No Documentation Specified


ArrayNo Documentation Specified
Attribute An attribute is a structural feature of a class. It defines the name and type of a slot of the instances of the class. When the class is instantiated, a new object is created and a slot is added for each attribute defined and inherited by the class. Each slot is initialised to contain the default value for the type of the corresponding attribute. Constructor: Attribute(name,type) The name is a string and the type is a classifier.
BasicArrayNo Documentation Specified
BehaviouralFeature A behavioural feature is a typed element that can be invoked. Typically a behavioural feature is an operation.
Bind A binding is a named value. Constructor: Bind(name,value) Constructs a binding, the name is a string and the value is any element.
BufferNo Documentation Specified
Class A class is a classifier with structural features (i.e. attributes). Instances of classes are always objects with slots for the attributes of the class. A class is instantiated using the 'new/0' and 'new/1' operations (inherited from Classifier). The former takes no initialization arguments whereas the latter takes a sequence of initialization arguments. The preferred way of instantiating a class is by applying it as an operator to the initialization arguments, as in C() or C(1,2,3). This instantiates the class and calls 'init/1' on the resulting instance. Typically classes will redefine 'init/1' to initialize new instances on a class-by-class basis. Typically you will create a class using the @Class ... en-d notation.
Classifier A classifier is a name space for operations and constraints. A classifier is generalizable and has parents from which it inherits operations and constraints. A classifier can be instantiated via 'new/0' and 'new/1'. In both cases the default behaviour is to return a default value as an instance. If the classifier is a datatype then the basic value for the datatype is returned otherwise 'null' is returned as the default value. A classifier can also be applied to arguments (0 or more) in order to instantiate it. Typically you will not create a Classifier directly, but create a class or an instance of a sub-class of Class.
CodeBox A CodeBox contains compiled code that can be executed on the XMF VM.
Collection The root class for all collection types.
CompiledOperation CompiledOperation is the type of all XMF compiled operations. A compiled operation can be invoked using 'invoke/2' or by applying it to its arguments. A compiled operation consists of machine code instructions. A compiled operation may be associated with its source code to aid debugging.
Constraint A constraint is a named boolean expression owned by a classifier. Constraints are defined by classifiers to be performed with respect to their instances and as such any occurrences of 'self' in a constraint will refer to the instance that is being checked.
ConstraintReport A constraint report is produced by sen-ding a classify message to an element or a check constraints message to a classifier. A report is a tree structured element describing the constraints that were performed and their outcomes. Note that internal nodes of the tree may have dummy constraint reports used as containers of sub-constraint reports. Such dummies have a null constraint and an empty reason, but the satisfied boolean is the conjunction of the sub-reports.
Constructor A constructor contains a code body that is invoked on instantiation of a classifier.
Contained A contained element has an owner. The owner is set when the contained element is added to a container. Removing an owned element from a container and adding it to another container will change the value of 'owner' in the contained element.
Container A container has a slot 'contents' that is a table. The table maintains the contained elements indexed by keys. By default the leys for the elements in the table are the elements themselves, but sub-classes of container will modify this feature accordingly. Container provides operations for accessing and managing its contents.
Daemon Daemons monitor the state of objects and perform actions when the object changes state. Daemon technology is the key to implementing a variety of modular reusable tool architectures such as the observer pattern. XMF-Mosaic uses daemons extensively to synchronize data across multiple tools. User defined tools can use daemons to make tools reactive and to ensure data is always consistent.
DataType DataType is a sub-class of Classifier that designates the non-object classifiers that are basic to the XMF system. An instance of DataType is a classifier for values (the instances of the data type). For example Boolean is an instance of DataType - it classifies the values 'true' and 'false'. For example Integer is an instance of DataType - it classifies the values 1, 2, etc.
Doc A class used to represent documentation.
DocumentedElement A documented element has an attribute doc:Doc, which is used to store documentation relating to the element. Any class that can be documented should specialize this class.
Element Element is the root class of the XMF type hierarchy. It has no super-classes. Everything is an instance of Element. Operations defined on Element are available to every data value in XMF. Use this as a type when you want to use heterogeneous values (for example as the type of an attribute). An element always has a classifier which is the value of the 'of/0' message. An element can always be sent messages using 'sen-d/2' where the first argument is the name of the message and the second argument is a sequence of message arguments.
Enum The enumerated data type. Create an instance of this class to create a new named enumeration type. The names passed to the constructor are the names of the unique elements of the enumeration. On creation, the names are mapped to instances of the new enumeration type and can be referenced via their name using getElement (or ::).
EnumChoiceNo Documentation Specified
Exception An exception is raised when something goes wrong. An exception contains a message that reports what went wrong. An exception also contains a sequence of stack frames that defines the history of computation at the point the exception was raised. An exception may optionally contain information about where in the source file the error occurred. This is encoded as the lineCount.
ForeignObjectNo Documentation Specified
ForeignOperation Provides an interface to operations written in external programming languages, such as Java.
ForwardRefNo Documentation Specified
