<type_designator> "{" [<ivar_inits>] "}"
The type_designator must name a class type (10.4)); this
gives the type of the constructed object. All class constructor
expressions have a (possibly empty) ivar_inits section
surrounded by curly braces. This section consists of two parts:
<ivar_inits> -> <field_inits> ";" <maker_invoc> | <field_inits> | <maker_invoc>
<field_inits> -> <field_init> ["," <field_init>]*
<field_init> -> <idn> ":=" <expr>
<maker_invoc> -> <idn> [<actual_parms>] "(" [<args>] ")"
<actual_parms> -> "[" <type_list> "]"
<type_list> -> <type_designator> ["," <type_designator>]*
The field_inits part initializes the instance variables of
the class; there must be one field_init for each instance
variable. (If the class has no instance variables,
field_inits is not used.) The maker_invoc part is
used to initialize inherited instance variables. This invocation is
present iff the class named by the type_designator has a
superclass (10.5.3); [tex2html_wrap2910] must name a maker (10.5.2)
provided by (10.5.1) the superclass.
The constructor creates a new object of the class type, evaluates the field_init expressions (in an arbitrary order), assigns the results to the associated instance variables of the new object, and calls the superclass maker if the maker_invoc part is present. If all of these steps terminate normally (i.e., they do not raise an exception), the class construction expression terminates normally with the newly-created object as the result.
For example if a class "C" has two instance variables, "x" of type "int" and "y" of type "char", and does not have a superclass, then
n: C := C {x := 3, y := 'A'}
creates a new "C" object with the indicated values in its instance variables
and assigns it to n.