org.overturetool.vdmj.runtime
Class Context

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<LexNameToken,Value>
          org.overturetool.vdmj.runtime.Context

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map<LexNameToken,Value>

Direct Known Subclasses:

RootContext

public class Context
extends java.util.HashMap<LexNameToken,Value>

A class to hold runtime name/value context information.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry<K,V>, java.util.AbstractMap.SimpleImmutableEntry<K,V>

Field Summary

LexLocation	location The location of the context.
Context	outer A link to a lower level context, if present.
ThreadState	threadState The thread state associated with this context.
java.lang.String	title The name of the location.

Constructor Summary

Context(LexLocation location, java.lang.String title, Context outer)
Create a context at the given location.

Method Summary

Value	check(LexNameToken name) Get the value for a given name.
Context	deepCopy()
protected java.lang.String	format(java.lang.String indent, Context what)
Value	get(java.lang.Object name) Get a name, taking type overloading into account.
int	getDepth()
Context	getFrame(int depth)
Context	getFreeVariables() Get all visible names from this Context, with more visible values overriding those below.
Context	getGlobal() Find the outermost context from this one.
RootContext	getRoot() Find the nearest RootContext in the context chain.
ObjectValue	getSelf()
Context	getUpdateable() Build a new Context based on the current one, but with only the updateable values included (eg.
Value	lookup(LexNameToken name) Return the value of a name, else fail.
void	printStackTrace(java.io.PrintWriter out, boolean variables)
void	put(NameValuePairList nvl) Add a list of name/value pairs to this context.
void	setThreadState(DBGPReader dbgp, CPUValue cpu) Set the current thread state.
java.lang.String	toString()

Methods inherited from class java.util.HashMap

clear, clone, containsKey, containsValue, entrySet, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

equals, hashCode

Field Detail

location

public final LexLocation location

The location of the context.

title

public final java.lang.String title

The name of the location.

outer

public final Context outer

A link to a lower level context, if present.

threadState

public ThreadState threadState

The thread state associated with this context.

Constructor Detail

Context

public Context(LexLocation location,
               java.lang.String title,
               Context outer)

Create a context at the given location.

Parameters:

location -

title -

outer -

Method Detail

setThreadState

public void setThreadState(DBGPReader dbgp,
                           CPUValue cpu)

Set the current thread state. Note this must be called from the thread where the context will run, which may not be where the thread is created. And it must be called before any context chaining is performed.

Parameters:

cpu - TODO

getGlobal

public Context getGlobal()

Find the outermost context from this one.

Returns:

The outermost context.

getRoot

public RootContext getRoot()

Find the nearest RootContext in the context chain.

getUpdateable

public Context getUpdateable()

Build a new Context based on the current one, but with only the updateable values included (eg. "dcl" definitions and state).

deepCopy

public Context deepCopy()

put

public void put(NameValuePairList nvl)

Add a list of name/value pairs to this context.

Parameters:

nvl - A list of name/value pairs.

get

public Value get(java.lang.Object name)

Get a name, taking type overloading into account. If we use the superclass method, different names are considered different, because the map is driven by the names' hashCodes. The equals method of LexNameToken makes a TypeComparator check, which is what we need. But we try a simple super.get() first. TODO Slow though.

Specified by:

get in interface java.util.Map<LexNameToken,Value>

Overrides:

get in class java.util.HashMap<LexNameToken,Value>

getFreeVariables

public Context getFreeVariables()

Get all visible names from this Context, with more visible values overriding those below.

Returns:

A new Context with all visible names.

check

public Value check(LexNameToken name)

Get the value for a given name. This searches outer contexts, if any are present.

Parameters:

name - The name to look for.

Returns:

The value of the name, or null.

lookup

public Value lookup(LexNameToken name)

Return the value of a name, else fail. If the name is not present, a ContextException is thrown.

Parameters:

name - The name to look for.

Returns:

The value of the name.

toString

public java.lang.String toString()

Overrides:

toString in class java.util.AbstractMap<LexNameToken,Value>

format

protected java.lang.String format(java.lang.String indent,
                                  Context what)

printStackTrace

public void printStackTrace(java.io.PrintWriter out,
                            boolean variables)

getDepth

public int getDepth()

getFrame

public Context getFrame(int depth)

getSelf

public ObjectValue getSelf()