utils.String.Generator.charsets!([])
** (RuntimeError) Empty charset names list provided

@spec generate_string(
  desired_length :: pos_integer(),
  charset :: [String.t()],
  current_string :: String.t()
) :: {:ok, String.t()} | {:error, String.t()}

Generates a string of the desired length with random characters from the given charset.

examples

Examples

It should return an error when the given charset is empty

iex> HypeLib.Utils.String.Generator.generate_string(2, [])
{:error, "Invalid charset length"}

Generate a string with a length of 2 and a given charset of ~w(a)

iex> HypeLib.Utils.String.Generator.generate_string(2, ~w(a))
{:ok, "aa"}

Generate a random string with a length of 16 and the alphabet given as charset

iex> alias HypeLib.Utils.String.Generator
...> {:ok, result} = Generator.generate_string(16, Generator.charset(:lower))
...> String.length(result)
16

It returns the current string if it has already the desired length

iex> alias HypeLib.Utils.String.Generator
...> Generator.generate_string(1, Generator.charset(:lower), "a")
{:ok, "a"}

It returns the current string if it is already longer than the desired length

iex> alias HypeLib.Utils.String.Generator
...> Generator.generate_string(1, Generator.charset(:lower), "aa")
{:ok, "aa"}

@spec generate_string!(
  desired_length :: pos_integer(),
  charset :: [String.t()],
  current_string :: String.t()
) :: String.t() | none()

Generates a string of the desired length and given charset.

Hint 1: You can use these functions to quickly generate a charset:

• HypeLib.Utils.String.Generator.charset/1
• HypeLib.Utils.String.Generator.charsets!/1

Hint 2: We don't provide any charsets for special characters since this is highly application specific.

When the string can't be generated then an error will be raised. This could happen in the following cases:

• the given charset is an empty list
• the arguments don't match the expected types (via TypeCheck runtime check) (see Expected arguments section)

expected-arguments

Expected arguments

examples

Examples

It should raise an runtime error when the charset is an empty list.

iex> HypeLib.Utils.String.Generator.generate_string!(2, [])
** (RuntimeError) Invalid charset length

Generate a string with a length of 2 and a given charset of ~w(a)

iex> HypeLib.Utils.String.Generator.generate_string!(2, ~w(a))
"aa"

Generate a random string with a length of 16 and the alphabet given as charset

iex> alias HypeLib.Utils.String.Generator
...> Generator.generate_string!(16, Generator.charset(:lower))
...> |> String.length()
16

It returns the current string if it has already the desired length

iex> alias HypeLib.Utils.String.Generator
...> Generator.generate_string!(1, Generator.charset(:lower), "a")
"a"

It returns the current string if it is already longer than the desired length

iex> alias HypeLib.Utils.String.Generator
...> Generator.generate_string!(1, Generator.charset(:lower), "aa")
"aa"