dune v0.2.1

Dune.Parser.Opts (dune v0.2.1) View Source

Defines the parsing options for Dune, which restrict the code that can safely be executed.

See Dune.Eval.Opts for runtime restriction options.

The available fields are:

  • atom_pool_size: Defines the maximum total number of atoms that can be created. Must be an integer >= 0. Defaults to 5000.
  • max_length: Defines the maximum length of code strings that can be parsed. Defaults to 5000.
  • allowlist: Defines which module and functions are considered safe or restricted. Should be a module implementing the Dune.Allowlist behaviour. Defaults to Dune.Allowlist.Default.

Extra note about atom_pool_size

Atoms are reused from one evaluation to the other so the total is not expected to grow. Atoms will not be leaked.

Also, the atom pool is actually split into several pools: regular atoms, module names, unused variable names, ... So defining a value of 100 does not mean that 100 atoms will be available, but rather 25 of each type.

Atoms being very lightweight, there is no need to use a low value, as long as there is an upper bound preventing atom leaks.

Link to this section Summary

Types

t()

Functions

validate!(opts)

Validates untrusted options from a keyword or a map and returns a Dune.Parser.Opts struct.

Link to this section Types

Link to this type

t()

View Source

Specs

t() :: %Dune.Parser.Opts{
  allowlist: module(),
  atom_pool_size: non_neg_integer(),
  max_length: term()
}

Link to this section Functions

Link to this function

validate!(opts)

View Source

Specs

validate!(Keyword.t() | map()) :: t()

Validates untrusted options from a keyword or a map and returns a Dune.Parser.Opts struct.

Examples 

iex> Dune.Parser.Opts.validate!([])
%Dune.Parser.Opts{atom_pool_size: 5000, allowlist: Dune.Allowlist.Default}

iex> Dune.Parser.Opts.validate!(atom_pool_size: 10)
%Dune.Parser.Opts{atom_pool_size: 10, allowlist: Dune.Allowlist.Default}

iex> Dune.Parser.Opts.validate!(atom_pool_size: -10)
** (ArgumentError) atom_pool_size should be an integer >= 0

iex> Dune.Parser.Opts.validate!(allowlist: DoesNotExists)
** (ArgumentError) could not load module DoesNotExists due to reason :nofile

iex> Dune.Parser.Opts.validate!(allowlist: List)
** (ArgumentError) List does not implement the Dune.Allowlist behaviour