View Source TypeCheck.TypeError exception (TypeCheck v0.13.7)

Exception to be returned or raised when a value is not of the expected type.

This exception has two fields:

:raw, which will contain the problem tuple of the type check failure.
:message, which will contain a the humanly-readable representation of the raw problem_tuple

:message is constructed from :raw using the TypeCheck.TypeError.DefaultFormatter. (TODO at some point this might be configured to use your custom formatter instead)

Summary

Types

check_name()

The name of the particular check. Might be :no_match for simple types, but for more complex types that have multiple checks, it disambugates between them.

extra_information()

An extra map with any information related to the check that failed.

location()

problem_tuple()

A problem_tuple contains all information about a failed type check.

problematic_value()

The value that was passed in which failed the check.

t()

type_checked_against()

Any built-in TypeCheck struct (c.f. TypeCheck.Builtin.*), whose check(s) failed.

Types

check_name()

@type check_name() :: atom()

The name of the particular check. Might be :no_match for simple types, but for more complex types that have multiple checks, it disambugates between them.

For instance, for TypeCheck.Builtin.List we have :not_a_list, :different_length, and :element_error.

extra_information()

@type extra_information() :: %{optional(atom()) => any()}

An extra map with any information related to the check that failed.

For instance, if the check was a compound check, will contain the field problem: with the child problemtuple as well as :index or :key etc. to indicate _where in the compound structure the check failed.

location()

@type location() :: [] | [file: binary(), line: non_neg_integer()]

problem_tuple()

@type problem_tuple() ::
  {type_checked_against(), check_name(), extra_information(),
   problematic_value()}

A problem_tuple contains all information about a failed type check.

c.f. TypeCheck.TypeError.Formatter.problem_tuple for a more precise definition

problematic_value()

@type problematic_value() :: any()

The value that was passed in which failed the check.

It is included for the easy creation of value did not match y-style messages.

t()

@type t() :: %TypeCheck.TypeError{
  __exception__: true,
  location: location(),
  message: String.t(),
  raw: problem_tuple()
}

type_checked_against()

@type type_checked_against() :: TypeCheck.Type.t()

Any built-in TypeCheck struct (c.f. TypeCheck.Builtin.*), whose check(s) failed.