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.
+    #[must_use]
+    pub fn from_rows(rows: Vec<Vec<T>>) -> Result<Self, Error> {
+        rows.iter().map(Vec::len).try_reduce(|l1, l2| {
+            if l2 != l1 {
+                Err(Error::BadWidth {
+                    expected: l1,
+                    got: l2,
+                })
+            } else {
+                Ok(l2)
+            }
+        })?;
+
+        Ok(Self {
+            width: rows.get(0).map_or(0, |r| r.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};