Some ported examples in algebra mode

examples/handle_algebra.py

@@ -0,0 +1,37 @@
+from alg123d import *
+
+segment_count = 6
+
+# Create a path for the sweep along the handle - added to pending_edges
+handle_center_line = Spline(
+    ((-10, 0, 0), (0, 0, 5), (10, 0, 0)),
+    tangents=((0, 0, 1), (0, 0, -1)),
+    tangent_scalars=(1.5, 1.5),
+)
+# Record the center line for display and workplane creation
+handle_path = handle_center_line.edges()[0]
+
+
+# Create the cross sections - added to pending_faces
+
+with LazyAlgCompound() as sections:
+    for i in range(segment_count + 1):
+        plane = Plane(
+            origin=handle_path @ (i / segment_count),
+            z_dir=handle_path % (i / segment_count),
+        )
+        if i % segment_count == 0:
+            section = plane * Circle(1)
+        else:
+            section = plane * Rectangle(1.25, 3)
+            section = fillet(section, section.vertices(), radius=0.2)
+        sections += section
+
+# Create the handle by sweeping along the path
+handle = sweep(sections.faces(), path=handle_path, multisection=True)
+
+if "show_object" in locals():
+    show_object(handle_path.wrapped, name="handle_path")
+    for i, section in enumerate(sections):
+        show_object(section.wrapped, name="section" + str(i))
+    show_object(handle, name="handle", options=dict(alpha=0.6))