org.deri.iris.compiler
Class BuiltinRegister

java.lang.Object
  org.deri.iris.compiler.BuiltinRegister

public final class BuiltinRegister
extends Object

Holds the registry of built-in atoms that the parser can use to translate predicates to built-ins as the logic program is parsed.

Before a built-in can be recognized by the parser it must first be registered with the associated BuiltinRegister. The BuiltinRegister uses instances of the built-ins to get their predicate names and their class instances. The BuiltinRegister basically holds a map between predicate symbol and class instance. This class initialises itself with all the standard IRIS built-ins.

To add more, simply call registerBuiltin() with an instance of the new built-in type.

To unregister a built-in call unregisterBuiltin(). However, beware that unregistering any of the standard built-ins can lead to undefined behaviour.

Constructor Summary

BuiltinRegister()
Constructs a new built-in register and register all the standard IRIS built-ins.

Method Summary

boolean	equals(Object o)
int	getBuiltinArity(String s) Returns the arity of a registered built-in.
Class<?>	getBuiltinClass(String s) Returns the class of a registered built-in.
int	hashCode()
void	registerBuiltin(IBuiltinAtom builtin) Registers a single built-in.
String	toString() Returns a short description of this object.
void	unregisterBuiltin(IBuiltinAtom builtin) De-registers a single built-in.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BuiltinRegister

public BuiltinRegister()

Constructs a new built-in register and register all the standard IRIS built-ins.

Method Detail

registerBuiltin

public void registerBuiltin(IBuiltinAtom builtin)

Registers a single built-in. Already registered built-ins will be overwritten.

Parameters:

builtin - an instance of the built-in to register

Throws:

IllegalArgumentException - if the class is null

unregisterBuiltin

public void unregisterBuiltin(IBuiltinAtom builtin)

De-registers a single built-in.

Parameters:

builtin - an instance of the built-in to de-register

Throws:

IllegalArgumentException - if the class is null

getBuiltinArity

public int getBuiltinArity(String s)

Returns the arity of a registered built-in.

Parameters:

s - the name (predicate symbol) of the built-in

Returns:

the arity, or -1 if such a built-in hasn't been registered yet

getBuiltinClass

public Class<?> getBuiltinClass(String s)

Returns the class of a registered built-in.

Parameters:

s - the name (predicate symbol) of the built-in

Returns:

the class, or null if such a built-in hasn't been registered yet

toString

public String toString()

Returns a short description of this object. The format of the returned string is undocumented and subject to change.

An example return string could be: [ADD[3, org.deri.iris.builtins.AddBuiltin],SUBTRACT[3, org.deri.builtins.SubtractBuiltin]]

Overrides:

toString in class Object

Returns:

the description

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object