2.2 KiB
Grammar of the schema language
schema = include* ( namespace_decl | type_decl | enum_decl | root_decl | file_extension_decl | file_identifier_decl | attribute_decl | rpc_decl | object )*
include = include string_constant ;
namespace_decl = namespace ident ( . ident )* ;
attribute_decl = attribute ident | "ident" ;
type_decl = ( table | struct ) ident metadata { field_decl+ }
enum_decl = ( enum ident [ : type ] | union ident ) metadata {
commasep( enumval_decl ) }
root_decl = root_type ident ;
field_decl = ident : type [ = scalar ] metadata ;
rpc_decl = rpc_service ident { rpc_method+ }
rpc_method = ident ( ident ) : ident metadata ;
type = bool | byte | ubyte | short | ushort | int | uint |
float | long | ulong | double |
int8 | uint8 | int16 | uint16 | int32 | uint32| int64 | uint64 |
float32 | float64 |
string | [ type ] | ident
enumval_decl = ident [ = integer_constant ]
metadata = [ ( commasep( ident [ : single_value ] ) ) ]
scalar = integer_constant | float_constant
object = { commasep( ident : value ) }
single_value = scalar | string_constant
value = single_value | object | [ commasep( value ) ]
commasep(x) = [ x ( , x )* ]
file_extension_decl = file_extension string_constant ;
file_identifier_decl = file_identifier string_constant ;
string_constant = \".*?\"
ident = [a-zA-Z_][a-zA-Z0-9_]*
[:digit:] = [0-9]
[:xdigit:] = [0-9a-fA-F]
dec_integer_constant = [-+]?[:digit:]+
hex_integer_constant = [-+]?0[xX][:xdigit:]+
integer_constant = dec_integer_constant | hex_integer_constant
dec_float_constant = [-+]?(([.][:digit:]+)|([:digit:]+[.][:digit:]*)|([:digit:]+))([eE][-+]?[:digit:]+)?
hex_float_constant = [-+]?0[xX](([.][:xdigit:]+)|([:xdigit:]+[.][:xdigit:]*)|([:xdigit:]+))([pP][-+]?[:digit:]+)
special_float_constant = [-+]?(nan|inf|infinity)
float_constant = decimal_float_constant | hexadecimal_float_constant | special_float_constant
boolean_constant = (true|false) | (integer_constant ? true : false)