rego Namespace Reference

Namespaces
namespace	bundle

Classes
class	BigInt
	Big Integer implemention based on strings. More...
struct	BuiltInDef
	Struct which defines a built-in function. More...
class	BuiltInsDef
	Manages the set of builtins used by an interpreter to resolve built-in calls. More...
struct	BundleDef
	Represents a compiled Rego bundle. More...
class	Interpreter
	This class forms the main interface to the Rego library. More...
class	Output
	Encapsulates the output of a Rego query. More...
class	UnwrapOpt
	Options for unwrapping an argument. More...
struct	UnwrapResult
	Result of unwrapping a node. More...
class	VirtualMachine
	This class implements a virtual machine that can execute compiled Rego bundles. More...

Typedefs
using	BuiltIn = std::shared_ptr< BuiltInDef >
	A pointer to a BuiltInDef.
using	BuiltInBehavior = std::function< Node(const Nodes &)>
	The function pointer to the behavior of the built-in.
typedef BuiltIn(*	BuiltInFactory) ()
typedef std::shared_ptr< BundleDef >	Bundle
	A pointer to a BundleDef.

Enumerations
enum class	SetFormat { Angle , Square , Rego }
	Controls how sets are rendered by to_key(). More...
enum class	LogLevel : regoEnum {   None = REGO_LOG_LEVEL_NONE , Error = REGO_LOG_LEVEL_ERROR , Output = REGO_LOG_LEVEL_OUTPUT , Warn = REGO_LOG_LEVEL_WARN ,   Info = REGO_LOG_LEVEL_INFO , Debug = REGO_LOG_LEVEL_DEBUG , Trace = REGO_LOG_LEVEL_TRACE }
	The logging level.

Functions
Node	unwrap_arg (const Nodes &args, const UnwrapOpt &options)
	Unwraps an argument from the provided vector of nodes.
UnwrapResult	unwrap (const Node &term, const Token &type)
	Attempts to unwrap a node to a specified type.
UnwrapResult	unwrap (const Node &term, const std::set< Token > &types)
	Attempts to unwrap an argument to a specified type.
BigInt	get_int (const Node &node)
	Extracts the value of a node as an integer.
std::optional< BigInt >	try_get_int (const Node &node)
	Attempts to extract the value of a node as an integer. In the case that the node is a double, it will check if the double is integral, i.e. 5.0 will be considered the integer 5.
double	get_double (const Node &node)
	Extracts the value of a node as an double.
std::optional< double >	try_get_double (const Node &node)
	Attempts to extract the value of a node as an 64-bit floating point number.
std::string	get_string (const Node &node)
	Extracts the value of a node as a string.
std::optional< std::string >	try_get_string (const Node &node)
	Attempts to extract the value of a node as a string.
bool	get_bool (const Node &node)
	Extracts the value of a node as a boolean.
std::optional< bool >	try_get_bool (const Node &node)
	Attempts to extract the value of a node as a boolean.
std::optional< Node >	try_get_item (const Node &node, const std::string_view &key)
	Tries to get an item within an object using its key.
std::string_view	get_raw_string (const Node &node)
	Returns the raw location of the node from the source.
Node	scalar (BigInt value)
	Converts the value to a scalar node.
Node	scalar (double value)
	Converts the value to a scalar node.
Node	scalar (bool value)
	Converts the value to a scalar node.
Node	scalar (const char *value)
	Converts the value to a scalar node.
Node	scalar (const std::string &value)
	Converts the value to a scalar node.
Node	scalar ()
	Creates a null scalar.
Node	number (double value)
	Converts the value to a scalar node.
Node	boolean (bool value)
	Converts the value to a scalar node.
Node	string (const char *value)
	Converts the value to a scalar node.
Node	string (const std::string &value)
	Converts the value to a scalar node.
Node	null ()
	Creates a null scalar.
Node	object_item (const Node &key_term, const Node &val_term)
	Converts the key and val terms to an object item.
Node	object (const std::initializer_list< Node > &object_items)
	Converts the value to an object node.
Node	array (const std::initializer_list< Node > &array_members)
	Converts the value to an array node.
Node	set (const std::initializer_list< Node > &set_members)
	Converts the value to a set node.
Node	err (NodeRange &r, const std::string &msg, const std::string &code=UnknownError)
	Generates an error node.
Node	err (Node node, const std::string &msg, const std::string &code=UnknownError)
	Generates an error node.
Node	version ()
	Returns a node representing the version of the library.
std::string	to_key (const trieste::Node &node, SetFormat set_format=SetFormat::Angle, bool sort_arrays=false, const char *list_delim=",")
	Converts a node to a unique key representation that can be used for comparison.
LogLevel	log_level_from_string (const std::string &value)
	Converts a string to a log level (case insensitive).
Reader	file_to_rego ()
	Parses Rego queries and virtual documents.
Rewriter	rego_to_input ()
	Rewrites a Query AST to an input term.
Rewriter	json_to_rego (bool as_term=false)
	Rewrites a JSON AST to a Rego data input AST.
Rewriter	rego_to_json ()
	Rewrites a Rego binding term to a JSON AST.
Rewriter	rego_to_yaml ()
	Rewrites a Rego binding term to a YAML AST.
Rewriter	json_to_bundle ()
	Rewrites an OPA bundle JSON to a Bundle AST.
Rewriter	bundle_to_json ()
	Rewrites a Bundle AST to a JSON AST in OPA bundle JSON format.
Rewriter	rego_to_bundle (BuiltIns builtins=BuiltInsDef::create())
	Rewrites a Rego AST to a Bundle AST.

