1Grammar of the schema language    {#flatbuffers_grammar}
2==============================
3
4schema = include*
5         ( namespace\_decl | type\_decl | enum\_decl | root\_decl |
6           file_extension_decl | file_identifier_decl |
7           attribute\_decl | rpc\_decl | object )*
8
9include = `include` string\_constant `;`
10
11namespace\_decl = `namespace` ident ( `.` ident )* `;`
12
13attribute\_decl = `attribute` string\_constant `;`
14
15type\_decl = ( `table` | `struct` ) ident metadata `{` field\_decl+ `}`
16
17enum\_decl = ( `enum` ident [ `:` type ] | `union` ident )  metadata `{`
18commasep( enumval\_decl ) `}`
19
20root\_decl = `root_type` ident `;`
21
22field\_decl = ident `:` type [ `=` scalar ] metadata `;`
23
24rpc\_decl = `rpc_service` ident `{` rpc\_method+ `}`
25
26rpc\_method = ident `(` ident `)` `:` ident metadata `;`
27
28type = `bool` | `byte` | `ubyte` | `short` | `ushort` | `int` | `uint` |
29`float` | `long` | `ulong` | `double` |
30`int8` | `uint8` | `int16` | `uint16` | `int32` | `uint32`| `int64` | `uint64` |
31`float32` | `float64` |
32`string` | `[` type `]` | ident
33
34enumval\_decl = ident [ `=` integer\_constant ]
35
36metadata = [ `(` commasep( ident [ `:` single\_value ] ) `)` ]
37
38scalar = integer\_constant | float\_constant
39
40object = { commasep( ident `:` value ) }
41
42single\_value = scalar | string\_constant
43
44value = single\_value | object | `[` commasep( value ) `]`
45
46commasep(x) = [ x ( `,` x )\* ]
47
48file_extension_decl = `file_extension` string\_constant `;`
49
50file_identifier_decl = `file_identifier` string\_constant `;`
51
52integer\_constant = `-?[0-9]+` | `true` | `false`
53
54float\_constant = `-?[0-9]+.[0-9]+((e|E)(+|-)?[0-9]+)?`
55
56string\_constant = `\".*?\"`
57
58ident = `[a-zA-Z_][a-zA-Z0-9_]*`
59
60