defmodule RDF.Vocabulary.Namespace do
@moduledoc """
An RDF vocabulary as a `RDF.Namespace`.
`RDF.Vocabulary.Namespace` modules represent a RDF vocabulary as a `RDF.Namespace`.
They can be defined with the `defvocab/2` macro of this module.
RDF.ex comes with predefined modules for some fundamental vocabularies in
the `RDF.NS` module.
"""
alias RDF.Description
alias RDF.Utils.ResourceClassifier
import RDF.Utils, only: [downcase?: 1]
@type t :: module
# Note: We're not using :code.priv_dir/1 here on purpose, since vocabulary files should be
# searched in the vocabs dir of the project in which the vocabulary namespace is defined.
@vocabs_dir "priv/vocabs"
defmacro __using__(_opts) do
quote do
import unquote(__MODULE__)
end
end
@doc """
Defines a `RDF.Namespace` module for a RDF vocabulary.
"""
defmacro defvocab(name, opts) do
strict = strict?(opts)
base_iri = base_iri!(opts)
file = filename!(opts)
{terms, data} =
case source!(opts) do
{:terms, terms} -> {terms, nil}
{:data, data} -> {rdf_data_vocab_terms(data, base_iri), data}
end
unless Mix.env() == :test do
IO.puts("Compiling vocabulary namespace for #{base_iri}")
end
ignored_terms = ignored_terms!(opts)
terms =
terms
|> term_mapping!(opts)
|> Map.drop(MapSet.to_list(ignored_terms))
|> validate_terms!
|> validate_characters!(opts)
|> validate_case!(data, base_iri, opts)
case_separated_terms = group_terms_by_case(terms)
lowercased_terms = Map.get(case_separated_terms, :lowercased, %{})
quote do
vocabdoc = Module.delete_attribute(__MODULE__, :vocabdoc)
defmodule unquote(name) do
@moduledoc vocabdoc
@behaviour Elixir.RDF.Namespace
import Kernel,
except: [
min: 2,
max: 2,
div: 2,
rem: 2,
abs: 1,
ceil: 1,
floor: 1,
elem: 2,
send: 2,
apply: 2,
destructure: 2,
get_and_update_in: 2,
get_in: 2,
pop_in: 2,
put_in: 2,
put_elem: 2,
update_in: 2,
raise: 2,
reraise: 2,
inspect: 2,
struct: 1,
struct: 2,
use: 1,
use: 2
]
if unquote(file) do
@external_resource unquote(file)
end
@base_iri unquote(base_iri)
@spec __base_iri__ :: String.t()
def __base_iri__, do: @base_iri
@strict unquote(strict)
@spec __strict__ :: boolean
def __strict__, do: @strict
@terms unquote(Macro.escape(terms))
@impl Elixir.RDF.Namespace
def __terms__, do: @terms |> Map.keys()
@spec __term_aliases__ :: [atom]
def __term_aliases__ do
@terms
|> Enum.filter(fn {_, term} -> term != true end)
|> Enum.map(fn {alias, _} -> alias end)
end
@ignored_terms unquote(Macro.escape(ignored_terms))
@doc """
Returns all known IRIs of the vocabulary.
"""
@spec __iris__ :: [Elixir.RDF.IRI.t()]
def __iris__ do
@terms
|> Enum.map(fn
{term, true} -> term_to_iri(@base_iri, term)
{_alias, term} -> term_to_iri(@base_iri, term)
end)
|> Enum.uniq()
end
define_vocab_terms(unquote(lowercased_terms), unquote(base_iri))
@impl Elixir.RDF.Namespace
@dialyzer {:nowarn_function, __resolve_term__: 1}
def __resolve_term__(term) do
case @terms[term] do
nil ->
if @strict or MapSet.member?(@ignored_terms, term) do
{:error,
%Elixir.RDF.Namespace.UndefinedTermError{
message: "undefined term #{term} in strict vocabulary #{__MODULE__}"
}}
else
{:ok, term_to_iri(@base_iri, term)}
end
true ->
{:ok, term_to_iri(@base_iri, term)}
original_term ->
{:ok, term_to_iri(@base_iri, original_term)}
end
end
if not @strict do
def unquote(:"$handle_undefined_function")(term, []) do
if MapSet.member?(@ignored_terms, term) do
raise UndefinedFunctionError
else
term_to_iri(@base_iri, term)
end
end
def unquote(:"$handle_undefined_function")(term, [subject | objects]) do
objects =
case objects do
[objects] when is_list(objects) -> objects
_ -> objects
end
if MapSet.member?(@ignored_terms, term) do
raise UndefinedFunctionError
else
case subject do
%Description{} -> subject
_ -> Description.new(subject)
end
|> Description.add({term_to_iri(@base_iri, term), objects})
end
end
end
end
end
end
@doc false
defmacro define_vocab_terms(terms, base_iri) do
terms
|> Stream.filter(fn
{term, true} -> valid_term?(term)
{_, _} -> true
end)
|> Stream.map(fn
{term, true} -> {term, term}
{term, original_term} -> {term, original_term}
end)
|> Enum.map(fn {term, iri_suffix} ->
iri = term_to_iri(base_iri, iri_suffix)
quote do
@doc "<#{unquote(to_string(iri))}>"
def unquote(term)(), do: unquote(Macro.escape(iri))
@doc "`RDF.Description` builder for `#{unquote(term)}/0`"
def unquote(term)(subject, object)
def unquote(term)(%Description{} = subject, object) do
Description.add(subject, {unquote(Macro.escape(iri)), object})
end
def unquote(term)(subject, object) do
Description.new(subject, init: {unquote(Macro.escape(iri)), object})
