From ae1bf26ada1882ed8c4c9033319f24b594b4423e Mon Sep 17 00:00:00 2001
From: Jesse Brault <jbrault@mac.com>
Date: Sat, 23 Nov 2024 17:58:43 -0600
Subject: [PATCH] Initial commit.

---
 .gitignore  |  2 ++
 Cargo.lock  |  7 ++++++
 Cargo.toml  |  6 +++++
 src/main.rs | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 81 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.lock
 create mode 100644 Cargo.toml
 create mode 100644 src/main.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2a0038a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/target
+.idea
\ No newline at end of file
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..4aef62f
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "rust-hash-map"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..21ec434
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "rust-hash-map"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..e0b4ff0
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,66 @@
+struct HashMap<'a, K: PartialEq, V> {
+    table: Vec<Option<Vec<(&'a K, &'a V)>>>,
+    hash_fn: fn(&K) -> usize,
+}
+
+impl<'a, K: PartialEq, V> HashMap<'a, K, V> {
+    fn new(capacity: usize, hash_fn: fn(&K) -> usize) -> Self {
+        HashMap {
+            table: Vec::with_capacity(capacity),
+            hash_fn,
+        }
+    }
+
+    fn put(&mut self, k: &'a K, v: &'a V) {
+        let hash = (self.hash_fn)(&k);
+        let target_index = hash % self.table.capacity();
+        match self.table[target_index].take() {
+            None => {
+                let new_container = vec![(k, v)];
+                self.table.insert(target_index, Some(new_container));
+            },
+            Some(mut container) => {
+                container.push((k, v));
+                self.table.insert(target_index, Some(container));
+            }
+        }
+    }
+
+    fn get(&mut self, k: &K) -> Option<&V> {
+        let hash = (self.hash_fn)(&k);
+        let target_index = hash % self.table.capacity();
+        let container_opt = self.table[target_index].take();
+        if container_opt.is_none() {
+            None
+        } else {
+            let container = container_opt.unwrap();
+            for item in container.iter() {
+                if item.0 == k {
+                    let result = Some(item.1);
+                    self.table[target_index] = Some(container);
+                    return result;
+                }
+            }
+            self.table[target_index] = Some(container);
+            None
+        }
+    }
+}
+
+#[cfg(test)]
+mod hash_map_tests {
+    use super::*;
+
+    #[test]
+    fn simple_put_and_get() {
+        let jesse = String::from("Jesse");
+        let brault = String::from("Brault");
+        let mut map: HashMap<String, String> = HashMap::new(8, |s| s.len());
+        map.put(&jesse, &brault);
+        assert_eq!(map.get(&jesse), Some(&brault));
+    }
+}
+
+fn main() {
+    println!("Hello, world!");
+}