Version 8 (modified by Chuck, 9 years ago)


Class Definitions

Classes are declared using the class keyword followed by the classname.
The class may have any of the usual access modifiers.
The Superclass inheritance and Interface conformance are indicated with the inherits and implements keywords.

Class Grammar

class <ClassName>  
    [is <AccessModifiers>]
    [has <Attributes>]
    [where <GenericParam> must be <GenericConstraints>]
    [inherits <BaseClassName> ]
    [implements <InterfaceName> [, <InterfaceName>]...]



Interfaces are declared in much the same way except the keyword is interface and method and property bodies are not defined.
Interface hierarchies (SuperInterfaces) can also be specified using inherits

Interface Grammar

interface <InterfaceName>  
    [is <AccessModifiers>]
    [has <Attributes>]
    [where <GenericParam> must be <GenericConstraints>]
    [inherits <BaseInterfaceName> [, <BaseInterfaceName>]... ]


Instance and Class Variables

Instance and Class variables are declared within the class using keyword var.

Instance and Class variable definition Grammar

    var <variableName> [as <Type>]  [is <AccessModifiers>]

    var <variableName> [as <Type>] = <initialValue>
        [is <AccessModifiers>]
        [has <Attributes>]


    var x as String
    var _y as int
    var _ya as int = 47
    var z as int is private
    var t as int = 99
        is protected, shared
        Temporary backup value

All Class and Instance variable names must start with a lowerCase Letter

If the name is prefixed with an _ its accessType defaults to protected and it is directly accessable from within the class method code.

Without that prefix on the name the variables accessType is public, virtual (by default) and it must be accessed from within method code by prefixing the name with either this. or just . .

In either case the default accessModifier? setting can be adjusted with an accessModifier clause.

Class (or static) variables are specified with the access Modifier shared as in is shared e.g.

    var _x = 100
    def tryx( opnd as int) as int
        return _x + opnd

    var y is protected  # default public
    def tryy( opnd as int) as int
        return .y + opnd

    var statX as int = 45
        is shared
    def x 
        print .statX


Define a property for the class

Properties Grammar

get <propName> [ as {<Type>, var}] [is <accessModifier>]
set <propName> [ as {<Type>, var}   [is <accessModifier>]

pro <propName> [ as {<Type>, var}] [is <accessModifier>]

pro <propName> [is <accessModifier>]

        return <value>
        [...] # assign or otherwise do something with implicit arg "value" (passed in) to something 


Methods are defined using the keyword def.

If not specified the returnType is void ( i.e nothing returned) and the access modifiers are public, virtual

Like variables if the name is prefixed with an _ its access modifier defaults to protected and it is directly accessable from within the class method code.

Without that prefix on the name the methods the accessType is public, virtual and it must be accessed from within method code by prefixing the name with either this. or just . .

Method Grammar

    def <methodName> [as <returnType>]  [is <AccessModifiers>]
        [has <Attributes>]
    def <methodName>(<paramList>) [as <returnType>]  [is <AccessModifiers>]
        [has <Attributes>]

The initializer or constructor method of a class is a special method called init which is implicitly called when a class instance is constructed. Its responsible for setting the contents of a class instance to an initial state. It doesnt return any value and is not inherited (i.e baseclass initialization must be done with an explicit call to a baseclass constructor).

If an init method is not specified the compiler runtime generates a noArg constructor that does nothing.

Constructor chaining can be done to another constructor in the same class (usually with a different number or Type of args) or to a Superclass constructor (using base.init) - this call must be the first executable line in the init method.

Method Parameter List

A parameter list is a comma separated list of name (and optionally type and parameter description modifier) specifications

<paramName> [as [<paramDesc>] <Type>]  [, ...]

<paramDesc> is optional and may be vari and/or a parameter direction indicator out or inout ( default if unspecified is in)

vari indicates the parameter name is a placeholder for a variable length arglist. Within the method this may be unpacked/accessed as a list.

in (implicit) Args are only passed into the method. Any changes made to the argument inside the method are not visible outside the method (pass-by-value)

out the arg is returned from the method

inout argument is both passed into the method and (any possibly changed) value is also returned from the method (pass-by-reference)

If <Type> is unspecified it is treated as dynamic?


    def meth( a, b is String, c is out String)
        c = b + "_meth"

    def sum(a as vari int) as int
        sum = 0
        for i in a
            sum += i
        return sum

meth takes 3 args , the first and second are inward only and are dynamic and a string respectively, the third is only returned from the method as a string sum takes a variable number of integer args


+++TBD+++ Generics

++accessing baseclass methods


interface Audible
    def makesNoise as String

interface Mateable
    pro mateName as String

interface Breedable
    inherits Mateable 

    pro childName as String

# class declaration - note indentation
class Bovidae
    def diet as String
        return 'Herbivorous Cud Chewing'
    def numHooves as int
        return 4

class Sheep 
    is public, nonvirtual    # public is default anyway
    inherits Bovidae        # Superclass
    implements Audible, Breedable
    var _lifeSpan as int = 8
         is shared               # years average
    # or var lifeSpan as int private shared

    var _age as int =1
    var liveWeight as int is private
    var _isAlive as bool
	#_lifespan = 8  
    def init
        _age = 1
        .liveWeight = 2
        _isAlive = true

    def makesNoise as String
        return 'Baaaaa'

    pro mateName as String
            return 'Ram'
    pro childName as String
            return 'lamb'

    def age(byNYears as int)
        _age += byNYears
        if _age > _lifeSpan
            _isAlive = false

    def gainWgt(wgt as int)
        .liveWeight += wgt

    def toString as String is new
        return 'Sheep:age=[_age], weight=[.liveWeight], living=[_isAlive]'
    def main is shared
	s = Sheep()
	print 's=[s]'