simkin
Class ExecutableRoot

java.lang.Object
  |
  +--simkin.ExecutableRoot

All Implemented Interfaces:

Executable

Direct Known Subclasses:

Interpreter, TreeNodeObject, XMLElementObject

public class ExecutableRoot

extends java.lang.Object

implements Executable

This class provides an implementation of the Executable interface which can be conveniently extended

The class implements some commonly used methods via the method function:

• the method "trace" which outputs a message to a tracer.
• the method "isObject" which returns true if the argument is an object
• the method "length" which returns the length of a string
• the method "charAt" which returns a character within a string

the method "toString" which coerces the parameter to a string

the method "toInt" which coerces the parameter to an integer

the method "toFloat" which coerces the parameter to a floating point value

the method "toChar" which coerces the parameter to a character

the method "toBool" which coerces the parameter to a boolean

It also implements all the methods of the Executable interface which means that derived classes need only implement the methods they need to override.

The class uses the Interpreter's reflection methods to look for public fields and method names which match those being accessed by the Simkin script.

Constructor Summary

ExecutableRoot()

Method Summary

ExecutableIterator	createIterator() Returns null - by default can't be iterated over
ExecutableIterator	createIterator(java.lang.String qualifier) Returns null - by default can't be iterated over
java.util.Hashtable	getAttributes() This method returns the attributes for this object.
java.util.Hashtable	getInstanceVariables() This method returns the instance variables for this object.
java.lang.String	getSource(java.lang.String location) This method returns the source for a scripted method described by the location.
java.lang.Object	getValue(java.lang.String field_name, java.lang.String attrib, ExecutableContext ctxt) This method calls the Interpreter's reflectiveGetValue method
java.lang.Object	getValueAt(java.lang.Object array_index, java.lang.String attrib, ExecutableContext ctxt) This method does nothing at this level
java.lang.Object	method(java.lang.String method_name, java.lang.Object[] arguments, ExecutableContext ctxt) The following methods are supported directly by this class:
void	setValue(java.lang.String field_name, java.lang.String attrib, java.lang.Object value, ExecutableContext ctxt) This method calls the Interpreter's reflectiveSetValue method
void	setValueAt(java.lang.Object array_index, java.lang.String attrib, java.lang.Object value, ExecutableContext ctxt) This method does nothing at this level

Methods inherited from class java.lang.Object

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

Constructor Detail

ExecutableRoot

public ExecutableRoot()

Method Detail

setValue

public void setValue(java.lang.String field_name,
                     java.lang.String attrib,
                     java.lang.Object value,
                     ExecutableContext ctxt)
              throws java.lang.RuntimeException,
                     FieldNotSupportedException

This method calls the Interpreter's reflectiveSetValue method

Specified by:

setValue in interface Executable

Parameters:

field_name - the name of the field

attrib - the name of the attribute to be set (can be null)

value - the value to be set

ctxt - the context the function is called within

Throws:

java.lang.RuntimeException - - if there was a problem running the script (such as not having permission to access a field)

FieldNotSupportedException - - if the field could not be found

setValueAt

public void setValueAt(java.lang.Object array_index,
                       java.lang.String attrib,
                       java.lang.Object value,
                       ExecutableContext ctxt)
                throws java.lang.RuntimeException

This method does nothing at this level

Specified by:

setValueAt in interface Executable

Parameters:

array_index - an object whose value indicates the index of the item in the collection

attrib - the name of the attribute to be set (can be null)

value - the value to be set

ctxt - the context the function is called within

Throws:

java.lang.RuntimeException - - if there was a problem running the script

getValue

public java.lang.Object getValue(java.lang.String field_name,
                                 java.lang.String attrib,
                                 ExecutableContext ctxt)
                          throws java.lang.RuntimeException,
                                 FieldNotSupportedException

This method calls the Interpreter's reflectiveGetValue method

Specified by:

getValue in interface Executable

Parameters:

field_name - the name of the field

attrib - attribute name (null if no attribute specified)

ctxt - the context the function is called within

Returns:

the value of the field (or null, if the field is not supported)

Throws:

java.lang.RuntimeException - - if there was a problem running the script (such as not having permission to access a field)

FieldNotSupportedException - - if the field could not be found

getValueAt

public java.lang.Object getValueAt(java.lang.Object array_index,
                                   java.lang.String attrib,
                                   ExecutableContext ctxt)
                            throws java.lang.RuntimeException

This method does nothing at this level

Specified by:

getValueAt in interface Executable

Parameters:

array_index - an object whose value indicates the index of the item in the collection

attrib - attribute name (null if no attribute specified)

ctxt - the context the function is called within

Returns:

the value of the object (null if not present)

Throws:

java.lang.RuntimeException - - if there was a problem running the script

method

public java.lang.Object method(java.lang.String method_name,
                               java.lang.Object[] arguments,
                               ExecutableContext ctxt)
                        throws ParseException,
                               java.lang.RuntimeException,
                               MethodNotSupportedException

The following methods are supported directly by this class:

trace(a) - sends a message to the trace output, takes a variable number of arguments

isObject(a) - returns true if a is an object (as opposed to an integer or string)

length(a) - returns the length of a (taken as a string)

charAt(str,index) - returns the character at the given index within the string

If the method is not one of these, the Interpreter's reflectiveMethodCall method is called

Specified by:

method in interface Executable

Parameters:

method_name - the name of the method

arguments - an array of arguments passed to the method

ctxt - the context the function is called within

Returns:

true if the method is found

Throws:

java.lang.RuntimeException - - if there was a problem running the script (such as divide by zero)

ParseException

MethodNotSupportedException

createIterator

public ExecutableIterator createIterator()

Returns null - by default can't be iterated over

Specified by:

createIterator in interface Executable

Returns:

a new iterator object, or null if this object cannot be iterated

createIterator

public ExecutableIterator createIterator(java.lang.String qualifier)

Returns null - by default can't be iterated over

Specified by:

createIterator in interface Executable

Parameters:

qualifier - - a string that can be used to qualify the iteration in any way

Returns:

a new iterator object, or null if this object cannot be iterated

getSource

public java.lang.String getSource(java.lang.String location)

This method returns the source for a scripted method described by the location. At this level it returns a blank string.

Specified by:

getSource in interface Executable

Parameters:

location - the location of the method - in the format passed to the execute functions in the Interpreter

Returns:

the source for the method

getInstanceVariables

public java.util.Hashtable getInstanceVariables()

This method returns the instance variables for this object. At this level it returns null.

Specified by:

getInstanceVariables in interface Executable

Returns:

table a table to filled with references to the instance variables. Each entry in the table maps a name to an object

getAttributes

public java.util.Hashtable getAttributes()

This method returns the attributes for this object. At this level it returns null.

Specified by:

getAttributes in interface Executable

Returns:

table a table filled with the attribute values. Each entry in the table maps an attribute name to a value