Add Plane (circular array) implementation w/testing

Refactor the code to use Plane struct instead of Vec<bool>

3 files changed, 209 insertions, 26 deletions

diff --git a/CLI/rust/src/game_of_life.rs b/CLI/rust/src/game_of_life.rs
index 6b52034..96ec3d9 100644
--- a/CLI/rust/src/game_of_life.rs
+++ b/CLI/rust/src/game_of_life.rs
@@ -175,12 +175,13 @@ pub(crate) fn generate(opts: Opts) -> Result<Universe, Error> {
 mod generate {
     use super::*;
     use mocktopus::mocking::*;
+    use crate::game_of_life::universe::Plane;
 
     fn universe_mock(opts: Opts) -> Universe {
         Universe {
             opts,
-            current: vec![vec![]],
-            future: vec![vec![]],
+            current: vec![Plane(vec![])],
+            future: vec![Plane(vec![])],
         }
     }
 
diff --git a/CLI/rust/src/game_of_life/generators/input.rs b/CLI/rust/src/game_of_life/generators/input.rs
index 26c0537..710ac8f 100644
--- a/CLI/rust/src/game_of_life/generators/input.rs
+++ b/CLI/rust/src/game_of_life/generators/input.rs
@@ -1,5 +1,5 @@
 use crate::game_of_life::opts::Opts;
-use crate::game_of_life::universe::Universe;
+use crate::game_of_life::universe::{Universe, Plane};
 use clap::{Error, ErrorKind};
 use curl::easy::Easy;
 use regex::Regex;
@@ -30,8 +30,8 @@ mod new {
     fn universe_mock(opts: Opts) -> Universe {
         Universe {
             opts,
-            current: vec![vec![]],
-            future: vec![vec![]],
+            current: vec![Plane(vec![])],
+            future: vec![Plane(vec![])],
         }
     }
 
@@ -114,11 +114,11 @@ mod generate_file_data {
             universe,
             Universe {
                 opts,
-                future: vec![vec![false; 4]; 3],
+                future: vec![Plane(vec![false; 4]); 3],
                 current: vec![
-                    vec![false, false, true, true],
-                    vec![false, false, true, true],
-                    vec![false, false, false, false],
+                    Plane(vec![false, false, true, true]),
+                    Plane(vec![false, false, true, true]),
+                    Plane(vec![false, false, false, false]),
                 ],
             }
         )
@@ -191,11 +191,11 @@ mod generate_url_data {
             universe,
             Universe {
                 opts,
-                future: vec![vec![false; 4]; 3],
+                future: vec![Plane(vec![false; 4]); 3],
                 current: vec![
-                    vec![false, false, true, true], // <!do
-                    vec![false, true, true, true],  // <htm
-                    vec![false, true, true, true],  // <hea
+                    Plane(vec![false, false, true, true]), // <!do
+                    Plane(vec![false, true, true, true]),  // <htm
+                    Plane(vec![false, true, true, true]),  // <hea
                 ],
             }
         )
@@ -222,11 +222,11 @@ fn populate(opts: Opts, raw_data: String) -> Universe {
         })
         .collect();
 
-    let mut current = vec![vec![false; width]; height];
+    let mut current = vec![Plane(vec![false; width]); height];
 
     for i in 0..height {
         for j in 0..width {
-            current[i][j] = data
+            current[i][j as isize] = data
                 .get(i)
                 .unwrap_or(&vec![])
                 .get(j)
@@ -238,7 +238,7 @@ fn populate(opts: Opts, raw_data: String) -> Universe {
     Universe {
         opts,
         current,
-        future: vec![vec![false; width]; height],
+        future: vec![Plane(vec![false; width]); height],
     }
 }
 
