magmalake avro

avro · API

avro.value

Value — a dynamically typed Avro datum.

Like Schema, a Value is an arena of nodes plus a root index, but the arena sits behind an ArcPointer so navigating (v.field("x").at(0)) is a refcount bump rather than a deep copy. Building a value copies its children into a fresh arena; reading one never copies.

Structs

ValueNode

struct ValueNode

Implements Copyable, Movable

Fields
kind: Int
b: Bool
i: Int64: Int / long payload, and the enum symbol or union branch index.
d: Float64: Float / double payload.
data: List[UInt8]: Bytes / fixed payload.
s: String: String payload, and the enum symbol name.
keys: List[String]: Record field names or map keys, in order.
kids: List[Int]

of

def of(kind: Int) -> Self

Value

struct Value

One Avro datum. Cheap to copy: the node arena is shared.

Implements Copyable, Equatable, Movable, Sized, Writable

Fields
arena: ArcPointer[List[ValueNode]]
idx: Int

__init__

def __init__(out self, var arena: ArcPointer[List[ValueNode]], idx: Int)
def __init__(out self)

__eq__

def __eq__(self, other: Self) -> Bool

__ne__

def __ne__(self, other: Self) -> Bool

null

def null() -> Self

boolean

def boolean(v: Bool) -> Self

int

def int(v: Int64) -> Self

long

def long(v: Int64) -> Self

float

def float(v: Float32) -> Self

double

def double(v: Float64) -> Self

bytes

def bytes(v: Span[UInt8]) -> Self

fixed

def fixed(v: Span[UInt8]) -> Self

string

def string(v: StringSpan) -> Self

enum

def enum(index: Int, symbol: StringSpan) -> Self

array

def array(items: List[Self]) -> Self

map

def map(var keys: List[String], values: List[Self]) -> Self

record

def record(var names: List[String], values: List[Self]) -> Self

union

def union(index: Int, branch: Self) -> Self

kind

def kind(self) -> Int

type_name

def type_name(self) -> String

is_null

def is_null(self) -> Bool

as_bool

def as_bool(self) -> Bool

as_long

def as_long(self) -> Int64

as_int

def as_int(self) -> Int32

as_double

def as_double(self) -> Float64

as_float

def as_float(self) -> Float32

as_string

def as_string(self) -> String

as_bytes

def as_bytes(self) -> List[UInt8]

enum_index

def enum_index(self) -> Int

symbol

def symbol(self) -> String

union_index

def union_index(self) -> Int

unwrap

def unwrap(self) -> Self

The branch value of a union; self for anything else.

__len__

def __len__(self) -> Int

at

def at(self, k: Int) -> Self

Child k — an array element, map value or record field value.

key

def key(self, k: Int) -> String

Name of child k — a record field name or a map key.

index_of

def index_of(self, name: StringSpan) -> Int

Position of a record field or map key, or -1 when absent.

has

def has(self, name: StringSpan) -> Bool

field

def field(self, name: StringSpan) -> Self

A record field (or map entry) by name, unwrapping unions.

field_raw

def field_raw(self, name: StringSpan) -> Self

A record field by name, keeping any union wrapper.

to_json

def to_json(self) -> String

A JSON rendering used by the tests and the fastavro cross-check.

Unions collapse to their branch value and bytes/fixed render as "0x…" hex, so the output lines up with a Python dict dumped the same way.

write_to

def write_to(self, mut writer: T)

RecordBuilder

struct RecordBuilder

Accumulate named fields, then build() a record Value.

var b = RecordBuilder()
b.add("id", Value.long(7))
b.add("name", Value.string("row"))
var v = b^.build()

Implements Copyable, Defaultable, Movable

Fields
names: List[String]
values: List[Value]

__init__

def __init__(out self)

add

def add(mut self, name: StringSpan, value: Value)

build

def build(deinit self) -> Value

ArrayBuilder

struct ArrayBuilder

Accumulate elements, then build() an array Value.

Implements Copyable, Defaultable, Movable

Fields
values: List[Value]

__init__

def __init__(out self)

add

def add(mut self, value: Value)

build

def build(deinit self) -> Value

MapBuilder

struct MapBuilder

Accumulate key/value pairs, then build() a map Value.

Implements Copyable, Defaultable, Movable

Fields
keys: List[String]
values: List[Value]

__init__

def __init__(out self)

add

def add(mut self, key: StringSpan, value: Value)

build

def build(deinit self) -> Value