end
# Is there a better way to support multiple objects via arguments?
@doc false
def unquote(term)(subject, o1, o2),
do: unquote(term)(subject, [o1, o2])
@doc false
def unquote(term)(subject, o1, o2, o3),
do: unquote(term)(subject, [o1, o2, o3])
@doc false
def unquote(term)(subject, o1, o2, o3, o4),
do: unquote(term)(subject, [o1, o2, o3, o4])
@doc false
def unquote(term)(subject, o1, o2, o3, o4, o5),
do: unquote(term)(subject, [o1, o2, o3, o4, o5])
end
end)
end
defp strict?(opts),
do: Keyword.get(opts, :strict, true)
defp base_iri!(opts) do
base_iri = Keyword.fetch!(opts, :base_iri)
unless is_binary(base_iri) and String.ends_with?(base_iri, ~w[/ # .]) do
raise RDF.Namespace.InvalidVocabBaseIRIError,
"a base_iri without a trailing '/' or '#' is invalid"
else
base_iri
end
end
defp source!(opts) do
cond do
Keyword.has_key?(opts, :file) ->
{:data, filename!(opts) |> RDF.read_file!(base_iri: nil)}
rdf_data = Keyword.get(opts, :data) ->
{:data, raw_rdf_data(rdf_data)}
terms = Keyword.get(opts, :terms) ->
{:terms, terms_from_user_input!(terms)}
true ->
raise KeyError, key: ~w[terms data file], term: opts
end
end
defp terms_from_user_input!(terms) do
# TODO: find an alternative to Code.eval_quoted - We want to support that the terms can be given as sigils ...
{terms, _} = Code.eval_quoted(terms, [], rdf_data_env())
Enum.map(terms, fn
term when is_atom(term) ->
term
term when is_binary(term) ->
String.to_atom(term)
term ->
raise RDF.Namespace.InvalidTermError,
"'#{term}' is not a valid vocabulary term"
end)
end
defp raw_rdf_data(%Description{} = rdf_data), do: rdf_data
defp raw_rdf_data(%RDF.Graph{} = rdf_data), do: rdf_data
defp raw_rdf_data(%RDF.Dataset{} = rdf_data), do: rdf_data
defp raw_rdf_data(rdf_data) do
# TODO: find an alternative to Code.eval_quoted
{rdf_data, _} = Code.eval_quoted(rdf_data, [], rdf_data_env())