@@ -268,13 +268,13 @@ mod populate {
             universe,
             Universe {
                 opts,
-                future: vec![vec![false; 5]; 5],
+                future: vec![Plane(vec![false; 5]); 5],
                 current: vec![
-                    vec![true, false, true, false, false],
-                    vec![true, false, true, false, false],
-                    vec![true, false, true, false, false],
-                    vec![false, false, false, false, false],
-                    vec![false, false, false, false, false],
+                    Plane(vec![true, false, true, false, false]),
+                    Plane(vec![true, false, true, false, false]),
+                    Plane(vec![true, false, true, false, false]),
+                    Plane(vec![false, false, false, false, false]),
+                    Plane(vec![false, false, false, false, false]),
                 ]
             }
         )
@@ -290,8 +290,8 @@ mod populate {
             universe,
             Universe {
                 opts,
-                future: vec![vec![false; 2]; 2],
-                current: vec![vec![true, false], vec![true, false]]
+                future: vec![Plane(vec![false; 2]); 2],
+                current: vec![Plane(vec![true, false]), Plane(vec![true, false])]
             }
         )
     }
diff --git a/CLI/rust/src/game_of_life/universe.rs b/CLI/rust/src/game_of_life/universe.rs
index 83cb7d7..11912fd 100644
--- a/CLI/rust/src/game_of_life/universe.rs
+++ b/CLI/rust/src/game_of_life/universe.rs
@@ -1,9 +1,191 @@
 use crate::game_of_life::opts::Opts;
+use std::ops::{Index, IndexMut};
+
+/// Implement memeory safe indexing (circular indexing)
+///
+/// When the index is out of bound (being negative or out of bound), the index
+/// will try to fetch the item from the other end of the vector as if it's a
+/// cylinder or circular array
+fn circular_index(mut idx: isize, length: isize) -> usize {
+    while idx.is_negative() {
+        idx += length;
+    }
+    (idx % length) as usize
+}
+
+#[cfg(test)]
+mod circular_index {
+    use super::*;
+
+    #[test]
+    fn negative_index() {
+        assert_eq!(circular_index(-1, 3), 2);
+        assert_eq!(circular_index(-2, 3), 1);
+        assert_eq!(circular_index(-3, 3), 0);
+        assert_eq!(circular_index(-4, 3), 2);
+        assert_eq!(circular_index(-5, 3), 1);
+        assert_eq!(circular_index(-6, 3), 0);
+        assert_eq!(circular_index(-7, 3), 2);
+        assert_eq!(circular_index(-8, 3), 1);
+        assert_eq!(circular_index(-9, 3), 0);
+    }
+
+    #[test]
+    fn positve_index() {
+        assert_eq!(circular_index(0, 3), 0);
+        assert_eq!(circular_index(1, 3), 1);
+        assert_eq!(circular_index(2, 3), 2);
+        assert_eq!(circular_index(3, 3), 0);
+        assert_eq!(circular_index(4, 3), 1);
+        assert_eq!(circular_index(5, 3), 2);
+        assert_eq!(circular_index(6, 3), 0);
+        assert_eq!(circular_index(7, 3), 1);
+        assert_eq!(circular_index(8, 3), 2);
+    }
+}
+
+/// Game of Life universe building blocks (a plane is a circular Vec)
+///
+/// This is used internally in the implementation of the Universe to allow
+/// more readable and safer traversing of the universe blocks
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) struct Plane(pub Vec<bool>);
+
+impl Index<isize> for Plane {
+    type Output = bool;
+    fn index(&self, idx: isize) -> &bool {
+        let len = self.0.len() as isize;
+        &self.0[circular_index(idx, len)]
+    }
+}
+
+impl IndexMut<isize> for Plane {
+    fn index_mut(&mut self, idx: isize) -> &mut Self::Output {
+        let len = self.0.len() as isize;
+        &mut self.0[circular_index(idx, len)]
+    }
+}
+
+#[cfg(test)]
+mod plane {
+    use super::*;
+
+    mod index {
+        use super::*;
+
+        #[test]
+        fn get_element() {
+            let p = Plane(vec![false, false, true, false, false]);
+            assert_eq!(p[0], false);
+            assert_eq!(p[1], false);
+            assert_eq!(p[3], false);
+            assert_eq!(p[4], false);
+
+            assert_eq!(p[-3], true);
+            assert_eq!(p[2], true);
+            assert_eq!(p[7], true);
+        }
+    }
+
+    #[cfg(test)]
+    mod index_mut {
+        use super::*;
+
+        #[test]
+        fn set_negative_index_element() {
+            let mut p = Plane(vec![false, false, false, false, false]);
+            p[-3] = true;
+            assert_eq!(p, Plane(vec![false, false, true, false, false]));
+        }
+
+        #[test]
+        fn set_element() {
+            let mut p = Plane(vec![false, false, false, false, false]);
+            p[2] = true;
+            assert_eq!(p, Plane(vec![false, false, true, false, false]));
+        }
+
+        #[test]
+        fn set_out_of_bound_element() {
+            let mut p = Plane(vec![false, false, false, false, false]);
+            p[7] = true;
+            assert_eq!(p, Plane(vec![false, false, true, false, false]));
+        }
+    }
+}
+
 
 /// Game of Life universe struct for running simulations
 #[derive(Debug, Clone, PartialEq)]
 pub(crate) struct Universe {
     pub opts: Opts,
-    pub current: Vec<Vec<bool>>,
-    pub future: Vec<Vec<bool>>,
+    pub current: Vec<Plane>,
+    pub future: Vec<Plane>,
+}
+
+impl Index<isize> for Universe
+{
+    type Output = Plane;
+    fn index(&self, idx: isize) -> &Plane {
+        let len = self.current.len() as isize;
+        &self.current[circular_index(idx, len)]
+    }
+}
+
+#[cfg(test)]
+mod universe {
+    use super::*;
+
+    mod index {
+        use super::*;
+
+        #[test]
+        fn get_element() {
+            let opts = Opts {
+                seed: 1337,
+                input: None,
+                width: 13,
+                height: 13,
+                live_cell: 'L',
+                dead_cell: 'D',
+                delay: 13,
+            };
+            let u = Universe {
+                opts,
+                current: vec![
+                    Plane(vec![false; 5]),
+                    Plane(vec![false, false, true, false, false]),
+                    Plane(vec![false; 5]),
+                ],
+                future: vec![Plane(vec![])],
+            };
+
+            assert_eq!(u[-3][0], false);
+            assert_eq!(u[-3][1], false);
+            assert_eq!(u[-3][3], false);
+            assert_eq!(u[-3][4], false);
+            assert_eq!(u[0][0], false);
+            assert_eq!(u[0][1], false);
+            assert_eq!(u[0][3], false);
+            assert_eq!(u[0][4], false);
+            assert_eq!(u[2][0], false);
+            assert_eq!(u[2][1], false);
+            assert_eq!(u[2][3], false);
+            assert_eq!(u[2][4], false);
+            assert_eq!(u[5][0], false);
+            assert_eq!(u[5][1], false);
+            assert_eq!(u[5][3], false);
+            assert_eq!(u[5][4], false);
+
+            assert_eq!(u[-2][-3], true);
+            assert_eq!(u[-2][2], true);
+            assert_eq!(u[-2][7], true);
+            assert_eq!(u[1][-3], true);
+            assert_eq!(u[1][2], true);
+            assert_eq!(u[1][7], true);
+            assert_eq!(u[4][-3], true);
+            assert_eq!(u[4][2], true);
+            assert_eq!(u[4][7], true);
+        }
+    }
 }