Vous ne pouvez pas sélectionner plus de 25 sujets
Les noms de sujets doivent commencer par une lettre ou un nombre, peuvent contenir des tirets ('-') et peuvent comporter jusqu'à 35 caractères.
128 lignes
3.4 KiB
128 lignes
3.4 KiB
%% @doc Built in operators.
|
|
-module(glc_ops).
|
|
|
|
-export([
|
|
lt/2,
|
|
eq/2,
|
|
gt/2,
|
|
wc/1,
|
|
nf/1
|
|
]).
|
|
|
|
-export([
|
|
all/1,
|
|
any/1,
|
|
null/1,
|
|
with/2
|
|
]).
|
|
|
|
-export([
|
|
union/1
|
|
]).
|
|
|
|
-type op() ::
|
|
{atom(), '<', term()} |
|
|
{atom(), '=', term()} |
|
|
{atom(), '>', term()} |
|
|
{atom(), '*'} |
|
|
{atom(), '!'} |
|
|
{any, [op(), ...]} |
|
|
{all, [op(), ...]} |
|
|
{null, true|false}.
|
|
|
|
-export_type([op/0]).
|
|
|
|
%% @doc Test that a field value is less than a term.
|
|
-spec lt(atom(), term()) -> op().
|
|
lt(Key, Term) when is_atom(Key) ->
|
|
{Key, '<', Term};
|
|
lt(Key, Term) ->
|
|
erlang:error(badarg, [Key, Term]).
|
|
|
|
%% @doc Test that a field value is equal to a term.
|
|
-spec eq(atom(), term()) -> op().
|
|
eq(Key, Term) when is_atom(Key) ->
|
|
{Key, '=', Term};
|
|
eq(Key, Term) ->
|
|
erlang:error(badarg, [Key, Term]).
|
|
|
|
%% @doc Test that a field value is greater than a term.
|
|
-spec gt(atom(), term()) -> op().
|
|
gt(Key, Term) when is_atom(Key) ->
|
|
{Key, '>', Term};
|
|
gt(Key, Term) ->
|
|
erlang:error(badarg, [Key, Term]).
|
|
|
|
%% @doc Test that a field exists.
|
|
-spec wc(atom()) -> op().
|
|
wc(Key) when is_atom(Key) ->
|
|
{Key, '*'};
|
|
wc(Key) ->
|
|
erlang:error(badarg, [Key]).
|
|
|
|
%% @doc Test that a field is not found.
|
|
-spec nf(atom()) -> op().
|
|
nf(Key) when is_atom(Key) ->
|
|
{Key, '!'};
|
|
nf(Key) ->
|
|
erlang:error(badarg, [Key]).
|
|
|
|
%% @doc Filter the input using multiple filters.
|
|
%%
|
|
%% For an input to be considered valid output the all filters specified
|
|
%% in the list must hold for the input event. The list is expected to
|
|
%% be a non-empty list. If the list of filters is an empty list a `badarg'
|
|
%% error will be thrown.
|
|
-spec all([op()]) -> op().
|
|
all([_|_]=Conds) ->
|
|
{all, Conds};
|
|
all(Other) ->
|
|
erlang:error(badarg, [Other]).
|
|
|
|
%% @doc Filter the input using one of multiple filters.
|
|
%%
|
|
%% For an input to be considered valid output on of the filters specified
|
|
%% in the list must hold for the input event. The list is expected to be
|
|
%% a non-empty list. If the list of filters is an empty list a `badarg'
|
|
%% error will be thrown.
|
|
-spec any([op()]) -> op().
|
|
any([_|_]=Conds) ->
|
|
{any, Conds};
|
|
any(Other) ->
|
|
erlang:error(badarg, [Other]).
|
|
|
|
|
|
%% @doc Always return `true' or `false'.
|
|
-spec null(boolean()) -> op().
|
|
null(Result) when is_boolean(Result) ->
|
|
{null, Result};
|
|
null(Result) ->
|
|
erlang:error(badarg, [Result]).
|
|
|
|
%% @doc Apply a function to each output of a query.
|
|
%%
|
|
%% Updating the output action of a query finalizes it. Attempting
|
|
%% to use a finalized query to construct a new query will result
|
|
%% in a `badarg' error.
|
|
-spec with(op(), fun((gre:event()) -> term())) -> op().
|
|
with(Query, Fun) when is_function(Fun, 1) ->
|
|
{with, Query, Fun};
|
|
with(Query, Fun) ->
|
|
erlang:error(badarg, [Query, Fun]).
|
|
|
|
%% @doc Return a union of multiple queries.
|
|
%%
|
|
%% The union of multiple queries is the equivalent of executing multiple
|
|
%% queries separately on the same input event. The advantage is that filter
|
|
%% conditions that are common to all or some of the queries only need to
|
|
%% be tested once.
|
|
%%
|
|
%% All queries are expected to be valid and have an output action other
|
|
%% than the default which is `output'. If these expectations don't hold
|
|
%% a `badarg' error will be thrown.
|
|
-spec union([op()]) -> op().
|
|
union(Queries) ->
|
|
case [Query || Query <- Queries, glc_lib:onoutput(Query) =:= output] of
|
|
[] -> {union, Queries};
|
|
[_|_] -> erlang:error(badarg, [Queries])
|
|
end.
|