A printf / sprintf library for Elixir. It works as a wrapper for :io.format.

When learning Elixir / Erlang, remembering :io.format style is a little tough. This one can be used as syntax sugar, or an util to convert printf format to Elixir (Erlang) one.

defmodule Sample do
  import ExPrintf

  def test do
    printf("number = %d\n", [10])
    # -> number = 10
    IO.puts sprintf("string = %s", ["abc"])
    # -> string = abc

    format = parse_printf("format = %d %.2f\n")
    IO.inspect format
    # -> "format = ~w ~.2f\n"
    :io.format(format, [10, 10.153])
    # -> format = 10 10.15

    IO.puts :io_lib.format(format, [10, 10.153])
    # -> format = 10 10.15
  end
end

Sample.test

$ mix run sample.ex
number = 10
string = abc
"format = ~w ~.2f\n"
format = 10 10.15

$ git clone [email protected]:parroty/exprintf.git
$ cd exprintf
$ ./run_iex.sh
$ iex(1) -> parse_printf("%d")
"~w"

The following hosts a sample dynamo application for the printf format conversion.

http://dynamo-exprintf.herokuapp.com/

• Improve error checking
• Improve format support coverage
  • sprintf("%05d", [-10]) results in "00-10", instead of "-00010".