initial commit

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "arraydiff"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "arraydiff"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

README.md

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+Your goal in this kata is to implement a difference function, which subtracts
+one list from another and returns the result.
+
+It should remove all values from list a, which are present in list b keeping
+their order.
+
+array_diff(vec![1,2], vec![1]) == vec![2] If a value is present in b, all of its
+occurrences must be removed from the other:
+
+array_diff(vec![1,2,2,2,3], vec![2]) == vec![1,3]
+

src/main.rs

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+#![allow(unused)]
+fn main() {
+    println!();
+    let args = vec![
+        (vec![1,2], vec![1]),
+        (vec![1,2,2], vec![2]),
+        (vec![1,2,2], vec![]),
+        (vec![], vec![1,2]),
+        (vec![1,2,3], vec![1,2]),
+    ];
+
+    for (arg1, arg2) in args {
+        println!("{:?}      \tless {:?} \t leaves {:?}, {:?}, {:?}\n",
+            arg1.clone(),
+            arg2.clone(),
+            array_diff(arg1.clone(), arg2.clone()),
+            not_contains(arg1.clone(), arg2.clone()),
+            retains(arg1, arg2)
+        );
+    };
+
+    println!();
+}
+
+fn array_diff<T: PartialEq + std::fmt::Display + std::fmt::Debug>(a: Vec<T>, b: Vec<T>) -> Vec<T> {
+    a.into_iter()
+        .filter(
+            |i| b.iter().all(|e| *e != *i))
+        .collect::<Vec<T>>()
+}
+
+fn not_contains<T: PartialEq>(a: Vec<T>, b: Vec<T>) -> Vec<T> {
+    a.into_iter().filter(|x| !b.contains(x)).collect()
+}
+
+fn retains<T: PartialEq>(a: Vec<T>, b: Vec<T>) -> Vec<T> {
+    let mut a = a;
+    a.retain(|x| !b.contains(x));
+    a
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn returns_expected() {
+        assert_eq!(array_diff(vec![1,2], vec![1]), vec![2]);
+        assert_eq!(array_diff(vec![1,2,2], vec![1]), vec![2,2]);
+        assert_eq!(array_diff(vec![1,2,2], vec![2]), vec![1]);
+        assert_eq!(array_diff(vec![1,2,2], vec![]), vec![1,2,2]);
+        assert_eq!(array_diff(vec![], vec![1,2]), vec![]);
+        assert_eq!(array_diff(vec![1,2,3], vec![1,2]), vec![3]);
+    }
+}