Print function for debugging

tests/typeset.rs

@@ -70,7 +70,7 @@ fn main() {
     );
     styles.set(TextNode::SIZE, TextSize(Length::pt(10.0).into()));
 
-    // Hook up two more colors and an assert function into the global scope.
+    // Hook up helpers into the global scope.
     let mut std = typst::library::new();
     std.define("conifer", RgbaColor::new(0x9f, 0xEB, 0x52, 0xFF));
     std.define("forest", RgbaColor::new(0x43, 0xA1, 0x27, 0xFF));
@@ -82,6 +82,17 @@ fn main() {
         }
         Ok(Value::None)
     });
+    std.def_fn("print", move |_, args| {
+        print!("> ");
+        for (i, value) in args.all::<Value>()?.into_iter().enumerate() {
+            if i > 0 {
+                print!(", ")
+            }
+            print!("{value:?}");
+        }
+        println!();
+        Ok(Value::None)
+    });
 
     // Create loader and context.
     let loader = FsLoader::new().with_path(FONT_DIR);