Detailed Description

This namespace provides the C++ API for the library. It includes all the token types for nodes in the AST, the well-formedness definitions for each pass, the built-in system and custom types for handling various kinds of data (e.g. the BigInt class).

Enumeration Type Documentation

SetFormat

enum class rego::SetFormat

strong

Controls how sets are rendered by to_key().

Enumerator
Angle	Angle brackets: <1, 2, 3> (internal key representation).
Square	Square brackets: [1, 2, 3] (JSON-compatible array format).
Rego	Curly braces / set(): {1, 2, 3} or set() (OPA Rego display format).

Function Documentation

array()

Node rego::array

(

const std::initializer_list< Node > &

array_members

)

Converts the value to an array node.

Parameters

array_members

The members of the array.

Returns

The array node (array (term) (term) ...)

boolean()

Node rego::boolean

(

bool

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Returns

The scalar node (scalar (TRUE|FALSE)))

err() [1/2]

Node rego::err	(	Node	node,
		const std::string &	msg,
		const std::string &	code = UnknownError
	)

Generates an error node.

Parameters

node	The node for which the error occurred.
msg	The error message.
code	The error code.

Returns

The generated error node.

err() [2/2]

Node rego::err	(	NodeRange &	r,
		const std::string &	msg,
		const std::string &	code = UnknownError
	)

Generates an error node.

Parameters

r	The range of nodes over which the error occurred.
msg	The error message.
code	The error code.

Returns

The generated error node.

file_to_rego()

Reader rego::file_to_rego

(

)

Parses Rego queries and virtual documents.

Bundle

get_bool()

bool rego::get_bool

(

const Node &

node

)

Extracts the value of a node as a boolean.

Parameters

node	The node to extract from.

Returns

The boolean value of the node.

get_double()

double rego::get_double

(

const Node &

node

)

Extracts the value of a node as an double.

Parameters

node	The node to extract from.

Returns

The double value of the node.

get_int()

BigInt rego::get_int

(

const Node &

node

)

Extracts the value of a node as an integer.

Parameters

node	The node to extract from.

Returns

The integer value of the node.

get_raw_string()

std::string_view rego::get_raw_string

(

const Node &

node

)

Returns the raw location of the node from the source.

Note

If this is a synthetic node (i.e., one generated by the compiler) then this may be an empty string.

Parameters

node

Returns

The raw string from the original source for this Node

get_string()

std::string rego::get_string

(

const Node &

node

)

Extracts the value of a node as a string.

The resulting string will have any enclosing quotes removed.

Parameters

node	The node to extract from.

Returns

The string value of the node.

log_level_from_string()

LogLevel rego::log_level_from_string

(

const std::string &

value

)

Converts a string to a log level (case insensitive).

Parameters

value

One of Error, Warn, Output, Info, Debug, Trace.

Returns

the corresponding log level, or LogLevel::Unsupported.

null()

Node rego::null

(

)

Creates a null scalar.

Returns

The scalar node (scalar (NULL)))

number()

Node rego::number

(

double

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Returns

The scalar node (scalar (FLOAT

)))

object()

Node rego::object

(

const std::initializer_list< Node > &

object_items

)

Converts the value to an object node.

Parameters

object_items

The object items of the object.

Returns

The object node (object (object_item) (object_item) ...)

object_item()

Node rego::object_item	(	const Node &	key_term,
		const Node &	val_term
	)

Converts the key and val terms to an object item.

