sisc.interpreter
Class Interpreter

java.lang.Object
  sisc.util.Util
      sisc.interpreter.Interpreter

All Implemented Interfaces:

Version

public class Interpreter
extends Util

The SISC engine.

Interpreter is the SISC engine. It contains the engine registers, and the main loop responsible for repeatedly executing the nxp register and maintaining the stack. Interpreter also localizes all thread-specific information. Interpreters must only execute in the thread which created them. Furthermore, nested calls from Java into Scheme must be carried out in fresh interpreter instances; thus at any point in time a thread contains a stack of interpreters, the top of which is the interpreter currently in use.

Additionally, it is the interface from Java code for evaluating Scheme code or calling Scheme procedures.

See Also:

Context

Nested Class Summary

static class

Interpreter.ThrowSchemeException

Field Summary

Value	acc
static Compiler	compiler
protected Value[]	dv1
protected Value[]	dv2
protected Value[]	dv3
protected Value[]	dv4
DynamicEnvironment	dynenv
Value[]	env
CallFrame	fk
protected CallFrame	frameFreeList
protected int	frameFreeListSize
protected static int	FRAMEPOOLMAX
Value[][]	IAI
Value[]	lcl
Expression	nxp
ThreadContext	tctx
SymbolicEnvironment	tpl
Value[]	vlr

Fields inherited from class sisc.util.Util

BACKQUOTE, BEGIN, bundles, caseSensitive, EMPTYLIST, EMPTYVEC, EOF, ERRORK, EVAL, EXPSC, EXPTOP, FALSE, FCONT, FIVE, JEXCEPTION, LAMBDA, LOCATION, maxFloatPrecision, MESSAGE, minFloatPrecision, NAME, OTHER, PARENT, permitInterrupts, QUOTE, QUOTESYM, REPORT, SETBANG, SISC, SISC_SPECIFIC, SISCB, SOURCE_COLUMN, SOURCE_FILE, SOURCE_LINE, SYMENV, THIS, TOPLEVEL, TRUE, UNQUOTE, UNQUOTE_SPLICING, VOID, ZV

Fields inherited from interface sisc.util.Version

VERSION

Constructor Summary

Interpreter(ThreadContext tctx, DynamicEnvironment dynenv)

Method Summary

Procedure	captureContinuation()
Procedure	captureEscapingContinuation()
Expression	compile(Value v)
Expression	compile(Value v, SymbolicEnvironment env)
Value[]	createValues(int size)
void	define(Symbol s, Value v, Symbol context) Defines a new binding in a named environment.
void	defineContextEnv(Symbol s, SymbolicEnvironment env)
void	error(Pair error)
Value	eval(Procedure p, Value[] args) Applies the given procedure to the given values
Value	eval(java.lang.String expr) Parses and evaluates s-expression(s)
Value	eval(Value v) Evaluates a Scheme value as code.
Value	eval(Value v, SymbolicEnvironment env) Evaluates a Scheme value as code.
Value	evalInput(java.io.PushbackReader port) Parses and evaluates s-expression(s) from an input port
SymbolicEnvironment	getContextEnv(Symbol s)
AppContext	getCtx()
Symbol	getSymbol(java.lang.String v)
protected void	interpret()
Value	interpret(Expression e)
boolean	loadSourceFiles(java.lang.String[] files) Loads zero or more Scheme source files or compiled libraries.
Expression	lookup(Symbol s, Symbol context) Retrieves the value of a binding in a named environment
SymbolicEnvironment	lookupContextEnv(Symbol s)
StackTracer	makeStackTracer()
void	newVLR(int size)
void	newVLR(Value[] vlr)
void	next(Expression nextExpr)
void	pop(CallFrame c)
void	push(Expression n)
void	pushExpr(Expression e)
void	returnFrame(CallFrame f)
void	returnValues(Value[] v)
void	returnVLR()
void	setFailureContinuation(Expression e)
void	setupTailCall(Expression e, Value vlr0)
void	setupTailCall(Expression e, Value[] newvlr)
void	setVLR(int pos, Value v)
void	trace(Expression e)
void	undefine(Symbol s, Symbol context) Removes a binding in a named environment
Value[]	vlrToArgs() Returns a Value[] prepared as a value rib for a procedure with a fixed argument count.
Value[]	vlrToRestArgs(int fcount) Returns a Value[] prepared as a value rib for a for procedure expecting rest args in the last rib position.

Methods inherited from class sisc.util.Util

annotated, annotatedAppEval, append, argCheck, argsToSymbols, assq, bininport, bininstream, binoutport, binoutstream, box, character, charinport, charinreader, charoutport, charoutwriter, charsetFromString, chr, cont, currentClassLoader, env, error, error, error, error, error, error, error, expr, getDefaultCharacterSet, immutablePair, immutableVector, inport, javaExceptionToString, javaWrap, justify, length, liMessage, liMessage, liMessage, liMessage, liMessage, liMessage, liMessage, list, list, list, list, list, makeURL, mapcar, memq, nlib, num, outport, pair, pairToExpressions, pairToExpVect, pairToValues, proc, read, registerBundle, reverse, reverseInPlace, simpleErrorToString, sourceAnnotations, str, string, sym, symbol, symval, truePair, truth, truth, typeError, typeError, updateName, url, url, url, valArrayToList, valArrayToList, valArrayToVec, vec, warn, warn, warn

Methods inherited from class java.lang.Object

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

Field Detail

compiler

public static Compiler compiler

tctx

public ThreadContext tctx

dynenv

public DynamicEnvironment dynenv

IAI

public Value[][] IAI

acc

public Value acc

nxp

public Expression nxp

vlr

public Value[] vlr

lcl

public Value[] lcl

env

public Value[] env

fk

public CallFrame fk

tpl

public SymbolicEnvironment tpl

FRAMEPOOLMAX

protected static final int FRAMEPOOLMAX

See Also:

