gnu.mapping

Class CallContext

public class CallContext extends Object

A procedure activation stack (when compiled with explicit stacks).

Field Summary
static int	ARG_IN_IVALUE1
static int	ARG_IN_IVALUE2
static int	ARG_IN_VALUE1
static int	ARG_IN_VALUE2
static int	ARG_IN_VALUE3
static int	ARG_IN_VALUE4
static int	ARG_IN_VALUES_ARRAY
Consumer	consumer Function results are written to this Consumer.
int	count Number of actual arguments.
Object[][]	evalFrames Current stack of evaluation frames for interpreter.
int	ivalue1
int	ivalue2
int	next Index of next argument.
int	pc The program location in the current procedure.
Procedure	proc
Object	value1 Used for passing parameters.
Object	value2
Object	value3
Object	value4
Object[]	values
ValueStack	vstack Default place for function results.
int	where Encoding of where the arguments are.

Method Summary
void	cleanupFromContext(int oldIndex) Cleanup-only part of getFromContext.
Object[]	getArgs()
Environment	getEnvironment()
Environment	getEnvironmentRaw()
Object	getFromContext(int oldIndex) Routine to extract result and restore state after startFromContext.
static CallContext	getInstance() Get or create a CallContext for the current thread.
Object	getNextArg() Get the next incoming argument.
Object	getNextArg(Object defaultValue) Get the next incoming argument.
int	getNextIntArg()
int	getNextIntArg(int defaultValue)
static CallContext	getOnlyInstance() Get but don't create a CallContext for the current thread.
Object[]	getRestArgsArray(int next) Get remaining arguments as an array.
LList	getRestArgsList(int next) Get remaining arguments as a list.
void	lastArg() Note that we are done with the input arguments.
void	popFluid()
void	pushFluid(Location loc)
void	runUntilDone()
Object	runUntilValue() Run until no more continuations, returning final result.
void	runUntilValue(Consumer out) Run until no more continuations, sending result to a COnsumer.
void	setEnvironmentRaw(Environment env)
static void	setInstance(CallContext ctx)
int	startFromContext() Setup routine before calling a method that takes a CallContext.
void	writeValue(Object value) Write values (of function result) to current consumer.

Field Detail

ARG_IN_VALUES_ARRAY

public static final int ARG_IN_VALUES_ARRAY

consumer

public Consumer consumer

Function results are written to this Consumer. This may point to vstack - or some other Consumer.

count

public int count

Number of actual arguments.

evalFrames

public Object[][] evalFrames

Current stack of evaluation frames for interpreter.

ivalue2

public int ivalue2

public int next

Index of next argument. This is used by methods like getNextArg, used by callees.

pc

public int pc

The program location in the current procedure. This a selector that only has meaning to the proc's Procedure.

value1

public Object value1

Used for passing parameters. (Will be replaced by vstack.)

vstack

public ValueStack vstack

Default place for function results. In the future, function arguments will also use vstack.

where

public int where

Encoding of where the arguments are. Each argument uses 4 bits. Arguments beyond 8 are implicitly ARG_IN_VALUES_ARRAY.

Method Detail

cleanupFromContext

public final void cleanupFromContext(int oldIndex)

Cleanup-only part of getFromContext. This can be in an exception handler as an alternative to getFromContext, which is called in the non-exception case. (Alternatively, the compiler could call cleanupFromContext from a finally clause but that is less efficient, partly because the JVM stack must be empty before a finally subroutine.)

getArgs

public Object[] getArgs()

getEnvironment

public final Environment getEnvironment()

getEnvironmentRaw

public final Environment getEnvironmentRaw()

getFromContext

public final Object getFromContext(int oldIndex)

Routine to extract result and restore state after startFromContext.

getInstance

public static CallContext getInstance()

Get or create a CallContext for the current thread.

getNextArg

public Object getNextArg()

Get the next incoming argument. Throw WrongArguments if there are no more arguments. FIXME: This and following methods don't really fit until the current match/apply-based API, at least as currently implemented. We probably need to pass in (or make this a method of) the Procedure.

getNextArg

public Object getNextArg(Object defaultValue)

Get the next incoming argument. Return defaultValue if there are no more arguments.

getNextIntArg

public int getNextIntArg()

getNextIntArg

public int getNextIntArg(int defaultValue)

getOnlyInstance

public static CallContext getOnlyInstance()

Get but don't create a CallContext for the current thread.

getRestArgsArray

public final Object[] getRestArgsArray(int next)

Get remaining arguments as an array.

getRestArgsList

public final LList getRestArgsList(int next)

Get remaining arguments as a list. Used for Scheme and Lisp rest args.

lastArg

public void lastArg()

Note that we are done with the input arguments. Throw WrongArguments if there are unprocessed arguments.

popFluid

public final void popFluid()

pushFluid

public final void pushFluid(Location loc)

runUntilDone

public void runUntilDone()

runUntilValue

public final Object runUntilValue()

Run until no more continuations, returning final result.

runUntilValue

public final void runUntilValue(Consumer out)

Run until no more continuations, sending result to a COnsumer.

setEnvironmentRaw

public final void setEnvironmentRaw(Environment env)

setInstance

public static void setInstance(CallContext ctx)

startFromContext

public final int startFromContext()

Setup routine before calling a method that takes a CallContext. The compiler emits a call to this before a call to a method that takes a CallContext, when it wants the function result as an Object. It pushes the CallContest state so it can uses the vstack for a temporary, After the method, getFromContext extract the method's result from the vstack and restores the state.

writeValue

public void writeValue(Object value)

Write values (of function result) to current consumer.