forward declaration

examples/issue-01.sx

@@ -0,0 +1,41 @@
+#import "modules/std.sx";
+
+// Forward references: types, struct fields, methods, and free functions
+// can reference types declared later in the file.
+
+// Free function referencing types declared later
+make_frame :: (e: EdgeInsets) -> Frame {
+    Frame.{ x = e.left, y = e.top,
+            w = 100.0 - e.left - e.right,
+            h = 100.0 - e.top - e.bottom };
+}
+
+// Struct with a field whose type is declared later
+Container :: struct {
+    frame: Frame;
+    insets: EdgeInsets;
+}
+
+Frame :: struct {
+    x, y, w, h: f32;
+
+    inset :: (self: Frame, insets: EdgeInsets) -> Frame {
+        Frame.{ x = self.x + insets.left, y = self.y + insets.top,
+                w = self.w - insets.left - insets.right,
+                h = self.h - insets.top - insets.bottom };
+    }
+}
+
+EdgeInsets :: struct {
+    top, left, bottom, right: f32;
+}
+
+main :: () {
+    e := EdgeInsets.{ top = 10.0, left = 10.0, bottom = 10.0, right = 10.0 };
+    f := make_frame(e);
+    r := f.inset(e);
+    c := Container.{ frame = f, insets = e };
+    print("{}", r.x);
+    print(" {}", r.w);
+    print(" {}", c.frame.x);
+}