.

pipeline/transform/postcode_boundaries/geometry.py

@@ -1,8 +1,8 @@
 """Robust GEOS overlay helpers.
 
 Overlay operations (union, difference, intersection) can raise a
-``GEOSException`` — most often ``TopologyException: side location conflict``,
-``Ring edge missing``, or ``found non-noded intersection`` — on geometries that
+``GEOSException``, most often ``TopologyException: side location conflict``,
+``Ring edge missing``, or ``found non-noded intersection``, on geometries that
 contain near-coincident or near-degenerate edges, or that are individually
 invalid. The robust remedy is a *fixed-precision* overlay: GEOS's OverlayNG
 engine, handed a grid size, nodes every edge onto that grid and finishes where
@@ -14,8 +14,8 @@ learned the hard way from a crash:
 1. **Never precision-reduce with the default mode.** ``set_precision``'s default
    ``valid_output`` (and ``keep_collapsed``) mode runs its *own* noding pass that
    re-raises the very ``side location conflict`` we are trying to escape. We push
-   the grid into the overlay via the ``grid_size`` argument instead — where
-   OverlayNG nodes robustly — and only ever call ``set_precision`` in
+   the grid into the overlay via the ``grid_size`` argument instead (where
+   OverlayNG nodes robustly) and only ever call ``set_precision`` in
    ``pointwise`` mode (pure coordinate rounding, which cannot raise).
 2. **Validate first.** ``make_valid`` repairs the self-intersections (bow-ties,
    pinches) that make GEOS choke, so the overlay starts from an OGC-valid shape.
@@ -40,7 +40,7 @@ from shapely import GEOSException, make_valid, set_precision
 from shapely.geometry import Polygon
 from shapely.ops import unary_union
 
-# 0.1 mm in metres — well below MIN_GEOM_AREA (0.01 m^2) and survey resolution.
+# 0.1 mm in metres: well below MIN_GEOM_AREA (0.01 m^2) and survey resolution.
 _SNAP_GRID = 1e-4
 
 _EMPTY = Polygon()