Parameters

key_term	The key term.
val_term	The value term.

Returns

The object item node (object_item (key_term) (val_term))

scalar() [1/6]

Node rego::scalar

(

)

Creates a null scalar.

Deprecated:

Use null() instead

Returns

The scalar node (scalar (NULL)))

scalar() [2/6]

Node rego::scalar

(

BigInt

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Deprecated:

Use number() instead

Returns

The scalar node (scalar (INT

)))

scalar() [3/6]

Node rego::scalar

(

bool

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Deprecated:

Use boolean() instead

Returns

The scalar node (scalar (TRUE|FALSE)))

scalar() [4/6]

Node rego::scalar

(

const char *

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Deprecated:

Use string() instead

Returns

The scalar node (scalar (STRING

)))

scalar() [5/6]

Node rego::scalar

(

const std::string &

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Deprecated:

Use string() instead

Returns

The scalar node (scalar (STRING

)))

scalar() [6/6]

Node rego::scalar

(

double

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Deprecated:

Use number() instead

Returns

The scalar node (scalar (FLOAT

)))

set()

Node rego::set

(

const std::initializer_list< Node > &

set_members

)

Converts the value to a set node.

Parameters

set_members

The members of the set.

Returns

The set node (set (term) (term) ...)

string() [1/2]

Node rego::string

(

const char *

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Returns

The scalar node (scalar (STRING

)))

string() [2/2]

Node rego::string

(

const std::string &

value

)

Converts the value to a scalar node.

Parameters

value

The value to convert.

Returns

The scalar node (scalar (STRING

)))

to_key()

std::string rego::to_key	(	const trieste::Node &	node,
		SetFormat	set_format = SetFormat::Angle,
		bool	sort_arrays = false,
		const char *	list_delim = ","
	)

Converts a node to a unique key representation that can be used for comparison.

Parameters

node	The node to convert.
set_format	How to render set values.
sort_arrays	Whether to sort array elements.
list_delim	The delimiter to use when joining array elements.

Returns

The key representation of the node.

try_get_bool()

std::optional< bool > rego::try_get_bool

(

const Node &

node

)

Attempts to extract the value of a node as a boolean.

Parameters

node	The node to extract from.

Returns

The boolean value of the node.

try_get_double()

std::optional< double > rego::try_get_double

(

const Node &

node

)

Attempts to extract the value of a node as an 64-bit floating point number.

Parameters

node	The node to extract from.

Returns

The float value of the node

try_get_int()

std::optional< BigInt > rego::try_get_int

(

const Node &

node

)

Attempts to extract the value of a node as an integer. In the case that the node is a double, it will check if the double is integral, i.e. 5.0 will be considered the integer 5.

Parameters

node	The node to extract from.

Returns

The integer value of the node

try_get_item()

std::optional< Node > rego::try_get_item	(	const Node &	node,
		const std::string_view &	key
	)

Tries to get an item within an object using its key.

Parameters

node	The object to search.
key	The key to search for.

Returns

The item node if found, otherwise std::nullopt.

try_get_string()

std::optional< std::string > rego::try_get_string

(

const Node &

node

)

Attempts to extract the value of a node as a string.

The resulting string will have any enclosing quotes removed.

Parameters

node	The node to extract from.

Returns

The string value of the node

unwrap() [1/2]

UnwrapResult rego::unwrap	(	const Node &	term,
		const std::set< Token > &	types
	)

Attempts to unwrap an argument to a specified type.

Parameters

term	The term to unwrap.
types	The acceptable types.

Returns

An unwrap result or an appropriate error node.

unwrap() [2/2]

UnwrapResult rego::unwrap	(	const Node &	term,
		const Token &	type
	)

Attempts to unwrap a node to a specified type.

Parameters

term	The term to unwrap.
type	The acceptable type.

Returns

An unwrap result or an appropriate error node.

unwrap_arg()

Node rego::unwrap_arg	(	const Nodes &	args,
		const UnwrapOpt &	options
	)

Unwraps an argument from the provided vector of nodes.

Parameters

args	The vector of nodes to unwrap from.
options	The options for unwrapping.

Returns

The unwrapped argument or an appropriate error node.

version()

Node rego::version

(

)

Returns a node representing the version of the library.

The resulting node will be an object containing:

• The Git commit hash ("commit")
• The library version ("regocpp_version")
• The supported OPA Rego version ("version")
• The environment variables ("env")