Biryani
A data conversion and validation toolbox, written in Julia.
Quickstart
julia> Pkg.add("Biryani")
julia> using BiryaniUsage Examples
Example 1: Email validator
Before starting a conversion or validation, the value to convert must be wrapped in a Convertible object. A Convertible contains 3 fields:
- The value
- A conversion context
- An error
julia> convertible = Convertible("John@DOE.name")
Convertible("John@DOE.name",EmptyContext(),nothing)Every converter accepts a Convertible as argument and returns another Convertible:
julia> input_to_email(convertible)
Convertible("john@doe.name",EmptyContext(),nothing)Operations can be chained using the |> operator:
julia> Convertible("John@DOE.name") |> input_to_email
Convertible("john@doe.name",EmptyContext(),nothing)julia> Convertible(" \n ") |> input_to_email
Convertible(nothing,EmptyContext(),nothing)julia> Convertible("John.DOE.name") |> input_to_email
Convertible("john.doe.name",EmptyContext(),"An email must contain exactly one \"@\".")The value of a convertible can be extracted using the to_value function:
julia> Convertible("John@DOE.name") |> input_to_email |> to_value
"john@doe.name"When conversion has failed (the convertible has an error field), to_value throws an exception instead of returning the value:
julia> Convertible("John.DOE.name") |> input_to_email |> to_value
ERROR: An email must contain exactly one "@".
Value: john.doe.name
in to_value at .../Biryani.jl:571
in |> at ./operators.jl:178When you don't want an exception to be thrown, use the to_value_error function instead of to_value. It returns a couple (value, error):
julia> value, error = Convertible("John@DOE.name") |> input_to_email |> to_value_error
("john@doe.name",nothing)
julia> value, error = Convertible("John.DOE.name") |> input_to_email |> to_value_error
("john.doe.name","An email must contain exactly one \"@\".")Example 2: Required email validator
Converters can be combined together to form more complex converters:
julia> Convertible("John@DOE.name") |> input_to_email |> require |> to_value_error
("john@doe.name",nothing)
julia> Convertible(" \n ") |> input_to_email |> require |> to_value_error
(nothing,"Missing value.")
julia> Convertible("John.DOE.name") |> input_to_email |> require |> to_value_error
("john.doe.name","An email must contain exactly one \"@\".")The pipe converter can also be used to chain conversions:
julia> Convertible("John@DOE.name") |> pipe(input_to_email, require) |> to_value_error
("john@doe.name",nothing)You can easily create new converters by combining existing ones:
julia> input_to_required_email = pipe(input_to_email, require)
(anonymous function)
julia> Convertible("John@DOE.name") |> input_to_required_email |> to_value_error
("john@doe.name",nothing)
julia> Convertible("John.DOE.name") |> input_to_required_email |> to_value_error
("john.doe.name","An email must contain exactly one \"@\".")Example 3: Web form validator
A sample validator for a web form containing the following fields:
- Username
- Password (twice)
julia> validate_form = struct(
[
"username" => pipe(strip, require),
"password" => pipe(
test(passwords -> length(passwords) == 2 && passwords[1] == passwords[2], error = "Password mismatch."),
call(passwords -> passwords[1]),
),
"email" => input_to_email,
],
)
julia> input_data = [
"username" => " John Doe\n ",
"password" => ["secret", "secret"],
"email" => "John@DOE.name",
]
julia> result, errors = Convertible(input_data) |> validate_form |> to_value_error
(["password"=>"secret","username"=>"John Doe","email"=>"john@doe.name"],nothing)Note: The same validation using the classic composition of functions instead of |>:
julia> result, errors = to_value_error(validate_form(Convertible(input_data)))
(["password"=>"secret","username"=>"John Doe","email"=>"john@doe.name"],nothing)
julia> to_value_error(validate_form(Convertible(
[
"password" => ["secret", "other secret"],
"email" => " John@DOE.name\n ",
],
)))
(["password"=>ASCIIString["secret","other secret"],"username"=>nothing,"email"=>"john@doe.name"],["password"=>"Password mismatch.","username"=>"Missing value."])
