Inspect.Opts — Elixir v1.16.3

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# View Source Inspect.Opts (Elixir v1.16.3)

Defines the options used by the `Inspect` protocol.

The following fields are available:

- `:base` - prints integers and binaries as `:binary`, `:octal`, `:decimal`, or `:hex`. Defaults to `:decimal`.

- `:binaries` - when `:as_binaries` all binaries will be printed in bit syntax.

  When `:as_strings` all binaries will be printed as strings, non-printable bytes will be escaped.

  When the default `:infer`, the binary will be printed as a string if `:base` is `:decimal` and if it is printable, otherwise in bit syntax. See `String.printable?/1` to learn when a string is printable.

- `:charlists` - when `:as_charlists` all lists will be printed as charlists, non-printable elements will be escaped.

  When `:as_lists` all lists will be printed as lists.

  When the default `:infer`, the list will be printed as a charlist if it is printable, otherwise as list. See `List.ascii_printable?/1` to learn when a charlist is printable.

- `:custom_options` (since v1.9.0) - a keyword list storing custom user-defined options. Useful when implementing the `Inspect` protocol for nested structs to pass the custom options through.

  It supports some pre-defined keys:

  - `:sort_maps` (since v1.14.4) - if set to `true`, sorts key-value pairs in maps. This can be helpful to make map inspection deterministic for testing, given maps key order is random.

- `:inspect_fun` (since v1.9.0) - a function to build algebra documents. Defaults to `Inspect.Opts.default_inspect_fun/0`.

- `:limit` - limits the number of items that are inspected for tuples, bitstrings, maps, lists and any other collection of items, with the exception of printable strings and printable charlists which use the `:printable_limit` option. If you don't want to limit the number of items to a particular number, use `:infinity`. It accepts a positive integer or `:infinity`. Defaults to `50`.

- `:pretty` - if set to `true` enables pretty printing. Defaults to `false`.

- `:printable_limit` - limits the number of characters that are inspected on printable strings and printable charlists. You can use `String.printable?/1` and `List.ascii_printable?/1` to check if a given string or charlist is printable. If you don't want to limit the number of characters to a particular number, use `:infinity`. It accepts a positive integer or `:infinity`. Defaults to `4096`.

- `:safe` - when `false`, failures while inspecting structs will be raised as errors instead of being wrapped in the `Inspect.Error` exception. This is useful when debugging failures and crashes for custom inspect implementations. Defaults to `true`.

- `:structs` - when `false`, structs are not formatted by the inspect protocol, they are instead printed as maps. Defaults to `true`.

- `:syntax_colors` - when set to a keyword list of colors the output is colorized. The keys are types and the values are the colors to use for each type (for example, `[number: :red, atom: :blue]`). Types can include `:atom`, `:binary`, `:boolean`, `:list`, `:map`, `:number`, `:regex`, `:string`, `:tuple`, or some types to represent AST like `:variable`, `:call`, and `:operator`. Custom data types may provide their own options. Colors can be any `IO.ANSI.ansidata/0` as accepted by `IO.ANSI.format/1`. A default list of colors can be retrieved from `IO.ANSI.syntax_colors/0`.

- `:width` - number of characters per line used when pretty is `true` or when printing to IO devices. Set to `0` to force each item to be printed on its own line. If you don't want to limit the number of items to a particular number, use `:infinity`. Defaults to `80`.

# Summary

## Types

color_key()
t()

## Functions

default_inspect_fun()

Returns the default inspect function.

default_inspect_fun(fun)

Sets the default inspect function.

new(opts)

Builds an `Inspect.Opts` struct.

# Types

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# color_key()

View Source

    @type color_key() :: atom()

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# t()

View Source

    @type t() :: %Inspect.Opts{
      base: :decimal | :binary | :hex | :octal,
      binaries: :infer | :as_binaries | :as_strings,
      char_lists: term(),
      charlists: :infer | :as_lists | :as_charlists,
      custom_options: keyword(),
      inspect_fun: (any(), t() -> Inspect.Algebra.t()),
      limit: non_neg_integer() | :infinity,
      pretty: boolean(),
      printable_limit: non_neg_integer() | :infinity,
      safe: boolean(),
      structs: boolean(),
      syntax_colors: [{color_key(), IO.ANSI.ansidata()}],
      width: non_neg_integer() | :infinity
    }

# Functions

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# default_inspect_fun()

View Source (since 1.13.0)

    @spec default_inspect_fun() :: (term(), t() -> Inspect.Algebra.t())

Returns the default inspect function.

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# default_inspect_fun(fun)

View Source (since 1.13.0)

    @spec default_inspect_fun((term(), t() -> Inspect.Algebra.t())) :: :ok

Sets the default inspect function.

Set this option with care as it will change how all values in the system are inspected. The main use of this functionality is to provide an entry point to filter inspected values, in order for entities to comply with rules and legislations on data security and data privacy.

It is extremely discouraged for libraries to set their own function as this must be controlled by applications. Libraries should instead define their own structs with custom inspect implementations. If a library must change the default inspect function, then it is best to ask users of your library to explicitly call `default_inspect_fun/1` with your function of choice.

The default is `Inspect.inspect/2`.

## Examples

    previous_fun = Inspect.Opts.default_inspect_fun()

    Inspect.Opts.default_inspect_fun(fn
      %{address: _} = map, opts ->
        previous_fun.(%{map | address: "[REDACTED]"}, opts)

      value, opts ->
        previous_fun.(value, opts)
    end)

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# new(opts)

View Source (since 1.13.0)

    @spec new(keyword()) :: t()

Builds an `Inspect.Opts` struct.