add .last_index_of and .format_debug ; tag 0.0.13

Author: tiye

Cargo.toml

@@ -1,7 +1,7 @@
 
 [package]
 name = "im_ternary_tree"
-version = "0.0.12"
+version = "0.0.13"
 edition = "2021"
 authors = ["jiyinyiyong <jiyinyiyong@gmail.com>"]
 license = "MIT"

src/lib.rs

@@ -62,6 +62,16 @@ where
     }
   }
 
+  /// items in debug display
+  pub fn format_debug(&self) -> String {
+    let mut s = String::from("(TernaryTreeList debug");
+    for x in self.iter() {
+      s.push_str(&format!(" {:?}", x));
+    }
+    s.push(')');
+    s
+  }
+
   /// get element in list by reference
   /// PERF: recursive function is slower than iterative loop with Cell in bench(using `usize`),
   /// however, Calcit is heavy in cloning(reference though... according real practice),
@@ -90,6 +100,14 @@ where
     }
   }
 
+  /// index of element from end, return 0 if found at last
+  pub fn last_index_of(&self, item: &T) -> Option<usize> {
+    match self {
+      Empty => None,
+      Tree(t) => t.last_index_of(item),
+    }
+  }
+
   /// recursively check structure
   pub fn eq_shape(&self, ys: &Self) -> bool {
     match (self, ys) {

src/tree.rs

@@ -180,6 +180,26 @@ where
     }
   }
 
+  // index from end, returns 0 when item found at end of original list
+  pub fn last_index_of(&self, item: &T) -> Option<usize> {
+    match self {
+      Leaf(value) => {
+        if item == value {
+          Some(0)
+        } else {
+          None
+        }
+      }
+      Branch2 { left, middle, .. } => middle
+        .last_index_of(item)
+        .or_else(|| left.last_index_of(item).map(|pos| pos + middle.len())),
+      Branch3 { left, middle, right, .. } => right
+        .last_index_of(item)
+        .or_else(|| middle.last_index_of(item).map(|pos| pos + right.len()))
+        .or_else(|| left.last_index_of(item).map(|pos| pos + middle.len() + right.len())),
+    }
+  }
+
   /// recursively check structure
   pub fn eq_shape(&self, ys: &Self) -> bool {
     if self.len() != ys.len() {
@@ -1059,7 +1079,11 @@ where
   T: Clone + Display + Eq + PartialEq + Debug + Ord + PartialOrd + Hash,
 {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "TernaryTree[{}, ...]", self.len())
+    write!(f, "(TernaryTree")?;
+    for item in self.into_iter() {
+      write!(f, " {}", item)?;
+    }
+    write!(f, ")")
   }
 }
 

tests/list_tests.rs

@@ -7,7 +7,7 @@ use std::sync::Arc;
 fn init_list() -> Result<(), String> {
   assert_eq!(
     TernaryTreeList::from(&[1, 2, 3, 4]).to_string(),
-    String::from("TernaryTree[4, ...]")
+    String::from("(TernaryTree 1 2 3 4)")
   );
 
   let origin11 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];