diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 20f499e..01215c2 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -3,7 +3,7 @@ name: Rust
 on:
   push:
   schedule:
-    - cron:  '0 3 * * *'
+    - cron: '0 3 * * *'
   workflow_dispatch:
     inputs:
       bump:
@@ -26,7 +26,7 @@ jobs:
 
   publish:
     if: "${{ inputs.bump }}"
-    # needs: build
+    needs: build
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
diff --git a/src/grid.rs b/src/grid.rs
new file mode 100644
index 0000000..e3a9bd2
--- /dev/null
+++ b/src/grid.rs
@@ -0,0 +1,136 @@
+//! Parameters grid.
+
+use std::{mem, ops::Deref, slice};
+
+use crate::LatLon;
+
+// const TKY2JGD: Par_ = Par_::from_bytes(include_bytes!("../par/TKY2JGD.in"));
+
+const TKY2JGD_BIN: Bin<4707876> = Bin(*include_bytes!("../par/TKY2JGD.in"));
+
+const TKY2JGD: Grid = TKY2JGD_BIN.to_grid();
+
+// const TKY2JGD_G: GridPar<4707876> = GridPar::new(Bin(*include_bytes!("../par/TKY2JGD.in")));
+
+#[repr(align(4))]
+struct Bin<const N: usize>([u8; N]);
+impl<const N: usize> Bin<N> {
+    const fn to_grid(&self) -> Grid {
+        let data = self.0.as_ptr() as *const Dot;
+        let len = self.0.len() / mem::size_of::<Dot>();
+        let dots = unsafe { slice::from_raw_parts(data, len) };
+        Grid::new(dots)
+    }
+}
+
+// struct GridPar<'a, const N: usize> {
+//     bin: Bin<N>,
+//     grid: Grid<'a>,
+// }
+// impl<const N: usize> GridPar<'_, N> {
+//     const fn new(bin: Bin<N>) -> Self {
+//         let grid = bin.to_grid();
+//         Self { bin, grid }
+//     }
+// }
+
+const TKY2JGD_S: Grid = TKY2JGD_BIN.to_grid();
+
+// pub fn interpolate(&self, bl: LatLon, par: &Par)
+
+// struct Par_ {
+//     bytes: &'static [u8],
+// }
+// impl Par_ {
+//     const fn from_bytes(bytes: &'static [u8]) -> Self {
+//         Self { bytes }
+//     }
+//     fn dots(&self) -> &[Dot] {
+//         let data = self.bytes.as_ptr() as _;
+//         let len = self.bytes.len() / mem::size_of::<Dot>();
+
+//         #[cfg(not(target_endian = "little"))]
+//         compile_error!("compile target must be little endian");
+//         // SAFETY:
+//         // - `len * size_of::<Recod>()` always within length of `data`.
+//         // - `data` has 'static lifetime.
+//         // - `len * size_of::<Recod>()` is smaller than `isize::MAX` statically.
+//         unsafe { slice::from_raw_parts(data, len) }
+//     }
+// }
+// impl From<Par> for &[Dot] {
+//     fn from(value: Par) -> Self {
+//         todo!()
+//     }
+// }
+
+// trait Grid_ {}
+// impl<'a, T: Into<&'a [Dot]>> Grid_ for T {}
+
+struct Grid<'a> {
+    dots: &'a [Dot],
+}
+impl<'a> Grid<'a> {
+    const fn new(dots: &'a [Dot]) -> Self {
+        Self { dots }
+    }
+}
+
+struct Grid_<const N: usize> {
+    dots: [Dot; N],
+}
+impl<const N: usize> Grid_<N> {
+    const fn new(dots: [Dot; N]) -> Self {
+        Self { dots }
+    }
+    // const fn from_bytes<const M: usize>(&self, bytes: [u8; M]) -> Grid_<N> {
+    //     let dots: [Dot; N] = unsafe { mem::transmute(bytes) };
+    //     Grid { dots }
+    // }
+    pub fn interpolate(&self, bl: LatLon) -> LatLon {
+        todo!()
+    }
+    pub fn interpolate_wide(&self, bl: LatLon) -> LatLon {
+        todo!()
+    }
+}
+
+#[derive(Debug)]
+#[repr(C)]
+struct Dot {
+    grid_lat: i16,
+    grid_lon: i16,
+    d_lat_us: i32,
+    d_lon_us: i32,
+}
+impl Dot {
+    // fn to_key(&self) -> MilliSecond {
+    //     MilliSecond(Geodetic {
+    //         lat: i32::from(self.grid_lat) * 30 * 1000,
+    //         lon: i32::from(self.grid_lon) * 45 * 1000,
+    //     })
+    // }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn grid_records() {
+        let records = TKY2JGD.dots;
+        assert_eq!(records.len(), 392323);
+
+        let r = records.last().unwrap();
+        assert_eq!(r.grid_lat, 5463);
+        assert_eq!(r.grid_lon, 3356);
+        assert_eq!(r.d_lat_us, 7875320);
+        assert_eq!(r.d_lon_us, -13995610);
+    }
+
+    #[test]
+    fn grid_interpolate() {
+        let dots = [];
+        let sut = Grid::new(&dots);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 52e0526..36e03e2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-mod par;
+mod grid;
 
 /// 度
 pub type Degree = f64;
diff --git a/src/par.rs b/src/par.rs
deleted file mode 100644
index a2f63a0..0000000
--- a/src/par.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-//! Parameters grid.
-
-use std::{mem, slice};
-
-const TKY2JGD: Table = Table::from_bytes(include_bytes!("../par/TKY2JGD.in"));
-
-struct Table {
-    bytes: &'static [u8],
-}
-impl Table {
-    const fn from_bytes(bytes: &'static [u8]) -> Self {
-        Self { bytes }
-    }
-    const fn records(&self) -> &[Record] {
-        let data = self.bytes.as_ptr() as _;
-        let len = self.bytes.len() / mem::size_of::<Record>();
-
-        #[cfg(not(target_endian = "little"))]
-        compile_error!("target must be little endian");
-        unsafe { slice::from_raw_parts(data, len) }
-    }
-}
-
-#[derive(Debug)]
-#[repr(C)]
-struct Record {
-    grid_lat: i16,
-    grid_lon: i16,
-    d_lat_us: i32,
-    d_lon_us: i32,
-}
-impl Record {
-    // fn to_key(&self) -> MilliSecond {
-    //     MilliSecond(Geodetic {
-    //         lat: i32::from(self.grid_lat) * 30 * 1000,
-    //         lon: i32::from(self.grid_lon) * 45 * 1000,
-    //     })
-    // }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn table_records() {
-        let records = TKY2JGD.records();
-        assert_eq!(records.len(), 392323);
-
-        let r = records.last().unwrap();
-        assert_eq!(r.grid_lat, 5463);
-        assert_eq!(r.grid_lon, 3356);
-        assert_eq!(r.d_lat_us, 7875320);
-        assert_eq!(r.d_lon_us, -13995610);
-    }
-}