Module org.cojen.maker

Package org.cojen.maker

Interface MethodMaker

All Superinterfaces:

Maker

public interface MethodMaker
extends Maker

Allows new methods to be defined within a class.

See Also:

• ClassMaker.addMethod(java.lang.Object, java.lang.String, java.lang.Object...)

Method Summary

Modifier and Type	Method	Description
MethodMaker	abstract_()	Switch this method to be abstract.
Field	access(VarHandle handle, Object... values)	Access a VarHandle via a pseudo field.
ClassMaker	addInnerClass(String className)	Add an inner class to this method.
static MethodMaker	begin(MethodHandles.Lookup lookup, Object retType, String name, Object... paramTypes)	Begin defining a standalone method, defined in the same nest as the lookup class.
static MethodMaker	begin(MethodHandles.Lookup lookup, String name, MethodType type)	Begin defining a standalone method, defined in the same nest as the lookup class.
MethodMaker	bridge()	Indicate that this method is a bridge, which implements an inherited method exactly, but it delegates to another method which returns a more specialized return type.
void	catch_(Label tryStart, Object type, Consumer<Variable> handler)	Convenience method which defines an exception handler here.
Variable	catch_(Label tryStart, Label tryEnd, Object type)	Define an exception handler here, which catches exceptions between the given labels.
Variable	catch_(Label tryStart, Label tryEnd, Object... types)	Define an exception handler here, which catches exceptions between the given labels.
Variable	class_()	Returns a variable of type Class which represents the enclosing class of this method.
Variable	concat(Object... values)	Concatenate variables and constants together into a new String in the same matter as the Java concatenation operator.
Field	field(String name)	Access a static or instance field in the enclosing object of this method.
MethodMaker	final_()	Switch this method to be final.
void	finally_(Label tryStart, Runnable handler)	Define a finally handler which is generated for every possible exit path between the start label and here.
MethodHandle	finish()	Finishes the definition of a standalone method.
void	goto_(Label label)	Generates an unconditional goto statement to the given label, which doesn't need to be positioned yet.
Variable	invoke(MethodHandle handle, Object... values)	Invoke a method via a MethodHandle.
Variable	invoke(String name, Object... values)	Invoke a static or instance method on the enclosing object of this method.
void	invokeSuperConstructor(Object... values)	Invoke a super constructor method on the enclosing object of this method, from within a constructor.
void	invokeThisConstructor(Object... values)	Invoke a this constructor method on the enclosing object of this method, from within a constructor.
Label	label()	Returns a new label, initially unpositioned.
void	lineNum(int num)	Define a line number to represent the location of the next code instruction.
String	name()	Returns the name of this method.
MethodMaker	native_()	Switch this method to be native.
Variable	new_(Object type, Object... values)	Allocate a new object.
void	nop()	Append an instruction which does nothing, which can be useful for debugging.
MethodMaker	override()	Verifies that this method overrides an inherited virtual method.
Variable	param(int index)	Returns a variable which accesses a parameter of the method being built.
int	paramCount()	Returns the number of parameters which can be accessed by the param method.
MethodMaker	private_()	Switch this method to be private.
MethodMaker	protected_()	Switch this method to be protected.
MethodMaker	public_()	Switch this method to be public.
void	return_()	Generates a return void statement.
void	return_(Object value)	Generates a statement which returns a variable or a constant.
MethodMaker	signature(Object... components)	Define a signature for this member, which is a string for supporting generic types.
MethodMaker	static_()	Switch this method to be static.
Variable	super_()	Returns a variable which is used for invoking superclass methods.
MethodMaker	synchronized_()	Switch this method to be synchronized.
MethodMaker	synthetic()	Indicate that this method is synthetic.
Variable	this_()	Returns a variable which accesses the enclosing object of this method.
MethodMaker	throws_(Object type)	Declare that this method throws the given exception type.
Variable	var(Object type)	Returns a new uninitialized variable with the given type.
MethodMaker	varargs()	Indicate that this method supports a variable number of arguments.

Methods inherited from interface org.cojen.maker.Maker

addAnnotation, addAttribute, classMaker

Method Details

begin

static MethodMaker begin(MethodHandles.Lookup lookup,
 Object retType,
 String name,
 Object... paramTypes)

Begin defining a standalone method, defined in the same nest as the lookup class.

Parameters:

lookup - define the method using this lookup object

retType - a class or name; can be null if the method returns void

name - method name; use null or "_" if unnamed

paramTypes - classes or names; can be null if the method accepts no parameters

Throws:

IllegalArgumentException - if a type is unsupported

See Also:

• finish()

begin

static MethodMaker begin(MethodHandles.Lookup lookup,
 String name,
 MethodType type)

Begin defining a standalone method, defined in the same nest as the lookup class.

