Preprocess arguments to fix leading minus issue.

`argparse` treats argument of `--coordinates` and `--boundary-box` as
other option if it starts with `-`.  The new solution is to preprocess
arguments adding leading space to the argument value.

map_machine/element/element.py

@@ -9,7 +9,7 @@ from map_machine.osm.osm_reader import Tags, OSMNode
 
 def draw_node(tags: Tags, path: Path):
     """Draw separate node."""
-    grid: Grid = Grid(show_credit=False, margin=3.5)
+    grid: Grid = Grid(show_credit=False, margin=7.5)
     grid.add_node(tags, 0, 0)
     grid.draw(path)
 

map_machine/ui/cli.py

@@ -31,21 +31,20 @@ COMMANDS: list[str] = [
     "taginfo",
 ]
 
-BOUNDARY_BOX_WARNING: str = (
-    "if the first value is negative, use the `=` sign or enclose the value "
-    "with quotes and prefix a space before `-`, e.g. "
-    "`-b=-84.752,39.504,-84.749,39.508` or `-b "
-    '" -84.752,39.504,-84.749,39.508"`'
-)
-COORDINATES_WARNING: str = (
-    "if the first value is negative, use the `=` sign or enclose the value "
-    "with quotes and prefix a space before `-`, e.g. `-c=-84.752,39.504` or "
-    '`-c " -84.752,39.504"`'
-)
-
 
 def parse_arguments(args: list[str]) -> argparse.Namespace:
     """Parse Map Machine command-line arguments."""
+
+    # Preparse arguments adding space before coordinates and boundary box if the
+    # first value is negative.  In that case `argparse` interprets in as an
+    # option name.
+    for argument in "-c", "--coordinates", "-b", "--boundary-box":
+        if argument in args:
+            index: int = args.index(argument) + 1
+            if args[index].startswith("-"):
+                args[index] = " " + args[index]
+            break
+
     parser: argparse.ArgumentParser = argparse.ArgumentParser(
         description="Map Machine. OpenStreetMap renderer with custom icon set"
     )
@@ -217,8 +216,7 @@ def add_tile_arguments(parser: argparse.ArgumentParser) -> None:
         "-c",
         "--coordinates",
         metavar="<latitude>,<longitude>",
-        help="coordinates of any location inside the tile; "
-        + COORDINATES_WARNING,
+        help="coordinates of any location inside the tile",
     )
     parser.add_argument(
         "-t",
@@ -236,7 +234,7 @@ def add_tile_arguments(parser: argparse.ArgumentParser) -> None:
         "-b",
         "--boundary-box",
         help="construct the minimum amount of tiles that cover the requested "
-        "boundary box; " + BOUNDARY_BOX_WARNING,
+        "boundary box",
         metavar="<lon1>,<lat1>,<lon2>,<lat2>",
     )
     parser.add_argument(
@@ -305,7 +303,7 @@ def add_render_arguments(parser: argparse.ArgumentParser) -> None:
         "-b",
         "--boundary-box",
         metavar="<lon1>,<lat1>,<lon2>,<lat2>",
-        help="geo boundary box; " + BOUNDARY_BOX_WARNING,
+        help="geo boundary box",
     )
     parser.add_argument(
         "--cache",
@@ -325,8 +323,7 @@ def add_render_arguments(parser: argparse.ArgumentParser) -> None:
         "-c",
         "--coordinates",
         metavar="<latitude>,<longitude>",
-        help="coordinates of any location inside the tile; "
-        + COORDINATES_WARNING,
+        help="coordinates of any location inside the tile",
     )
     parser.add_argument(
         "-s",