Module codegen 

Code generation for production builds

This module generates static Rust code from Dampen UI definitions. The generated code has zero runtime overhead compared to hand-written Iced code.

Overview

Code generation is used in production mode to eliminate runtime parsing:

1. Parse .dampen files at build time
2. Generate Rust code with generate_application()
3. Include generated code via include!(concat!(env!("OUT_DIR"), "/ui_generated.rs"))

Example

// At build time:
let doc = parse(ui_xml)?;
let output = generate_application(&doc, "Model", "Message", &handlers)?;
fs::write("ui_generated.rs", output.code)?;

// At runtime:
include!("ui_generated.rs");
// No XML parsing, no runtime overhead!

Generated Code Structure

The generated code includes:

• Message enum from handler signatures
• impl Application for Model with view() and update() methods
• Inlined widget tree with evaluated bindings

Modules

application

Application trait generation

bindings

Binding expression inlining for code generation

config

Configuration for code generation behavior

handlers

Handler dispatch code generation

inventory

Handler inventory extraction for build scripts

status_mapping

Status mapping code generation for widget state styling

subscription

Subscription code generation for production builds

theme

Theme code generation for production builds

update

Update function generation

view

View function generation

Structs

CodegenOutput

Result of code generation

GeneratedApplication

Output structure from code generation

GeneratedCode

Container for generated Rust code with metadata

HandlerInfo

Metadata structure emitted by #[ui_handler] macro for build-time registration

Enums

CodegenError

Errors that can occur during code generation

HandlerSignatureType

Handler signature classification for code generation

Functions

constant_folding

Basic constant folding optimizations for generated code

generate_application

Generate complete application code from a Dampen document

generate_application_with_theme_and_subscriptions

Generate complete application code with theme and subscription support

validate_handlers

Validate that all handlers referenced in the document exist