Constant Field Values

frameFreeList

protected CallFrame frameFreeList

frameFreeListSize

protected int frameFreeListSize

dv1

protected Value[] dv1

dv2

protected Value[] dv2

dv3

protected Value[] dv3

dv4

protected Value[] dv4

Constructor Detail

Interpreter

public Interpreter(ThreadContext tctx,
                   DynamicEnvironment dynenv)

Method Detail

getCtx

public AppContext getCtx()

getSymbol

public Symbol getSymbol(java.lang.String v)

compile

public Expression compile(Value v)
                   throws ContinuationException

Throws:

ContinuationException

compile

public Expression compile(Value v,
                          SymbolicEnvironment env)
                   throws ContinuationException

Throws:

ContinuationException

interpret

public Value interpret(Expression e)
                throws SchemeException

Throws:

SchemeException

interpret

protected void interpret()
                  throws SchemeException

Throws:

SchemeException

next

public final void next(Expression nextExpr)
                throws ContinuationException

Throws:

ContinuationException

newVLR

public final void newVLR(int size)

newVLR

public final void newVLR(Value[] vlr)

pop

public final void pop(CallFrame c)

makeStackTracer

public final StackTracer makeStackTracer()

setVLR

public final void setVLR(int pos,
                         Value v)

pushExpr

public final void pushExpr(Expression e)

setFailureContinuation

public final void setFailureContinuation(Expression e)

captureContinuation

public final Procedure captureContinuation()

captureEscapingContinuation

public final Procedure captureEscapingContinuation()

trace

public void trace(Expression e)

error

public void error(Pair error)
           throws ContinuationException

Throws:

ContinuationException

evalInput

public Value evalInput(java.io.PushbackReader port)
                throws java.io.IOException,
                       SchemeException

Parses and evaluates s-expression(s) from an input port

Parameters:

port - input port

Returns:

The value of the last evaluated s-expression

Throws:

java.io.IOException - Raised if the port does not contain a parseable s-expression

Interpreter.ThrowSchemeException - Raised if the evaluation of an expression results in an error

SchemeException

eval

public Value eval(java.lang.String expr)
           throws java.io.IOException,
                  SchemeException

Parses and evaluates s-expression(s)

Parameters:

expr - s-expressions(s)

Returns:

The value of the last evaluated s-expression

Throws:

java.io.IOException - Raised if the given string does not contain a parseable s-expression

Interpreter.ThrowSchemeException - Raised if the evaluation of an expression results in an error

SchemeException

eval

public Value eval(Value v)
           throws SchemeException

Evaluates a Scheme value as code. This is equivalent to (eval v) in Scheme.

Parameters:

v - A Scheme Value

Returns:

The resulting value

Throws:

Interpreter.ThrowSchemeException - Raised if the evaluation of the expression results in an error

SchemeException

eval

public Value eval(Value v,
                  SymbolicEnvironment env)
           throws SchemeException

Evaluates a Scheme value as code. This is equivalent to (eval v e) in Scheme.

Parameters:

v - A Scheme Value

env - The environment in which to evaluate the value

Returns:

The resulting value

Throws:

Interpreter.ThrowSchemeException - Raised if the evaluation of the expression results in an error

SchemeException

eval

public Value eval(Procedure p,
                  Value[] args)
           throws SchemeException

Applies the given procedure to the given values

Parameters:

p - A procedure

args - Arguments to call the procedure with

Returns:

The result returned by the procedure

Throws:

Interpreter.ThrowSchemeException - Raised if applying the procedure results in an error

SchemeException

loadSourceFiles

public boolean loadSourceFiles(java.lang.String[] files)

Loads zero or more Scheme source files or compiled libraries.

Parameters:

files - An array of Strings naming files to load.

Returns:

true on success, false if any source file produced an error.

lookupContextEnv

public SymbolicEnvironment lookupContextEnv(Symbol s)

defineContextEnv

public void defineContextEnv(Symbol s,
                             SymbolicEnvironment env)

getContextEnv

public SymbolicEnvironment getContextEnv(Symbol s)

define

public void define(Symbol s,
                   Value v,
                   Symbol context)

Defines a new binding in a named environment.

Parameters:

s - The name of the new binding

v - The value of the new binding

context - The name of the environment in which to create the binding

lookup

public Expression lookup(Symbol s,
                         Symbol context)

Retrieves the value of a binding in a named environment

Parameters:

s - The name of the binding

context - The name of the environment from which the binding will be retrieved

Returns:

A value or expression

undefine

public void undefine(Symbol s,
                     Symbol context)

Removes a binding in a named environment

Parameters:

s - The name of the binding

context - The name of the environment from which the binding will be retrieved

push

public final void push(Expression n)

returnFrame

public final void returnFrame(CallFrame f)

createValues

public final Value[] createValues(int size)

returnVLR

public final void returnVLR()

setupTailCall

public final void setupTailCall(Expression e,
                                Value vlr0)

setupTailCall

public final void setupTailCall(Expression e,
                                Value[] newvlr)

returnValues

public final void returnValues(Value[] v)

vlrToArgs

public Value[] vlrToArgs()

Returns a Value[] prepared as a value rib for a procedure with a fixed argument count. This may or may not clone the VLR depending on whether it is safe to not do so.

vlrToRestArgs

public Value[] vlrToRestArgs(int fcount)

Returns a Value[] prepared as a value rib for a for procedure expecting rest args in the last rib position. This may or may not clone the VLR depending on whether it is safe to not do so.

Parameters:

fcount - The number of arguments to prepare including the rest variable