zerodds-idl-python 1.0.0-rc.3

OMG IDL4 → Python code generator for ZeroDDS (@idl_struct + @dataclass mapping per zerodds-py 1.0).
Documentation

zerodds-idl-python

IDL4 → Python codegen for ZeroDDS. Emits @idl_struct(...) + @dataclass classes usable directly with zerodds.IdlTopic(MyClass) — the encoder/decoder comes from the zerodds-py runtime, this codegen only delivers the annotated classes.

Part of the ZeroDDS project. Safety class STANDARD — forbid(unsafe_code), deterministic codegen.

Status RC phase: phase-2 coverage complete — struct (with inheritance), enum, bitmask, bitset, union, typedef, exception, module nesting, primitives, string, sequence. Not supported remain: valuetype, interface, fixed, map, any — these return a clean IdlPythonError::Unsupported.

Quick Start

use zerodds_idl::config::ParserConfig;
use zerodds_idl_python::{PythonGenOptions, generate_python_module};

let ast = zerodds_idl::parse(
    "struct Greeting { long id; string<128> text; };",
    &ParserConfig::default(),
)?;

let py_src =
    generate_python_module(&ast, &PythonGenOptions::default())?;

assert!(py_src.contains("@idl_struct(typename=\"Greeting\")"));
assert!(py_src.contains("@dataclass"));
assert!(py_src.contains("class Greeting:"));
# Ok::<(), Box<dyn std::error::Error>>(())

In the CLI, zerodds-idlc --python -o <dir> <file.idl> handles the codegen. Output lands as <basename>.py and imports the brands from zerodds.idl.

Generated code

Input:

module sensors {
    enum Quality { GOOD, DEGRADED, FAILED };
    struct Reading {
        long sensor_id;
        double value;
        Quality quality;
        sequence<double> history;
    };
};

Output (abbreviated):

# SPDX-License-Identifier: Apache-2.0
# Auto-generated by `zerodds-idl-python`. Do not edit by hand.

from dataclasses import dataclass
from enum import IntEnum
from typing import List
from zerodds.idl import idl_struct, Float64, Int32

class sensors_Quality(IntEnum):
    GOOD = 0
    DEGRADED = 1
    FAILED = 2

@idl_struct(typename="sensors::Reading")
@dataclass
class sensors_Reading:
    sensor_id: Int32
    value: Float64
    quality: sensors_Quality
    history: List[Float64]

Application usage:

from zerodds import DomainParticipant, IdlTopic
from gen.sensors import sensors_Reading, sensors_Quality

p = DomainParticipant(domain_id=0)
topic = IdlTopic(p, sensors_Reading, "sensors")
writer = topic.create_writer()
writer.write(sensors_Reading(
    sensor_id=1,
    value=42.5,
    quality=sensors_Quality.GOOD,
    history=[40.0, 41.2, 42.5],
))

Construct mapping

IDL Python
struct @idl_struct(typename=...) + @dataclass class
struct Foo : Base class Foo(Base): (dataclass inheritance)
enum class X(IntEnum)
bitmask class X(IntFlag) with member = 1 << position
bitset X: TypeAlias = Int64 + class X_Bits: with _SHIFT/_WIDTH/_MASK constants per bitfield
union X = idl_union(typename=..., discriminator=..., cases={...}, default=...)
typedef T name name: TypeAlias = T
exception @idl_struct(typename=...) + @dataclass class X(Exception):
module M { ... } flat class name M_Inner (Python PSM, Annex B)
boolean bool
octet Octet (zerodds.idl brand)
short/long/long long Int16 / Int32 / Int64
unsigned short/unsigned long/unsigned long long UInt16 / UInt32 / UInt64
int8 / uint8 Int8 / UInt8
float / double / long double Float32 / Float64 / LongDouble
char / wchar Char / WChar
string / wstring (bounded or unbounded) String / WString
sequence<T> List[T]
T[N] (array) List[T] (multi-dim nested)
Python reserved word as field name escaped with a _ suffix (class → class_)

Phase 3 (today IdlPythonError::Unsupported)

  • valuetype, interface
  • fixed, map, any
  • union cases with case ENUM_MEMBER: (scoped const expression — follow-up iteration)
  • union cases with binary const expressions (case A | B: etc.)

Spec mapping

Spec document Section
OMG IDL 4.2 (ISO/IEC 19516) §7 — construct mapping
OMG XTypes 1.3 Annex B (Python PSM) class naming convention, discriminator layout
ZeroDDS zerodds-py-1.0 (vendor spec) @idl_struct decorator API, type-brand names

Features

  • default = [] — std-only.

Stability

1.0.0-rc.2. The CLI and library API are stable; emitted code may still change in details before 1.0.0-final (brand imports could be consolidated after a code review).

Tests

cargo test -p zerodds-idl-python

26 smoke tests (phase 1 + phase 2: typedef, exception, bitmask, bitset, union, struct inheritance, module nesting for phase-2 constructs) + 1 doc-test.

See also