lazy_for

Lazy implementation of Kernel.SpecialForms.for/1 based on streams


Keywords
comprehension, elixir, elixir-lang, stream, stream-processing
License
Other

Documentation

LazyFor

Scene in club lounge, by Thomas Rowlandson

Scene in club lounge, by Thomas Rowlandson

About

The stream-based implementation of Kernel.SpecialForms.for/1.

Has the same syntax as its ancestor, returns a stream.

Currently supports Enum.t() as an input. Examples are gracefully stolen from the ancestor’s docs.

Examples:

iex> import LazyFor
iex> # A list generator:
iex> result = stream n <- [1, 2, 3, 4], do: n * 2
iex> Enum.to_list(result)
[2, 4, 6, 8]

iex> # A comprehension with two generators
iex> result = stream x <- [1, 2], y <- [2, 3], do: x * y
iex> Enum.to_list(result)
[2, 3, 4, 6]

iex> # A comprehension with a generator and a filter
iex> result = stream n <- [1, 2, 3, 4, 5, 6], rem(n, 2) == 0, do: n
iex> Enum.to_list(result)
[2, 4, 6]

iex> users = [user: "john", admin: "meg", guest: "barbara"]
iex> result = stream {type, name} when type != :guest <- users do
...>   String.upcase(name)
...> end
iex> Enum.to_list(result)
["JOHN", "MEG"]

iex> Enum.to_list(stream <<c <- "a b c">>, c != ?\s, do: c)
'abc'

Installation

def deps do
  [
    {:lazy_for, "~> 0.1"}
  ]
end

Changelog

v1.1.0

  • reduce: optional argument is experimentally supported

v1.0.0

  • version bump

v0.3.0

  • optional arguments :into, :uniq, and :take
  • remaining: :reduce

v0.2.0

  • assignments inside the pipeline
  • support for binary comprehensions

Documentation.