Parameters:

lookup - define the method using this lookup object

name - method name; use null or "_" if unnamed

type - defines the return type and parameter types

See Also:

• finish()

name

String name()

Returns the name of this method.

Specified by:

name in interface Maker

public_

MethodMaker public_()

Switch this method to be public. Methods are package-private by default.

Specified by:

public_ in interface Maker

Returns:

this

private_

MethodMaker private_()

Switch this method to be private. Methods are package-private by default.

Specified by:

private_ in interface Maker

Returns:

this

protected_

MethodMaker protected_()

Switch this method to be protected. Methods are package-private by default.

Specified by:

protected_ in interface Maker

Returns:

this

static_

MethodMaker static_()

Switch this method to be static. Methods are non-static by default.

Specified by:

static_ in interface Maker

Returns:

this

final_

MethodMaker final_()

Switch this method to be final. Methods are non-final by default.

Specified by:

final_ in interface Maker

Returns:

this

synchronized_

MethodMaker synchronized_()

Switch this method to be synchronized. Methods are non-synchronized by default.

Returns:

this

abstract_

MethodMaker abstract_()

Switch this method to be abstract. Methods are non-abstract by default.

Returns:

this

native_

MethodMaker native_()

Switch this method to be native. Methods are non-native by default.

Returns:

this

synthetic

MethodMaker synthetic()

Indicate that this method is synthetic. Methods are non-synthetic by default.

Specified by:

synthetic in interface Maker

Returns:

this

bridge

MethodMaker bridge()

Indicate that this method is a bridge, which implements an inherited method exactly, but it delegates to another method which returns a more specialized return type.

Returns:

this

varargs

MethodMaker varargs()

Indicate that this method supports a variable number of arguments.

Returns:

this

Throws:

IllegalStateException - if last parameter type isn't an array

throws_

MethodMaker throws_(Object type)

Declare that this method throws the given exception type.

Parameters:

type - a class or class name

Returns:

this

Throws:

IllegalArgumentException - if the type is unsupported

override

MethodMaker override()

Verifies that this method overrides an inherited virtual method.

Returns:

this

Throws:

IllegalStateException - if not overriding an inherited virtual method, or if the inherited method is final

signature

MethodMaker signature(Object... components)

Define a signature for this member, which is a string for supporting generic types. The components can be strings or types (class, ClassMaker, etc.), which are concatenated into a single string. Consult the JVM specification for the signature syntax.

Specified by:

signature in interface Maker

Returns:

this

class_

Variable class_()

Returns a variable of type Class which represents the enclosing class of this method.

See Also:

• Maker.classMaker()

this_

Variable this_()

Returns a variable which accesses the enclosing object of this method.

Throws:

IllegalStateException - if making a static method

super_

Variable super_()

Returns a variable which is used for invoking superclass methods. The type of the variable is the superclass, and when applicable, the instance is this_.

param

Variable param(int index)

Returns a variable which accesses a parameter of the method being built.

Parameters:

index - zero based index

Throws:

IndexOutOfBoundsException - if index is out of bounds

paramCount

int paramCount()

Returns the number of parameters which can be accessed by the param method.

var

Variable var(Object type)

Returns a new uninitialized variable with the given type. Call set to initialize it immediately.

Parameters:

type - a class, class name, or a variable

Throws:

IllegalArgumentException - if the type is unsupported

lineNum

void lineNum(int num)

Define a line number to represent the location of the next code instruction.

label

Label label()

Returns a new label, initially unpositioned. Call here to position it immediately.

goto_

void goto_(Label label)

Generates an unconditional goto statement to the given label, which doesn't need to be positioned yet.

See Also:

• Label.goto_()

return_

void return_()

Generates a return void statement.

Throws:

IllegalStateException - if this method cannot return void

return_

void return_(Object value)

Generates a statement which returns a variable or a constant.

Parameters:

value - Variable or constant

Throws:

IllegalArgumentException - if the value isn't a variable or a supported constant

IllegalStateException - if this method must return void

field

Field field(String name)

Access a static or instance field in the enclosing object of this method.

Parameters:

name - field name

Throws:

IllegalStateException - if the field isn't found

invoke

Variable invoke(String name,
 Object... values)

Invoke a static or instance method on the enclosing object of this method.

Parameters:

name - the method name enclosing class

values - Variables or constants

Returns:

the result of the method, which is null if void

Throws:

IllegalArgumentException - if a value isn't a variable or a supported constant

IllegalStateException - if the method isn't found

See Also:

• Variable.invoke

invokeSuperConstructor

void invokeSuperConstructor(Object... values)

Invoke a super constructor method on the enclosing object of this method, from within a constructor.

