Candid

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Candid is a binary encoding format for the Internet Computer (ICP).

This library allows to encode and decode Candid messages.

Installation

This package can be installed by adding candid to your list of dependencies in mix.exs:

def deps do
  [
    {:candid, "~> 1.0.0"}
  ]
end

Usage

type_spec = [{:vec, {:record, [{0, :blob}, {1, :blob}]}}]

messages = [
  {"key1", "hello world"},
  {"key2," "hello candid"}
]

^messages = Candid.encode_parameters(type_spec, messages)
|> Candid.decode_parameters()

Support types and shorthands:

For convenience there are type shorthands for :variant, and :record

  • Record: %{name => type_value} e.g. %{a: :text}
  • Variant: [type] e.g. [{:ok, :text}, :error]

Other complex types have to be defined as tuples:

  • Opt: {:opt, type} e.g. {:opt, :nat}
  • Vec: {:vec, type} e.g. {:vec, :nat}

And simple types are just atoms:

  • :null
  • :bool
  • :nat (:nat8, :nat16, :nat32, :nat64)
  • :int (:int8, :int16, :int32, :int64)
  • :float32, :float64
  • :text
  • :principal
  • :blob
  • :empty

Completion

This library does not yet support loading of .did file specifications. PRs and contributions to extend this library are welcome though!

Documentation

The documentation for this library can be found at https://hexdocs.pm/candid.