edu.polytechnique.xvm.exec

Class State

java.lang.Object

edu.polytechnique.xvm.exec.State

public class State
extends java.lang.Object

A representation of the state of the XVM

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	State.Output A representation of output from the interpreter

Field Summary

Fields

Modifier and Type	Field and Description
java.util.List<State.Output>	output The full output of the machine.
int	regFP The frame pointer register (FP)
int	regPC The program counter register (PC)
Word	regR The R register
int	regSP The stack pointer register (SP)
int[]	staticMemory The static memory
int	tick The tick counter (not available to programs)

Constructor Summary

Constructors

Constructor and Description
State() Create a "standard" fresh initial XVM state.

Method Summary

Modifier and Type	Method and Description
Word	getStackEntry(int index) Get an entry from the stack.
void	setOutputHandler(java.util.function.Consumer<java.lang.Integer> outputHandler) Determine how to handle output.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

regR

public Word regR

The R register

regFP

public int regFP

The frame pointer register (FP)

regSP

public int regSP

The stack pointer register (SP)

regPC

public int regPC

The program counter register (PC)

tick

public int tick

The tick counter (not available to programs)

staticMemory

public final int[] staticMemory

The static memory

output

public final java.util.List<State.Output> output

The full output of the machine.

Regardless of whether the output is displayed, all output is stored in this list.

See Also:

setOutputHandler(Consumer)

Constructor Detail

State

public State()

Create a "standard" fresh initial XVM state.

By default, this will have 1024 integers worth of static memory.

Method Detail

getStackEntry

public Word getStackEntry(int index)

Get an entry from the stack.

Parameters:

index - the index of the entry to remove, numbering from bottom (0) to top. 0 <= index < regSP

setOutputHandler

public void setOutputHandler(java.util.function.Consumer<java.lang.Integer> outputHandler)

Determine how to handle output.

By default all output is only stored and not displayed. To allow it to be displayed to the standard output, for example, you can say:

 state.setOutputHandler(System.out::println);
 

Parameters:

outputHandler - the output handler

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object