org.biojava.utils.bytecode
Class InstructionVector

java.lang.Object
  extended by org.biojava.utils.bytecode.InstructionVector
All Implemented Interfaces:
CodeGenerator

public class InstructionVector
extends java.lang.Object
implements CodeGenerator

A list of Instructions and/or other CodeGenerator objects.

Author:
Thomas Down, Matthew Pocock

Constructor Summary
InstructionVector()
           
 
Method Summary
 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