avoid cfg svg in public macro

turtle-lib/src/export.rs

@@ -1,6 +1,7 @@
 //! Export-Backend-Trait und zentrale Export-Typen
 
 use crate::state::TurtleWorld;
+use crate::TurtlePlan;
 
 #[derive(Debug)]
 pub enum ExportError {
@@ -36,3 +37,50 @@ pub fn parse_svg_export_arg() -> Option<String> {
     }
     None
 }
+
+/// Handle the optional `--export-svg` CLI flag.
+///
+/// The feature gating lives inside `turtle-lib`, so the `turtle_main` macro
+/// no longer needs to reference cfg flags from the consuming crate.
+pub fn handle_svg_export<F>(build_commands: F)
+where
+    F: FnMut(&mut TurtlePlan),
+{
+    // Avoid unused warnings when the feature is disabled
+    let _ = &build_commands;
+
+    if let Some(filename) = parse_svg_export_arg() {
+        #[cfg(feature = "svg")]
+        {
+            let mut build_commands = build_commands;
+            let mut turtle = crate::create_turtle_plan();
+            build_commands(&mut turtle);
+
+            let mut app = crate::TurtleApp::new().with_commands(turtle.build());
+            app.set_all_turtles_speed(crate::AnimationSpeed::Instant(1000));
+
+            while !app.all_animations_complete() {
+                app.update();
+            }
+
+            match app.export_drawing(&filename, crate::export::DrawingFormat::Svg) {
+                Ok(_) => {
+                    println!("SVG exported successfully to: {}", filename);
+                    std::process::exit(0);
+                }
+                Err(e) => {
+                    eprintln!("Error exporting SVG: {:?}", e);
+                    std::process::exit(1);
+                }
+            }
+        }
+
+        #[cfg(not(feature = "svg"))]
+        {
+            let _ = &filename;
+            eprintln!("Error: SVG export feature is not enabled.");
+            eprintln!("Please rebuild with --features svg");
+            std::process::exit(1);
+        }
+    }
+}