wkt! macro for compile time checking of static wkt text

...like the serde_json::json! macro.

src/lib.rs

@@ -93,6 +93,7 @@ use crate::types::Polygon;
 
 mod to_wkt;
 mod tokenizer;
+mod wkt_macro;
 
 /// `WKT` primitive types and collections
 pub mod types;
@@ -120,6 +121,7 @@ pub mod deserialize;
 pub use deserialize::deserialize_wkt;
 
 mod from_wkt;
+
 pub use from_wkt::TryFromWkt;
 
 #[cfg(all(feature = "serde", feature = "geo-types"))]

src/wkt_macro.rs

@@ -0,0 +1,302 @@
+/// ```
+/// use wkt::wkt;
+/// let point = wkt::wkt!(POINT(1.0 2.0));
+/// println!("point is: {point}");
+/// ```
+#[macro_export(local_inner_macros)]
+macro_rules! wkt {
+    // Hide distracting implementation details from the generated rustdoc.
+    ($($wkt:tt)+) => {
+        {
+            use $crate::{types::*, Wkt};
+            wkt_internal!($($wkt)+)
+        }
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+macro_rules! wkt_internal {
+    (POINT $tt: tt) => {
+        Wkt::Point(point!($tt))
+    };
+    (LINESTRING $tt: tt) => {
+        Wkt::LineString(line_string!($tt))
+    };
+    (POLYGON $tt:tt) => {
+        Wkt::Polygon(polygon!($tt))
+    };
+    (MULTIPOINT $tt: tt) => {
+        Wkt::MultiPoint(multi_point!($tt))
+    };
+    (MULTILINESTRING $tt: tt) => {
+        Wkt::MultiLineString(multi_line_string!($tt))
+    };
+    (MULTIPOLYGON $tt: tt) => {
+        Wkt::MultiPolygon(multi_polygon!($tt))
+    };
+    (GEOMETRYCOLLECTION $tt: tt) => {
+        Wkt::GeometryCollection(geometry_collection!($tt))
+    };
+}
+
+// Inspired by serde_json::json macro
+#[macro_export]
+#[doc(hidden)]
+macro_rules! point_vec {
+    (@points [$($el:expr),*]) => {
+        // done
+        vec![$($el),*]
+    };
+    (@points [$el:expr]) => {
+        // done
+        vec![$el]
+    };
+
+    // Next element is an expression followed by comma.
+    (@points [$($el:expr,)*] EMPTY, $($rest:tt)*) => {
+        $crate::point_vec!(@points [$($el,)* $crate::point_el!(EMPTY),] $($rest)*)
+    };
+    // Next element is an expression followed by comma.
+    (@points [$($el:expr,)*] $x:literal $y:literal, $($rest:tt)*) => {
+        $crate::point_vec!(@points [$($el,)* $crate::point_el!($x $y),] $($rest)*)
+    };
+
+    (@points [$($el:expr,)*] EMPTY) => {
+        $crate::point_vec!(@points [$($el,)* $crate::point_el!(EMPTY)])
+    };
+    (@points [$($el:expr,)*] $x: literal $y:literal) => {
+        $crate::point_vec!(@points [$($el,)* $crate::point_el!($x $y)])
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! coord {
+    ($x: literal $y: literal) => {
+        Coord {
+            x: $x,
+            y: $y,
+            z: None,
+            m: None,
+        }
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+macro_rules! point_el {
+    (EMPTY) => {
+        Point(None)
+    };
+    ($x: literal $y: literal) => {
+        Point(Some(coord!($x $y)))
+    };
+}
+
+#[macro_export(local_inner_macros)]
+#[doc(hidden)]
+macro_rules! point {
+    (EMPTY) => {
+        point_el!(EMPTY)
+    };
+    (($x: literal $y: literal)) => {
+        point_el!($x $y)
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! line_string {
+    (()) => {
+        compile_error!("use `LINESTRING EMPTY` for a LineString with no coordinates")
+    };
+    (EMPTY) => {
+        LineString(vec![])
+    };
+    (($($x: literal $y: literal),*)) => {
+        LineString(
+            vec![$($crate::coord!($x $y)),*]
+        )
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! polygon {
+    (EMPTY) => {
+        Polygon(vec![])
+    };
+    (()) => {
+        compile_error!("use `POLYGON EMPTY` for a Polygon with no coordinates")
+    };
+    (( $($line_string_tt: tt),* )) => {
+        Polygon(vec![
+           $($crate::line_string![$line_string_tt]),*
+        ])
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! multi_point {
+    (EMPTY) => {
+        MultiPoint(vec![])
+    };
+    (()) => {
+        compile_error!("use `MULTIPOINT EMPTY` for a MultiPoint with no coordinates")
+    };
+    (($($tt: tt)*)) => {
+        MultiPoint(
+            point_vec!(@points [] $($tt)*)
+        )
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! multi_line_string {
+    (EMPTY) => {
+        MultiLineString(vec![])
