Built-in functions

Concept functions

iid(x): Returns the internal ID of the provided instance argument as a string. The result is intended to be used in an iid predicate in future queries to uniquely identify the instance. iid() is mainly intended for use in fetch queries to uniquely identify the instance. It is not typically needed in other query types, as the IID is available directly in the result rows.

iid($x) == "0x1e0000000000000000001f"

label($x) == "person"

get_doc(t): Returns the documentation string of the provided type argument.
If the type has no @doc annotation, an empty string is returned.

get_doc(person) == "This represents a person"

get_owns_doc(owner, attribute): Returns the documentation string of the provided owns if it exists.
If the owns exists but has no @doc annotation, an empty string is returned.

get_owns_doc(person, name) == "The full legal name of the person"

get_plays_doc(player, role): Returns the documentation string of the provided plays if it exists.
If the plays exists but has no @doc annotation, an empty string is returned.

get_plays_doc(person, friendship:friend) == "A person can be a friend"

get_relates_doc(relation, role): Returns the documentation string of the provided relates if it exists.
If the relates exists but has no @doc annotation, an empty string is returned.

get_relates_doc(friendship, friendship:friend) == "A party in this friendship"

get_sub_doc(sub, sup): Returns the documentation string of the provided sub if it exists.
If the sub exists but has no @doc annotation, an empty string is returned.

get_sub_doc(student, person) == "A person who is a student"

get_fun_doc(function_name): Returns the documentation string of the provided function if it exists.
If the function exists but has no @doc annotation, an empty string is returned.

get_fun_doc("my_function") == "This is my custom function"

get_struct_doc(struct_name): Returns the documentation string of the provided struct if it exists.
If the struct exists but has no @doc annotation, an empty string is returned.

get_struct_doc("my_struct") == "This is my custom struct"

get_struct_field_doc(struct_name, field_name): Returns the documentation string of the provided struct field if it exists.
If the struct field exists but has no @doc annotation, an empty string is returned.

get_struct_field_doc("my_struct", "its_field") == "This is a field of my custom struct"

get_meta(key, t): Returns the metadata of the provided type with the specified key.
If the type has no @meta annotation with the specified key, an empty string is returned.

get_meta("icon", person) == ":silhouette.png"

get_all_meta(t): Returns all metadata of the provided type as a stream of key-value pairs.

let $key, $value in get_all_meta(person);

$key == "icon"
$value == ":silhouette.png"

get_owns_meta(key, owner, attribute): Returns the metadata of the provided owns with the specified key, if it exists.
If the owns exists but has no @meta annotation with the specified key, an empty string is returned.

get_owns_meta("color", person, name) == "#0088FF"

get_owns_all_meta(owner, attribute): Returns all metadata of the provided owns as a stream of key-value pairs, if it exists.

let $key, $value in get_all_owns_meta(person, name);

$key == "color"
$value == "#0088FF"

get_plays_meta(key, player, role): Returns the metadata of the provided plays with the specified key, if it exists.
If the plays exists but has no @meta annotation with the specified key, an empty string is returned.

get_plays_meta("color", person, friendship:friend) == "#00CC00"

get_plays_all_meta(player, role): Returns all metadata of the provided plays as a stream of key-value pairs, if it exists.

let $key, $value in get_plays_all_meta(person, friendship:friend);

$key == "color"
$value == "#00CC00"

get_relates_meta(key, relation, role): Returns the metadata of the provided relates with the specified key, if it exists.
If the relates exists but has no @meta annotation with the specified key, an empty string is returned.

get_relates_meta("color", friendship, friendship:friend) == "#0088FF"

get_relates_all_meta(relation, role): Returns all metadata of the provided relates as a stream of key-value pairs, if it exists.

let $key, $value in get_relates_all_meta(friendship, friendship:friend);

$key == "color"
$value == "#0088FF"

get_sub_meta(key, sub, sup): Returns the metadata of the provided sub with the specified key, if it exists.
If the sub exists but has no @meta annotation with the specified key, an empty string is returned.

get_sub_meta("arrow-style", student, person) == "dashed"

get_sub_all_meta(sub, sup): Returns all metadata of the provided sub as a stream of key-value pairs, if it exists.

let $key, $value in get_sub_all_meta(student, person);

$key == "arrow-style"
$value == "dashed"

get_fun_meta(key, function_name): Returns the metadata of the provided function with the specified key, if it exists.
If the function exists but has no @meta annotation with the specified key, an empty string is returned.

get_fun_meta("category", "my_function") == "utility"

get_fun_all_meta(function_name): Returns all metadata of the provided function as a stream of key-value pairs, if it exists.

let $key, $value in get_fun_all_meta("my_function");

$key == "category"
$value == "utility"

get_struct_meta(key, struct_name): Returns the metadata of the provided struct with the specified key, if it exists.
If the struct exists but has no @meta annotation with the specified key, an empty string is returned.

get_struct_meta("version", "my_struct") == "1.0"

get_struct_all_meta(struct_name): Returns all metadata of the provided struct as a stream of key-value pairs, if it exists.

let $key, $value in get_struct_all_meta("my_struct");

$key == "version"
$value == "1.0"

get_struct_field_meta(key, struct_name, field_name): Returns the metadata of the provided struct field with the specified key, if it exists.
If the struct field exists but has no @meta annotation with the specified key, an empty string is returned.

get_struct_field_meta("description", "my_struct", "its_field") == "A field description"

get_struct_field_all_meta(struct_name, field_name): Returns all metadata of the provided struct field as a stream of key-value pairs, if it exists.

let $key, $value in get_struct_field_all_meta("my_struct", "its_field");

$key == "description"
$value == "A field description"