Equalable

v0.1.1

Equalable v0.1.1 Eq View Source

Utilities which help to implement and use Equalable protocol for pair of types/values

Link to this section Summary

Types

left()
right()

Functions

left <|> right

Infix shortcut for Eq.not_equal?/2

Examples

iex> use Eq
Eq
iex> 1 <|> 1
false
iex> 1 <|> :hello
true
left <~> right

Infix shortcut for Eq.equal?/2

__using__(_)

Imports Eq.defequalable/3, Eq.<~>/2 and Eq.<|>/2 macro helpers

defequalable(arg1, arg2, list)

Helper to define symmetric equivalence relation, accepts two term :: type pairs and block of code where relation is described

equal?(left, right)

Is left equivalent to right? Here are provided examples for standard Erlang types, for more complex examples look defequalable/3 documetation

not_equal?(left, right)

Is left not equivalent to right? For more complex examples look equal?/2 and defequalable/3 documetation

Link to this section Types

Link to this type

left() View Source 
left() :: term()

Link to this type

right() View Source 
right() :: term()

Link to this section Functions

Link to this macro

left <|> right View Source (macro)

Infix shortcut for Eq.not_equal?/2

Examples 

iex> use Eq
Eq
iex> 1 <|> 1
false
iex> 1 <|> :hello
true
Link to this macro

left <~> right View Source (macro)

Infix shortcut for Eq.equal?/2

Examples 

iex> use Eq
Eq
iex> 1 <~> 1
true
iex> 1 <~> :hello
false
Link to this macro

__using__(_) View Source (macro)

Imports Eq.defequalable/3, Eq.<~>/2 and Eq.<|>/2 macro helpers

Examples 

iex> use Eq
Eq
iex> 1 <~> 1
true
iex> 1 <|> 2
true
Link to this macro

defequalable(arg1, arg2, list) View Source (macro)

Helper to define symmetric equivalence relation, accepts two term :: type pairs and block of code where relation is described.

Examples 

iex> quote do
...>   use Eq
...>   defmodule Foo do
...>     defstruct [:value, :meta]
...>   end
...>   defmodule Bar do
...>     defstruct [:value, :meta]
...>   end
...>   defequalable %Foo{value: left} :: Foo, %Foo{value: right} :: Foo do
...>     Eq.equal?(left, right)
...>   end
...>   defequalable %Foo{value: left} :: Foo, %Bar{value: right} :: Bar do
...>     Eq.equal?(left, right)
...>   end
...>   defequalable %Foo{value: left} :: Foo, right :: Integer do
...>     Eq.equal?(left, right)
...>   end
...> end
...> |> Code.compile_quoted
iex> quote do
...>   x = %Foo{value: 1, meta: 1}
...>   y = %Foo{value: 1, meta: 2}
...>   Eq.equal?(x, y) && Eq.equal?(y, x)
...> end
...> |> Code.eval_quoted
...> |> elem(0)
true
iex> quote do
...>   x = %Foo{value: 1, meta: 1}
...>   y = %Bar{value: 1, meta: 2}
...>   Eq.equal?(x, y) && Eq.equal?(y, x)
...> end
...> |> Code.eval_quoted
...> |> elem(0)
true
iex> quote do
...>   x = %Foo{value: 1, meta: 1}
...>   y = 1
...>   Eq.equal?(x, y) && Eq.equal?(y, x)
...> end
...> |> Code.eval_quoted
...> |> elem(0)
true
Link to this function

equal?(left, right) View Source 
equal?(left(), right()) :: bool()

Is left equivalent to right? Here are provided examples for standard Erlang types, for more complex examples look defequalable/3 documetation.

Examples 

iex> Eq.equal?(1, 1)
true
iex> Eq.equal?(1, 1.0)
true
iex> Eq.equal?(1, 2)
false
iex> Eq.equal?(1, :hello)
false

iex> Eq.equal?([1, 2, 3], [1, 2, 3])
true
iex> Eq.equal?([[1, 2, 3], [4]], [[1, 2, 3], [4]])
true
iex> Eq.equal?([1, 2, 3], [1, 2])
false
iex> Eq.equal?([[1, 2, 3], [4]], [[1, 2, 3], [5]])
false

iex> Eq.equal?({1, 2, 3}, {1, 2, 3})
true
iex> Eq.equal?({{1, 2, 3}, {4}}, {{1, 2, 3}, {4}})
true
iex> Eq.equal?({1, 2, 3}, {1, 2})
false
iex> Eq.equal?({{1, 2, 3}, {4}}, {{1, 2, 3}, {5}})
false

iex> Eq.equal?(%{a: 1, b: 2}, %{a: 1, b: 2})
true
iex> Eq.equal?(%{a: 1, b: %{c: 2}}, %{a: 1, b: %{c: 2}})
true
iex> Eq.equal?(%{a: 1, b: 2}, %{a: 1})
false
iex> Eq.equal?(%{a: 1, b: 2}, %{a: 1, c: 2})
false

iex> a = 1
iex> x = URI.parse("http://hello.world")
iex> y = URI.parse("http://foo.bar")
iex> z = URI.parse("http://foo.bar")
iex> Eq.equal?(a, x)
false
iex> Eq.equal?(x, a)
false
iex> Eq.equal?(x, y)
false
iex> Eq.equal?(y, x)
false
iex> Eq.equal?(y, z)
true
iex> Eq.equal?(z, y)
true
Link to this function

not_equal?(left, right) View Source 
not_equal?(left(), right()) :: bool()

Is left not equivalent to right? For more complex examples look equal?/2 and defequalable/3 documetation.

Examples 

iex> Eq.not_equal?(1, 0)
true
iex> Eq.not_equal?(1, 1)
false