+    };
+    (()) => {
+        compile_error!("use `MULTILINESTRING EMPTY` for a MultiLineString with no coordinates")
+    };
+    (( $($line_string_tt: tt),* )) => {
+        MultiLineString(vec![
+           $($crate::line_string![$line_string_tt]),*
+        ])
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! multi_polygon{
+    (EMPTY) => {
+        MultiPolygon(vec![])
+    };
+    (()) => {
+        compile_error!("use `MULTIPOLYGON EMPTY` for a MultiPolygon with no coordinates")
+    };
+    (( $($polygon_tt: tt),* )) => {
+        MultiPolygon(vec![
+           $($crate::polygon![$polygon_tt]),*
+        ])
+    };
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! geometry_collection {
+    (EMPTY) => {
+        GeometryCollection(vec![])
+    };
+    (()) => {
+        compile_error!("use `GEOMETRYCOLLECTION EMPTY` for an empty collection")
+    };
+    (( $($el_type:tt $el_tt: tt),* )) => {
+        GeometryCollection(vec![
+           $($crate::wkt_internal!($el_type $el_tt)),*
+        ])
+    };
+}
+
+#[cfg(test)]
+mod test {
+    use crate::Wkt;
+
+    use std::str::FromStr;
+
+    macro_rules! assert_wkt {
+        ($($wkt_tokens: tt)*) => {
+            let wkt_from_str: Wkt<f64> = Wkt::from_str(stringify!($($wkt_tokens)*)).unwrap();
+            assert_eq!(wkt_from_str, wkt!($($wkt_tokens)*));
+        }
+    }
+
+    #[test]
+    fn point() {
+        assert_wkt! { POINT(1.0 2.0) };
+        assert_wkt! { POINT(1.0   2.0) };
+    }
+
+    #[test]
+    fn empty_point() {
+        assert_wkt! { POINT EMPTY };
+    }
+
+    #[test]
+    fn line_string() {
+        assert_wkt! { LINESTRING(1.0 2.0,3.0 4.0) };
+        assert_wkt! { LINESTRING(1.0 2.0, 3.0 4.0) };
+        assert_wkt! { LINESTRING(1.0 2.0) };
+        assert_wkt! { LINESTRING EMPTY };
+        // This fails to compile (as it should)
+        // assert_wkt! { LINESTRING () };
+    }
+
+    #[test]
+    fn empty_polygon() {
+        assert_wkt! { POLYGON EMPTY };
+    }
+
+    #[test]
+    fn polygon() {
+        assert_wkt! { POLYGON((1.0 2.0)) };
+        assert_wkt! { POLYGON((1.0 2.0,3.0 4.0)) };
+        assert_wkt! { POLYGON((1.0 2.0), (1.1 2.1)) };
+        assert_wkt! { POLYGON((1.0 2.0,3.0 4.0), (1.1 2.1,3.1 4.1), (1.2 2.2,3.2 4.2)) };
+        // This fails to compile (as it should)
+        // assert_wkt! { POLYGON(()) }
+    }
+
+    #[test]
+    fn empty_multi_point() {
+        // This fails to compile (as it should)
+        // assert_wkt! { MULTIPOINT() }
+        assert_wkt! { MULTIPOINT EMPTY };
+    }
+
+    #[test]
+    fn multi_point_with_some_empty() {
+        let wkt = wkt!(MULTIPOINT(1.0 2.0, EMPTY));
+        let Wkt::MultiPoint(mp) = wkt else {
+            panic!("expected multipoint")
+        };
+        assert!(mp.0[0].0.is_some());
+        assert!(mp.0[1].0.is_none());
+
+        // This currently fails because the from_str impl doesn't handle a mix of empty points
+        // while the macro behaves correctly. See https://github.com/georust/wkt/issues/111
+        //
+        // assert_wkt! { MULTIPOINT(1.0 2.0, EMPTY) };
+    }
+    #[test]
+    fn multi_point() {
+        assert_wkt! { MULTIPOINT(1.0 2.0) };
+        assert_wkt! { MULTIPOINT(1.0 2.0,3.0 4.0) };
+        assert_wkt! { MULTIPOINT(1.0 2.0,3.0 4.0) };
+    }
+
+    #[test]
+    fn multi_line_string() {
+        assert_wkt! { MULTILINESTRING ((1.0 2.0,3.0 4.0)) }
+        assert_wkt! { MULTILINESTRING ((1.0 2.0,3.0 4.0),(5.0 6.0,7.0 8.0)) }
+        assert_wkt! { MULTILINESTRING EMPTY }
+        assert_wkt! { MULTILINESTRING ((1.0 2.0,3.0 4.0),EMPTY) }
+    }
+
+    #[test]
+    fn multi_line_polygon() {
+        assert_wkt! { MULTIPOLYGON EMPTY }
+        assert_wkt! { MULTIPOLYGON (((1.0 2.0))) }
+        assert_wkt! { MULTIPOLYGON (((1.0 2.0,3.0 4.0), (1.1 2.1,3.1 4.1), (1.2 2.2,3.2 4.2)),((1.0 2.0))) }
+        assert_wkt! { MULTIPOLYGON (((1.0 2.0,3.0 4.0), (1.1 2.1,3.1 4.1), (1.2 2.2,3.2 4.2)), EMPTY) }
+    }
+
+    #[test]
+    fn geometry_collectio() {
+        assert_wkt! { GEOMETRYCOLLECTION EMPTY }
+        assert_wkt! { GEOMETRYCOLLECTION (POINT (40.0 10.0), LINESTRING (10.0 10.0, 20.0 20.0, 10.0 40.0), POLYGON ((40.0 40.0, 20.0 45.0, 45.0 30.0, 40.0 40.0))) }
+    }
+}