org.biojava.utils.bytecode

Class InstructionVector

java.lang.Object

org.biojava.utils.bytecode.InstructionVector

All Implemented Interfaces:

CodeGenerator

public class InstructionVector
extends Object
implements CodeGenerator

A list of Instructions and/or other CodeGenerator objects.

Author:

Thomas Down, Matthew Pocock

Constructor Summary

Constructors

Constructor and Description
InstructionVector()

Method Summary

Methods

Modifier and Type	Method and Description
void	add(CodeGenerator g)
void	add(int pos, CodeGenerator g)
CodeGenerator	generatorAt(int pos)
Label	getEndLabel()
Label	getStartLabel()
void	remove(int pos)
int	size()
int	stackDelta() Return the change in the stack dept this generator will cause.
int	stackDepth() Return the total depth of the stack required by this CodeGenerator.
void	writeCode(CodeContext ctx) Write the byte or bytes for this CodeGenerator to a CodeContext.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

InstructionVector

public InstructionVector()

Method Detail

add

public void add(CodeGenerator g)

size

public int size()

add

public void add(int pos,
       CodeGenerator g)

remove

public void remove(int pos)

generatorAt

public CodeGenerator generatorAt(int pos)

getStartLabel

public Label getStartLabel()

getEndLabel

public Label getEndLabel()

writeCode

public void writeCode(CodeContext ctx)
               throws CodeException

Description copied from interface: CodeGenerator

Write the byte or bytes for this CodeGenerator to a CodeContext.

Specified by:

writeCode in interface CodeGenerator

Parameters:

ctx - a CodeContext to write to

Throws:

CodeException - if there was some failure in writing to the context

stackDepth

public int stackDepth()

Description copied from interface: CodeGenerator

Return the total depth of the stack required by this CodeGenerator.

For single byte-code instructions, this will be the same as stackDelta() if stackDelta() is positive, zero otherwise. For a compound instruction, this will be the maximum stack depth required to execute all sub-instructions.

Specified by:

stackDepth in interface CodeGenerator

Returns:

the stack depth needed

stackDelta

public int stackDelta()

Description copied from interface: CodeGenerator

Return the change in the stack dept this generator will cause.

In the case of an instruction that adds items to the stack, stackDelta will be positive. For instructions that removes items from the stack, this will be negative.

Specified by:

stackDelta in interface CodeGenerator

Returns:

the change between stack depth before and after execution of this code