sisc.interpreter
Class AppContext

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

All Implemented Interfaces:

Version

public class AppContext
extends Util

The AppContext is the root of all data in an instance of SISC. This encapsulates mainly the procedures and data which are defined in the global environment. It is also the token used by most Java to Scheme operations.

Typically, an AppContext is created using the default constructor, then initialized with a heap using utility methods in REPL.

Field Summary

SymbolicEnvironment	symenv
SymbolicEnvironment	toplevel_env

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

AppContext()
Create a new, AppContext with default values, the recommended constructor for normal usage.

AppContext(java.util.Properties props)
Create a new AppContext, providing a set of properties explicitly.

AppContext(SymbolicEnvironment symenv)
Create a new AppContext, providing a custom global environment.

Method Summary

void	addDefaultHeap() Attempts to find and load the default SISC heap into this AppContext.
boolean	addHeap(SeekableInputStream in) Given a SeekableInputStream which is attached to a SISC heap file, loads the heap into this AppContext and initializes it.
void	defineContextEnv(Symbol s, SymbolicEnvironment env)
static java.net.URL	findHeap(java.net.URL heapLocation) Locate a heap.
Expression	getExpression(Symbol name)
java.lang.String	getProperty(java.lang.String name)
java.lang.String	getProperty(java.lang.String name, java.lang.String def)
void	loadEnv(SeekableDataInputStream i)
LibraryBinding	lookupBinding(Expression e)
SymbolicEnvironment	lookupContextEnv(Symbol s)
static SeekableInputStream	openHeap(java.net.URL u)
Expression	resolveBinding(LibraryBinding lb)
void	saveEnv(java.io.OutputStream o, LibraryBuilder lb)

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

symenv

public SymbolicEnvironment symenv

toplevel_env

public SymbolicEnvironment toplevel_env

Constructor Detail

AppContext

public AppContext()

Create a new, AppContext with default values, the recommended constructor for normal usage.

AppContext

public AppContext(java.util.Properties props)

Create a new AppContext, providing a set of properties explicitly.

Parameters:

props - Properties which govern the underlying Scheme environment.

AppContext

public AppContext(SymbolicEnvironment symenv)

Create a new AppContext, providing a custom global environment.

Parameters:

symenv - the global environment

Method Detail

getExpression

public Expression getExpression(Symbol name)

loadEnv

public void loadEnv(SeekableDataInputStream i)
             throws java.io.IOException,
                    java.lang.ClassNotFoundException

Throws:

java.io.IOException

java.lang.ClassNotFoundException

saveEnv

public void saveEnv(java.io.OutputStream o,
                    LibraryBuilder lb)
             throws java.io.IOException

Throws:

java.io.IOException

lookupContextEnv

public SymbolicEnvironment lookupContextEnv(Symbol s)

defineContextEnv

public void defineContextEnv(Symbol s,
                             SymbolicEnvironment env)

getProperty

public java.lang.String getProperty(java.lang.String name)

getProperty

public java.lang.String getProperty(java.lang.String name,
                                    java.lang.String def)

resolveBinding

public Expression resolveBinding(LibraryBinding lb)
                          throws java.io.IOException

Throws:

java.io.IOException

lookupBinding

public LibraryBinding lookupBinding(Expression e)
                             throws java.io.IOException

Throws:

java.io.IOException

addHeap

public boolean addHeap(SeekableInputStream in)
                throws java.lang.ClassNotFoundException

Given a SeekableInputStream which is attached to a SISC heap file, loads the heap into this AppContext and initializes it. Returns true on success, false otherwise.

Throws:

java.lang.ClassNotFoundException

addDefaultHeap

public void addDefaultHeap()
                    throws java.io.IOException

Attempts to find and load the default SISC heap into this AppContext.

Throws:

java.io.IOException

See Also:

findHeap(URL)

openHeap

public static SeekableInputStream openHeap(java.net.URL u)
                                    throws java.io.IOException

Throws:

java.io.IOException

findHeap

public static java.net.URL findHeap(java.net.URL heapLocation)

Locate a heap. If the heap cannot be located at the supplied location then an attempt is made to find it as a resource "sisc.shp".

Parameters:

heapLocation - The URL for the heap file. When this is null it defaults to the value of the sisc.heap system property and, if that is not present, "sisc.shp"