Type members (ref) - vilinski/nemerle GitHub Wiki

The following fields are allowed in class, module and variant body:

type_member =
  field_definition
| property_definition
| event_definition
| method_definition
| type_declaration

Table of Contents Field definition Property definition Event definition Interface member Method definition Operator definition Method header Method parameters Method body

Field definition

field_definition =
Attributes_(ref):attributes Lexical_structure_(ref):IDENTIFIER ':'
Type_expressions_(ref):type [ '=' Expressions_(ref):expr ] ';'

Unless the optional mutable attribute is used, the field can be modified only inside the constructor.

Property definition

property_definition =
attributes IDENTIFIER ':' type '{' property_body '}'

property_body =
  { field_definition } 'get' method_body [ 'set' method_body ]
| { field_definition } 'set' method_body [ 'get' method_body ]

The fields defined in a property are local for it, they cannot be referenced outside the property.

Event definition

event_definition =
attributes 'event' IDENTIFIER : type '{' event_body '}'

event_body =
  'add' Expressions_(ref):block 'remove' block
| 'remove' block 'add' block

Interface member

interface_member =
[ 'new' ] method_header ';'
| [ 'new' ] 'event' IDENTIFIER ':' type ';'
| [ 'new' ] IDENTIFIER ':' type property_body

Keyword new is necessary when the declared method hides the inherited one from another interface.

Method definition

method_definition =
attributes method_header method_body

This is a definition of method within class or module. Program entry point is method static Main.

Operator definition

operator_definition =
attributes method_header method_body

Operator definitions must have the static attribute. The name of method must be simply any valid OPERATOR, which can be then used (as a prefix or unary operator) on expressions of type specified by parameters.

Method header

method_type_parameters =
'[' IDENTIFIER { ',' IDENTIFIER } ']'

The declaration of a polymorphic method needs its type variables listed after the identifier.

method_header =
IDENTIFIER [ method_type_parameters ] '(' method_parameters ')' ':' 
type [ where_constraints ] method_implements
| 'this' [ method_type_parameters ] '(' method_parameters ')'

This is a declaration of method. Unlike in C#, the type is specified after the parameters list.

A special method named this specifies a constructor. This declaration cannot contain the method type and the method has to have type void.

method_implements =
[ 'implements' Expressions_(ref):qualified_identifier 
{ ',' qualified_identifier } ]

Method parameters

method_parameter =
[ 'params' ] Expressions_(ref):identifier_or_dummy [ ':' type ]

A method parameter is a pair consisting of identifier or _ and its type specification. Type declaration can be omitted in local functions definitions.

method_parameters =
[ method_parameter { ',' method_parameter } ]

Method parameters are comma-separated list of parameter specification.

Method body

method_body =
';' | block

Body of a method can be empty, or be a block.