Target Platform Overview

VSCXML generates state machine code for multiple target platforms. This guide compares the targets and helps you choose the right one for your project.

Table of Contents#

1. Target Comparison
2. Quick Start
3. Architecture
4. Datamodel Support
5. Event Processing
6. Target Guides

Target Comparison#

Feature Matrix#

Quick Start#

Code Generation#

# Java
scxml-gen traffic.scxml -o TrafficLight.java --package com.example

# JavaScript
scxml-gen traffic.scxml -t js -o TrafficLight.js

# C#
scxml-gen traffic.scxml -t csharp -o TrafficLight.cs --namespace Example

# C
scxml-gen traffic.scxml -t c -o traffic_light.c

# Python
scxml-gen traffic.scxml -t python -o TrafficLight.py

# Go
scxml-gen traffic.scxml -t go -o TrafficLight.go

Basic Usage#

Java:

TrafficLight machine = new TrafficLight();
ContinuousStateMachineExecutor executor =
    new ContinuousStateMachineExecutor(machine);
executor.start();
executor.send(EVT_TIMER);
executor.close();

JavaScript:

const machine = new TrafficLight();
machine.start();
machine.send('timer');

C#:

var machine = new TrafficLight();
machine.Start();
machine.Send("timer");

C:

TrafficLight sm;
TrafficLight_init(&sm);
TrafficLight_start(&sm);
TrafficLight_send(&sm, EVT_TIMER, NULL);
TrafficLight_destroy(&sm);

Python:

from traffic_light import TrafficLight

machine = TrafficLight()
machine.start()
machine.send("timer")

Go:

import "./scxmlgen"

machine := NewTrafficLight()
machine.Start()
machine.Send(scxmlgen.NewEvent("timer"))

Architecture#

┌───────────────────────────────────────────────────────────────────────────────────┐
│                               SCXML Source                                          │
│                           (state-machine.scxml)                                     │
└───────────────────────────────────┬───────────────────────────────────────────────┘
                                    │
       ┌────────────┬───────────────┼───────────────┬────────────┬────────────┐
       │            │               │               │            │            │
       ▼            ▼               ▼               ▼            ▼            ▼
  ┌─────────┐  ┌─────────┐    ┌─────────┐    ┌─────────┐  ┌─────────┐  ┌─────────┐
  │ Java    │  │ JS      │    │ C#      │    │ C       │  │ Python  │  │ Go      │
  │Generator│  │Generator│    │Generator│    │Generator│  │Generator│  │Generator│
  └────┬────┘  └────┬────┘    └────┬────┘    └────┬────┘  └────┬────┘  └────┬────┘
       │            │               │               │            │            │
       ▼            ▼               ▼               ▼            ▼            ▼
  ┌─────────┐  ┌─────────┐    ┌─────────┐    ┌─────────┐  ┌─────────┐  ┌─────────┐
  │.java    │  │.js      │    │.cs      │    │.c/.h    │  │.py      │  │.go      │
  │(JVM 11+)│  │(ES6+)   │    │(.NET 6+)│    │(C11)    │  │(3.10+)  │  │(1.21+)  │
  └────┬────┘  └────┬────┘    └────┬────┘    └────┬────┘  └────┬────┘  └────┬────┘
       │            │               │               │            │            │
       ▼            ▼               ▼               ▼            ▼            ▼
  ┌─────────┐  ┌─────────┐    ┌─────────┐    ┌─────────┐  ┌─────────┐  ┌─────────┐
  │scxml-   │  │@scxml-  │    │ScxmlGen.│    │scxml-   │  │scxmlgen │  │scxmlgen │
  │core     │  │gen/     │    │Runtime  │    │runtime  │  │(pip)    │  │(go mod) │
  │runtime  │  │runtime  │    │(NuGet)  │    │(header) │  │         │  │         │
  └─────────┘  └─────────┘    └─────────┘    └─────────┘  └─────────┘  └─────────┘

Generated Code Characteristics#

Datamodel Support#

By Target#

Choosing a Datamodel#

Need scripting?
├── Yes → ecmascript (full W3C compliance)
│         └── Java: Use Rhino or GraalJS
│         └── JS: Uses native JavaScript
│         └── C#: Jint (~2MB)
│         └── C: JerryScript (~200KB)
│         └── Python: dukpy (~2MB)
│         └── Go: Goja (~5MB)
│
└── No → Which target?
         ├── Java → native-java or null
         ├── JavaScript → native-js or null
         ├── C# → native-csharp or null
         ├── C → native-c or null (smallest footprint)
         ├── Python → native-python or null
         └── Go → native-go or null