rdf_data
end
defp ignored_terms!(opts) do
# TODO: find an alternative to Code.eval_quoted - We want to support that the terms can be given as sigils ...
with terms = Keyword.get(opts, :ignore, []) do
{terms, _} = Code.eval_quoted(terms, [], rdf_data_env())
terms
|> Enum.map(fn
term when is_atom(term) -> term
term when is_binary(term) -> String.to_atom(term)
term -> raise RDF.Namespace.InvalidTermError, inspect(term)
end)
|> MapSet.new()
end
end
defp term_mapping!(terms, opts) do
terms =
Map.new(terms, fn
term when is_atom(term) -> {term, true}
term -> {String.to_atom(term), true}
end)
Keyword.get(opts, :alias, [])
|> Enum.reduce(terms, fn {alias, original_term}, terms ->
term = String.to_atom(original_term)
cond do
not valid_characters?(alias) ->
raise RDF.Namespace.InvalidAliasError,
"alias '#{alias}' contains invalid characters"
Map.get(terms, alias) == true ->
raise RDF.Namespace.InvalidAliasError,
"alias '#{alias}' already defined"
strict?(opts) and not Map.has_key?(terms, term) ->
raise RDF.Namespace.InvalidAliasError,
"term '#{original_term}' is not a term in this vocabulary"
Map.get(terms, term, true) != true ->
raise RDF.Namespace.InvalidAliasError,
"'#{original_term}' is already an alias"
true ->
Map.put(terms, alias, to_string(original_term))
end
end)
end
defp aliased_terms(terms) do
terms
|> Map.values()
|> MapSet.new()
|> MapSet.delete(true)
|> Enum.map(&String.to_atom/1)
end
@invalid_terms MapSet.new(~w[
and
or
xor
in
fn
def
defp
defdelegate
defexception
defguard
defguardp
defimpl
defmacro
defmacrop
defmodule
defoverridable
defprotocol
defstruct
function_exported?
macro_exported?
when
if
unless
for
case
with
quote
unquote
unquote_splicing
alias
import
require
super
__aliases__
]a)
def invalid_terms, do: @invalid_terms
defp validate_terms!(terms) do
with aliased_terms = aliased_terms(terms) do
for {term, _} <- terms, term not in aliased_terms and not valid_term?(term) do
term
end
|> handle_invalid_terms!
end
terms
end
defp valid_term?(term), do: term not in @invalid_terms
defp handle_invalid_terms!([]), do: nil
defp handle_invalid_terms!(invalid_terms) do
raise RDF.Namespace.InvalidTermError, """
The following terms can not be used, because they conflict with the Elixir semantics:
- #{Enum.join(invalid_terms, "\n- ")}
You have the following options:
- define an alias with the :alias option on defvocab
- ignore the resource with the :ignore option on defvocab
"""
end
defp validate_characters!(terms, opts) do
if (handling = Keyword.get(opts, :invalid_characters, :fail)) == :ignore do
terms
else
terms
|> detect_invalid_characters
|> handle_invalid_characters(handling, terms)
end
end
defp detect_invalid_characters(terms) do
with aliased_terms = aliased_terms(terms) do
for {term, _} <- terms, term not in aliased_terms and not valid_characters?(term), do: term
end
end
defp handle_invalid_characters([], _, terms), do: terms
defp handle_invalid_characters(invalid_terms, :fail, _) do
raise RDF.Namespace.InvalidTermError, """
The following terms contain invalid characters:
- #{Enum.join(invalid_terms, "\n- ")}
You have the following options:
- if you are in control of the vocabulary, consider renaming the resource
- define an alias with the :alias option on defvocab
- change the handling of invalid characters with the :invalid_characters option on defvocab
- ignore the resource with the :ignore option on defvocab
"""
end
defp handle_invalid_characters(invalid_terms, :warn, terms) do
Enum.each(invalid_terms, fn term ->
IO.warn("'#{term}' is not valid term, since it contains invalid characters")
end)
terms
end
defp valid_characters?(term) when is_atom(term),
do: valid_characters?(Atom.to_string(term))
defp valid_characters?(term),
do: Regex.match?(~r/^[a-zA-Z_]\w*$/, term)
defp validate_case!(terms, nil, _, _), do: terms
defp validate_case!(terms, data, base_iri, opts) do
if (handling = Keyword.get(opts, :case_violations, :warn)) == :ignore do
terms
else
terms
|> detect_case_violations(data, base_iri)
|> group_case_violations
|> handle_case_violations(handling, terms, base_iri, opts)
end
end
defp detect_case_violations(terms, data, base_iri) do
aliased_terms = aliased_terms(terms)
terms
|> Enum.filter(fn {term, _} ->
not (Atom.to_string(term) |> String.starts_with?("_"))
end)
|> Enum.filter(fn
{term, true} ->
if term not in aliased_terms do
improper_case?(term, base_iri, Atom.to_string(term), data)
end
{term, original_term} ->
improper_case?(term, base_iri, original_term, data)
end)
end
