June 2018 Update

Task/Amb/Rust/amb.rust

@@ -0,0 +1,44 @@
+use std::ops::Add;
+struct Amb<'a> {
+    list: Vec<Vec<&'a str>>,
+}
+fn main() {
+    let amb = Amb {
+        list: vec![
+            vec!["the", "that", "a"],
+            vec!["frog", "elephant", "thing"],
+            vec!["walked", "treaded", "grows"],
+            vec!["slowly", "quickly"],
+        ],
+    };
+    match amb.do_amb(0, 0 as char) {
+        Some(text) => println!("{}", text),
+        None => println!("Nothing found"),
+    }
+}
+impl<'a> Amb<'a> {
+    fn do_amb(&self, level: usize, last_char: char) -> Option<String> {
+        if self.list.is_empty() {
+            panic!("No word list");
+        }
+        if self.list.len() <= level {
+            return Some(String::new());
+        }
+        let mut res = String::new();
+        let word_list = &self.list[level];
+        for word in word_list {
+            if word.chars().next().unwrap() == last_char || last_char == 0 as char {
+                res = res.add(word).add(" ");
+                let answ = self.do_amb(level + 1, word.chars().last().unwrap());
+                match answ {
+                    Some(x) => {
+                        res = res.add(&x);
+                        return Some(res);
+                    }
+                    None => res.clear(),
+                }
+            }
+        }
+        None
+    }
+}