IndexedContainer An indexed container is a class that manages a hashtable associating keys with values. The Container::add/1 operation is implemented by IndexedContainer to add the argument as both an index and a value. The class IndexedContainer provides a 2-place operation for 'add' that allows the index to be different from the value. Note that 'remove/1' expects to be supplied with the index.
InitialisedAttributeNo Documentation Specified
InterpretedOperation An interpreted operation is created when we evaluate an operation definition.
MachineExceptionNo Documentation Specified
NameSpace A name space is a container of named elements. A name space defines two operations 'getElement/1' and 'hasElement/1' that are used to get an element by name and check for an element by name. Typically a name space will contain different categories of elements in which case the name space will place the contained elements in its contents table and in a type specific collection. For example, a class is a container for operations, attributes and constraints. Each of these elements are placed in the contents table for the class and in a slot containing a collection with the names 'operations', 'attributes'; and 'constraints' respectively. The special syntax '::' is used to invoke the 'getElement/1' operation on a name space.
NamedElement A named element is an owned element with a name. The name may be a string or a symbol. typically we use symbols where the lookup of the name needs to be efficient.
Object Object is the super-class of all classes with structural features in XMF. Object provides access to slots via the 'get/1' and 'set/2' operations. Object is the default super-class for a class definition - if you do not specify a super-class then Object is assumed.
OpTypeNo Documentation Specified
Operation Operation is the abstract super-class of all operations in XMF. An operation can be compiled or interpreted. All operations have parameters, a return type and a body. The body must be performable. An operation is invoked using 'invoke/2' where the first argument is the value of 'self' in the operation body and the second argument is a sequence of parameter values.
OrderedContainer A container that wraps a collection of ordered elements.
Package XMF supports name spaces that contain collections of named elements. The XCore class Package is used to structure collections of class and sub-package definitions. XMF-Mosaic is structured as a tree of packages containing definitions of all aspects of the system (including XCore). The root name space is called Root; all XMF classes can be referenced via Root. Unlike UML and MOF, XCore packages are subclasses of Class. They can therefore be instantiated and can have operations, attributes and constraints.
Parameter A parameter is a typed element that occurs in operations.
Performable A performable element can be executed on the XMF VM. It must provide a collection of operations that support its evaluation or its translation into VM machine instructions. In particular it must support 'compile/4', 'FV/0', 'maxLocals/0' and 'eval/3'. Performable is the root class for all extensions to executable XMF. For example OCL is a sub-class of Performable. If you inte-nd to define your own languages in XMF then they should exte-nd Performable.
Resource A resource records where the resource originated via a resource name. For example a definition is a resource that records the file where it was loaded from.
Seq Seq is a sub-class of DataType. All sequence data types are an instance of Seq. Seq defines an attribute 'elementType' that is used to record the type of the elements in a sequence data type.
Set Set is a sub-class of DataType. All set data types are an instance of Set. Set defines an attribute 'elementType' that is used to record the type of the elements in a set data type.
SnapshotNo Documentation Specified
StructuralFeature This is an abstract class that is the super-class of all classes that describe structural features. For example Attribute is a sub-class of StructuralFeature. Other types of structural feature are possible by managing the internal structure of objects via a MOP.
Table A table associates keys with values. Any element can be used as a key. A table has an initial size and can support any number of values. Use 'hasKey/1' to determine whether a table contains a key. Use 'get/1' to access a table via a key and 'put/2' to update a table given a key and a value. Use 'keys/0' to access the set of keys for a table.
Thread A thread is a unit of concurrent execution. When a thread is created, it continues processing on the XVM until either it performs a read operation that blocks on input or when it explicitly calls yield. All XOCL values implement the yield operation. In both cases the thread is said to yield control. When a thread yields control, the XOS schedules another thread that is waiting. The scheduling algorithm aims to ensure that all waiting threads get scheduled providing that they yield.
TypedElement A typed element is a named element with an associated type. The type is a classifier. This is an abstract class and is used (for example) to define Attribute.
UnorderedContainer A container that wraps a collection of unordered elements.
Vector A vector is a fixed length array of elements. They are created using the constructor Vector(). Vectors provide very efficient insert ('put/2') and lookup operations ('ref/1').

Boolean The data type for boolean values. A boolean value is either true or false. The default value is false.
Collection(Element)No Documentation Specified
Float The data type for real values. The default value is 0.0
Integer The data type for integer values The default value is 0.
Null Null is the data type for the special value 'null'. The special value 'null' is an instance of all classifiers. It is the default value for all instances of Class.
NumberNo Documentation Specified
Seq(Element) An instance of Seq where the element type is Element. This is the super-type of all sequence data types.
Set(Element) An instance of Set where the element type is Element. This is the super-type of all set data types
String The data type for strings. The default value is the empty string.
Symbol Symbol is a sub-class of String. Whereas there may be two different strings with the same sequence of characters, there can only be one symbol with the same sequence of characters. This is useful when using names as the basis for lookup (in tables). For example XMF ensures that classes, packages, operations, slots are named using symbols so that the lookup of these features by name is as efficient as possible. If strings were used the lookup would necessarily involve a character by character comparison. Using symbols the lookup can use the symbols identity as the comparison operator. You can reference a symbol by constructing an instance: Symbol(name).

noDoc()No Documentation Specified