postfix expression

In general, the term postfix expression is used to describe a unary operator that immediately follows an expression. Ecstasy has six operators that it combines into the PostfixExpression construct:

a()
a[]
a.
a?
a++
a--

The form a. is further sub-divided into four expressions; here is the expanded list of forms:

Op	Expression	Description
a()	InvocationExpression	invoke method or function
a[]	ArrayAccessExpression	access or update array element
a.name	NameExpression	identity or member specifier
a.is	TypeCheckExpression	type test
a.as	TypeCheckExpression	type assertion
a.new	NewExpression	virtual child creation
a?	NotNullExpression	arc if value is null
a++	SequentialExpression	post-increment
a--	SequentialExpression	post-decrement

    PostfixExpression:
        PrimaryExpression
        PostfixExpression ( Argumentsopt )
        PostfixExpression ArrayIndexes
        PostfixExpression .is ( TypeExpression )
        PostfixExpression .as ( TypeExpression )
        PostfixExpression .new TypeExpression ( Argumentsopt )
        PostfixExpression . &opt Name TypeParameterTypeListopt
        PostfixExpression NoWhitespace ?
        PostfixExpression ++
        PostfixExpression --

    TypeParameterTypeList:
        < TypeExpressionList >

    TypeExpressionList:
        TypeExpressionListElement
        TypeExpressionList , TypeExpressionListElement
    
    TypeExpressionListElement:
        TypeParameterTypeList
        TypeExpression

From InvocationExpression:

    Arguments:
        Argument
        Arguments , Argument

    Argument:
        NamedArgumentopt ArgumentExpression

    ArgumentExpression:
        _
        < TypeExpression > _
        Expression

    NamedArgument:
        Name =

From ArrayAccessExpression:

    ArrayIndexes:
        [ ExpressionList ]
        
    ExpressionList:
        Expression
        ExpressionList , Expression