Lexical Notes (ONC+ Developer's Guide)

ONC+ Developer's Guide

Lexical Notes

Comments begin with /* and end with */.
White space serves to separate items and is otherwise ignored.
An identifier is a letter followed by an optional sequence of letters, digits, or underbars (_). The case of identifiers is not ignored.

A constant is a sequence of one or more decimal digits, optionally preceded by a minus-sign (-).

Example C-1 XDR Specification

Syntax Information
declaration:
	type-specifier identifier
	| type-specifier identifier "[" value "]"
	| type-specifier identifier "<" [ value ] ">"
	| "opaque" identifier "[" value "]"
	| "opaque" identifier "<" [ value ] ">"
	| "string" identifier "<" [ value ] ">"
	| type-specifier "*" identifier
	| "void"

value:
	constant
	| identifier

type-specifier:
	 [ "unsigned" ] "int"
	| [ "unsigned" ] "hyper"
	| "float"
	| "double"
	| "quadruple"
	| "bool"
	| enum-type-spec
	| struct-type-spec
	| union-type-spec
	| identifier

enum-type-spec:
	"enum" enum-body

enum-body:
	"{"
	( identifier "=" value )
	( "," identifier "=" value )*
	"}"

struct-type-spec:
	"struct" struct-body

struct-body:
	"{"
	( declaration ";" )
	( declaration ";" )*
	"}"

 union-type-spec:
	"union" union-body

union-body:
	"switch" "(" declaration ")" "{"
	( "case" value ":" declaration ";" )
	( "case" value ":" declaration ";" )*
	[ "default" ":" declaration ";" ]
	"}"

constant-def:
	"const" identifier "=" constant ";"

type-def:
	"typedef" declaration ";"
	| "enum" identifier enum-body ";"
	| "struct" identifier struct-body ";"
	| "union" identifier union-body ";"

definition:
	type-def
	| constant-def

specification:
	definition *