Parameters:

values - Variables or constants

Throws:

IllegalArgumentException - if a value isn't a variable or a supported constant

IllegalStateException - if not defining a constructor, or if a matching constructor isn't found

invokeThisConstructor

void invokeThisConstructor(Object... values)

Invoke a this constructor method on the enclosing object of this method, from within a constructor.

Parameters:

values - Variables or constants

Throws:

IllegalArgumentException - if a value isn't a variable or a supported constant

IllegalStateException - if not defining a constructor, or if a matching constructor isn't found

invoke

Variable invoke(MethodHandle handle,
 Object... values)

Invoke a method via a MethodHandle. If making a class to be loaded externally, the handle must be truly Constable.

Parameters:

handle - runtime method handle

values - Variables or constants

Returns:

the result of the method, which is null if void

Throws:

IllegalArgumentException - if a value isn't a variable or a supported constant

IllegalStateException - if defining an external class and the handle isn't truly Constable

new_

Variable new_(Object type,
 Object... values)

Allocate a new object. If the type is an ordinary object, a matching constructor is invoked. If the type is an array, then no constructor is invoked, and the given values represent array dimension sizes.

Parameters:

type - class name or Class instance

values - Variables or constants

Returns:

the new object

Throws:

IllegalArgumentException - if the type is unsupported, or if a value isn't a variable or a supported constant

IllegalStateException - if the constructor isn't found

catch_

Variable catch_(Label tryStart,
 Label tryEnd,
 Object type)

Define an exception handler here, which catches exceptions between the given labels. Any code prior to the handler must not flow into it directly.

Parameters:

type - exception type to catch; pass null to catch anything

Returns:

a variable which references the exception instance

Throws:

IllegalArgumentException - if the type is unsupported

IllegalStateException - if the start label is unpositioned

catch_

Variable catch_(Label tryStart,
 Label tryEnd,
 Object... types)

Define an exception handler here, which catches exceptions between the given labels. Any code prior to the handler must not flow into it directly. This variant supports matching on multiple exception types, and the effective exception type is the nearest common superclass.

Parameters:

types - exception types to catch; pass null to catch anything

Returns:

a variable which references the exception instance

Throws:

IllegalArgumentException - if a type is unsupported, or if no types are given

IllegalStateException - if the start label is unpositioned

catch_

void catch_(Label tryStart,
 Object type,
 Consumer<Variable> handler)

Convenience method which defines an exception handler here. Code prior to the handler flows around it.

Parameters:

type - exception type to catch; pass null to catch anything

handler - receives a variable which references the exception instance

Throws:

IllegalArgumentException - if the type is unsupported

IllegalStateException - if the start label is unpositioned

finally_

void finally_(Label tryStart,
 Runnable handler)

Define a finally handler which is generated for every possible exit path between the start label and here.

Parameters:

handler - called for each exit path to generate handler code

Throws:

IllegalStateException - if the start label is unpositioned

concat

Variable concat(Object... values)

Concatenate variables and constants together into a new String in the same matter as the Java concatenation operator. If no values are given, the returned variable will refer to the empty string.

Parameters:

values - Variables or constants

Returns:

the result in a new String variable

Throws:

IllegalArgumentException - if a value isn't a variable or a supported constant

access

Field access(VarHandle handle,
 Object... values)

Access a VarHandle via a pseudo field. If making a class to be loaded externally, the handle must be truly Constable.

All of the coordinate values must be provided up front, which are then used each time the VarHandle is accessed. Variable coordinates are read each time the access field is used — they aren't fixed to the initial value. In addition, the array of coordinate values isn't cloned, permitting changes without needing to obtain a new access field.

A VarHandle can also be accessed by calling toMethodHandle, which is then passed to the invoke method.

Parameters:

handle - runtime variable handle

values - Variables or constants for each coordinate

Returns:

a pseudo field which accesses the variable

Throws:

IllegalArgumentException - if a value isn't a variable or a supported constant, or if the number of values doesn't match the number of coordinates

IllegalStateException - if defining an external class and the handle isn't truly Constable

nop

void nop()

Append an instruction which does nothing, which can be useful for debugging.

addInnerClass

ClassMaker addInnerClass(String className)

Add an inner class to this method. The actual class name will have a suitable suffix applied to ensure uniqueness. The inner class doesn't have access to the local variables of the enclosing method, and so they must be passed along explicitly.

The returned ClassMaker instance isn't attached to this maker, and so it can be acted upon by a different thread.

Parameters:

className - simple class name; pass null to use default

Throws:

IllegalArgumentException - if not given a simple class name

IllegalStateException - if the enclosing class or method is finished

finish

MethodHandle finish()

Finishes the definition of a standalone method.

Throws:

IllegalStateException - if already finished or if not a standalone method

See Also:

• begin(java.lang.invoke.MethodHandles.Lookup, java.lang.Object, java.lang.String, java.lang.Object...)