ECMAScript Engine Comparison#

Event Processing#

Timer Mechanisms#

┌─────────────────────────────────────────────────────────────────────┐
│                   <send event="timeout" delay="3s"/>                 │
└─────────────────────────────────────────────────────────────────────┘
     │              │              │              │              │
     ▼              ▼              ▼              ▼              ▼
┌─────────┐  ┌─────────┐  ┌─────────┐  ┌─────────┐  ┌─────────┐
│  Java   │  │   JS    │  │   C#    │  │    C    │  │ Python  │
├─────────┤  ├─────────┤  ├─────────┤  ├─────────┤  ├─────────┤
│Executor │  │setTimeout│  │Task.    │  │Platform │  │Threading│
│thread   │  │(event   │  │Delay    │  │specific │  │Timer    │
│         │  │loop)    │  │         │  │         │  │         │
└─────────┘  └─────────┘  └─────────┘  └─────────┘  └─────────┘

Event Processing Patterns#

Java - Executor required:

// Background thread handles delayed events
ContinuousStateMachineExecutor executor =
    new ContinuousStateMachineExecutor(machine);
executor.start();
executor.send(EVT_GO);  // Async processing
executor.close();

JavaScript - Native event loop:

// setTimeout handles delayed events automatically
const machine = new TrafficLight();
machine.start();
machine.send('go');  // Processed via event loop

C - Platform-dependent:

// Arduino/bare-metal: Manual tick required
while (running) {
    scxml_executor_tick(sm.executor, elapsed_ms);
    // Process inputs...
}

// Desktop: Timers fire automatically
MyMachine_send(&sm, EVT_GO, NULL);

Target Guides#

Java Target#

Full guide: JAVA.md

Key features:

• Executor patterns (Continuous, RunToCompletion)
• ECMAScript engine switching (Rhino/GraalJS)
• GraalVM native-image support
• Java object binding in scripts

Dependencies:

implementation 'com.scxmlgen:scxml-core:1.0.0'
implementation 'org.mozilla:rhino:1.7.15'

JavaScript Target#

Full guide: JAVASCRIPT.md

Key features:

• ES6+ class generation
• React/Vue/Svelte integration
• Runtime interpreter for dynamic SCXML
• Native setTimeout for delays

Dependencies:

npm install @scxml-gen/runtime  # Optional

C# Target#

Full guide: CSHARP.md

Key features:

• .NET 6+ and .NET Framework 4.7.2+ support
• Jint ECMAScript engine integration
• Unity game engine support
• Full W3C compliance (200/200 tests)

Dependencies:

<PackageReference Include="ScxmlGen.Runtime" Version="1.0.0" />
<PackageReference Include="Jint" Version="3.1.6" />  <!-- For ECMAScript -->

C Target#

Full guide: C.md

Key features:

• Embedded-friendly (Arduino, ESP32, bare-metal)
• Platform-adaptive timer system
• Static memory allocation (MISRA-aware mode)
• JerryScript for ECMAScript

Dependencies:

# None required - copy generated files
# Optional: JerryScript for ECMAScript

Python Target#

Full guide: PYTHON.md

Key features:

• Python 3.10+ with match/case syntax
• dukpy ECMAScript engine integration
• Thread-safe ContinuousExecutor
• Self-contained bundled distribution

Dependencies:

pip install scxmlgen           # Runtime library
pip install dukpy>=0.3.0       # For ECMAScript datamodel

Go Target#

Full guide: GO.md

Key features:

• Go 1.21+ with goroutine-based executor
• Goja ECMAScript engine (pure Go, ES5.1+)
• Thread-safe ContinuousExecutor
• Zero dependencies for null/native-go datamodels

Dependencies:

go get github.com/scxmlgen/scxmlgen           # Runtime library
go get github.com/dop251/goja                 # For ECMAScript datamodel

See Also#

• User Guide - Complete toolchain overview
• Datamodels - Detailed datamodel comparison
• Feature Matrix - SCXML element support
• W3C Compliance - Test results