Zserio Language Quick Reference

Signed Integers and Bitfields

int8
int16
int32
int64
varint16
varint32
varint64
varint
int:n
int<expr>

Unsigned Integers and Bitfields

uint8
uint16
uint32
uint64
varuint16
varuint32
varuint64
varuint
varsize
bit:n
bit<expr>

Floating Points

float16
float32
float64

Booleans

bool

Strings

string

External Types

extern

Bytes Types

bytes

Constants

const bit:1 FALSE = 0;

Enumerations

enum bit:3 Color
{
    NONE = 000b,
    RED = 1,
    BLUE,
    BLACK = 111b
};

Bitmasks

bitmask bit:3 Permission
{
    READ,
    WRITE,
    EXECUTE
};

Structures

struct MyStructure
{
    bit:4 a;
    uint8 b;
    bit:4 c;
};

Unions

union SimpleUnion
{
    bit:4   fieldBit4;
    uint8   fieldUInt8;
    uint16  fieldUInt16;
};

Choices

choice VarCoordXY(uint8 width) on width
{
    case 8:  CoordXY8 coord8;
    case 16: CoordXY16 coord16;
    case 24: CoordXY24 coord24;
    case 32: CoordXY32 coord32;
};

Extended Members

struct TopLevelBlob
{
    uint32 data[];                    // last field in version 1
    extend ExtendedData extendedData; // added in version 2
    extend bool additionalFlag;       // added in version 3
};

Constraints

struct GraphicControlExtension
{
    uint8 byteCount : byteCount == 4;
    uint8 terminator : terminator == 0;
};

Optional Members

struct ItemCount
{
    uint8 count8;
    uint16 count16 if count8 == 0xFF;
};

struct Container
{
    int16           item1;
    optional int32  item2;
};

Functions

struct ItemCount
{
    uint8   count8;
    uint16  count16 if count8 == 0xFF;

    function uint16 getValue()
    {
        return (count8 == 0xFF) ? count16 : count8;
    }
};

Arrays

struct ClassicArrayExample
{
    uint8   header[256];
    int16   numItems;
    Element list[numItems];
};

struct AutoArrayExample
{
    Element list[];

    function uint32 getNumItems()
    {
        return lengthof(list);
    }
}

Alignments

struct AlignmentExample
{
    bit:11 a;

align(32):
    uint32 b;
};

Offsets

struct Tile
{
    TileHeader  header;
    uint32      stringOffset;
    uint16      numFeatures;

stringOffset:
    StringTable stringTable;
};

Indexed Offsets

struct IndexedInt32Array
{
    uint32  offsets[10];
    bit:1   spacer;
offsets[@index]:
    int32   data[10];
};

Parameterized Types

struct Header
{
    uint32 version;
    uint16 numItems;
};

struct Message
{
    Header  header;
    Item(h) items[header.numItems];
};

struct Item(Header header)
{
    uint16  p;
    uint32  q if header.version >= 10;
};

Subtypes

subtype uint16 BlockIndex;

struct Block
{
    BlockIndex  index;
    BlockData   data;
};

Templates

struct Field<T>
{
    T value;
};

instantiate Field<uint32> Field32;

struct Compound<T>
{
    T value;
};

struct StructTemplatedTemplateArgument
{
    Field<Compound<uint32>> compoundField;
};

---

Service Types

struct Request
{
    int16 value;
};

struct Response
{
    uint32 value;
};

service Users
{
    Response powerOfTwo(Request);
};

Pubsub Types

struct MessageType
{
    string text;
};

pubsub PublishSubscribe
{
    topic("topic/definition") MessageType message;
};

---

SQLite extension

SQLite Table

sql_table GeoMap
{
    int32   tileId sql "PRIMARY KEY";
    Tile    tile;
};

sql_table Pages using fts5
{
    string  title;
    string  body;
};

SQLite Database

sql_database TheWorld
{
    GeoMap europe;
    GeoMap america;
    GeoMap africa;
    GeoMap asia;
    GeoMap australia;
};