defp improper_case?(term, base_iri, iri_suffix, data) do
case ResourceClassifier.property?(term_to_iri(base_iri, iri_suffix), data) do
true -> not downcase?(term)
false -> downcase?(term)
nil -> downcase?(term)
end
end
defp group_case_violations(violations) do
violations
|> Enum.group_by(fn
{term, true} ->
if downcase?(term),
do: :lowercased_term,
else: :capitalized_term
{term, _original} ->
if downcase?(term),
do: :lowercased_alias,
else: :capitalized_alias
end)
end
defp handle_case_violations(%{} = violations, _, terms, _, _) when map_size(violations) == 0,
do: terms
defp handle_case_violations(violations, :fail, _, base_iri, _) do
resource_name_violations = fn violations ->
violations
|> Enum.map(fn {term, true} -> term_to_iri(base_iri, term) end)
|> Enum.map(&to_string/1)
|> Enum.join("\n- ")
end
alias_violations = fn violations ->
violations
|> Enum.map(fn {term, original} ->
"alias #{term} for #{term_to_iri(base_iri, original)}"
end)
|> Enum.join("\n- ")
end
violation_error_lines =
violations
|> Enum.map(fn
{:capitalized_term, violations} ->
"""
Terms for properties should be lowercased, but the following properties are
capitalized:
- #{resource_name_violations.(violations)}
"""
{:lowercased_term, violations} ->
"""
Terms for non-property resource should be capitalized, but the following
non-properties are lowercased:
- #{resource_name_violations.(violations)}
"""
{:capitalized_alias, violations} ->
"""
Terms for properties should be lowercased, but the following aliases for
properties are capitalized:
- #{alias_violations.(violations)}
"""
{:lowercased_alias, violations} ->
"""
Terms for non-property resource should be capitalized, but the following
aliases for non-properties are lowercased:
- #{alias_violations.(violations)}
"""
end)
|> Enum.join()
raise RDF.Namespace.InvalidTermError, """
Case violations detected
#{violation_error_lines}
You have the following options:
- if you are in control of the vocabulary, consider renaming the resource
- define a properly cased alias with the :alias option on defvocab
- change the handling of case violations with the :case_violations option on defvocab
- ignore the resource with the :ignore option on defvocab
"""
end
defp handle_case_violations(violations, :warn, terms, base_iri, _) do
for {type, violations} <- violations,
{term, original} <- violations do
case_violation_warning(type, term, original, base_iri)
end
terms
end
defp case_violation_warning(:capitalized_term, term, _, base_iri) do
IO.warn("'#{term_to_iri(base_iri, term)}' is a capitalized property")
end
defp case_violation_warning(:lowercased_term, term, _, base_iri) do
IO.warn("'#{term_to_iri(base_iri, term)}' is a lowercased non-property resource")
end
defp case_violation_warning(:capitalized_alias, term, _, _) do
IO.warn("capitalized alias '#{term}' for a property")
end
defp case_violation_warning(:lowercased_alias, term, _, _) do
IO.warn("lowercased alias '#{term}' for a non-property resource")
end
defp filename!(opts) do
if filename = Keyword.get(opts, :file) do
cond do
File.exists?(filename) ->
filename
File.exists?(expanded_filename = Path.expand(filename, @vocabs_dir)) ->
expanded_filename
true ->
raise File.Error, path: filename, action: "find", reason: :enoent
end
end
end
defp rdf_data_env do
import RDF.Sigils, warn: false
__ENV__
end
defp rdf_data_vocab_terms(data, base_iri) do
data
|> RDF.Data.resources()
|> Stream.filter(fn
%RDF.IRI{} -> true
_ -> false
end)
|> Stream.map(&to_string/1)
|> Stream.map(&strip_base_iri(&1, base_iri))
|> Stream.filter(&vocab_term?/1)
|> Enum.map(&String.to_atom/1)
end
defp group_terms_by_case(terms) do
terms
|> Enum.group_by(fn {term, _} ->
if downcase?(term),
do: :lowercased,
else: :capitalized
end)
|> Map.new(fn {group, term_mapping} ->
{group, Map.new(term_mapping)}
end)
end
defp strip_base_iri(iri, base_iri) do
if String.starts_with?(iri, base_iri) do
String.replace_prefix(iri, base_iri, "")
end
end
defp vocab_term?(""), do: false
defp vocab_term?(term) when is_binary(term) do
not String.contains?(term, "/")
end
defp vocab_term?(_), do: false
@doc false
@spec term_to_iri(String.t(), String.t() | atom) :: RDF.IRI.t()
def term_to_iri(base_iri, term) when is_atom(term),
do: term_to_iri(base_iri, Atom.to_string(term))
def term_to_iri(base_iri, term),
do: RDF.iri(base_iri <> term)
@doc false
@spec vocabulary_namespace?(module) :: boolean
def vocabulary_namespace?(name) do
case Code.ensure_compiled(name) do
{:module, name} -> function_exported?(name, :__base_iri__, 0)
_ -> false
end
end
end
