common/rust: add Grid type

common/rust/src/grid.rs

@@ -0,0 +1,62 @@
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Error {
+    BadWidth { expected: usize, got: usize },
+}
+
+/// A two-dimensional grid of values.
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Grid<T> {
+    width: usize,
+    height: usize,
+    rows: Vec<Vec<T>>,
+}
+
+impl<T> Grid<T> {
+    /// Creates a new grid with a given `width` and `height`. The data is given as a [`Vec`] of
+    /// rows, each row a [`Vec`] of values.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the given data does not match up with the dimensions.
+    pub fn from_rows(rows: Vec<Vec<T>>) -> Result<Self, Error> {
+        let row_len = rows.get(0).map_or(0, Vec::len);
+        if let Some(err) = rows.iter().map(Vec::len).find_map(|l| {
+            (l != row_len).then_some(Error::BadWidth {
+                expected: row_len,
+                got: l,
+            })
+        }) {
+            return Err(err);
+        }
+
+        Ok(Self {
+            width: rows.get(0).map_or(0, std::vec::Vec::len),
+            height: rows.len(),
+            rows,
+        })
+    }
+
+    pub fn rows(&self) -> impl Iterator<Item = impl Iterator<Item = &T>> {
+        self.rows.iter().map(|row| row.iter())
+    }
+
+    pub fn cols(&self) -> impl Iterator<Item = impl Iterator<Item = &T>> {
+        (0..self.width).map(|i| self.rows.iter().map(move |r| &r[i]))
+    }
+
+    pub fn rows_mut(&mut self) -> impl Iterator<Item = impl Iterator<Item = &mut T>> {
+        self.rows.iter_mut().map(|row| row.iter_mut())
+    }
+
+    /*
+    pub fn cols_mut(&mut self) -> impl Iterator<Item = impl Iterator<Item = &mut T>> {
+        (0..self.width).map(move |i| {
+            self.rows.iter_mut().map(move |r| {
+                let i: usize = i;
+                let x: &mut T = &mut r[i];
+                x
+            })
+        })
+    }
+    */
+}

common/rust/src/lib.rs

@@ -3,6 +3,7 @@
 mod section_range;
 pub mod vec2;
 pub mod vecn;
+pub mod grid;
 
 use std::{mem, path::Path};