Feature: Add min-size parameter

Add often requested feature. '--min-size 50000' will only include files
above a size of 50kB

src/filter.rs

@@ -7,6 +7,7 @@ use std::path::PathBuf;
 
 pub fn get_biggest(
     top_level_nodes: Vec<Node>,
+    min_size: Option<usize>,
     n: usize,
     depth: usize,
     using_a_filter: bool,
@@ -22,14 +23,14 @@ pub fn get_biggest(
     let mut allowed_nodes = HashSet::new();
 
     allowed_nodes.insert(root.name.as_path());
-    heap = add_children(using_a_filter, &root, depth, heap);
+    heap = add_children(using_a_filter, min_size, &root, depth, heap);
 
     for _ in number_top_level_nodes..n {
         let line = heap.pop();
         match line {
             Some(line) => {
                 allowed_nodes.insert(line.name.as_path());
-                heap = add_children(using_a_filter, line, depth, heap);
+                heap = add_children(using_a_filter, min_size, line, depth, heap);
             }
             None => break,
         }
@@ -39,17 +40,16 @@ pub fn get_biggest(
 
 fn add_children<'a>(
     using_a_filter: bool,
+    min_size: Option<usize>,
     file_or_folder: &'a Node,
     depth: usize,
     mut heap: BinaryHeap<&'a Node>,
 ) -> BinaryHeap<&'a Node> {
     if depth > file_or_folder.depth {
-        heap.extend(
-            file_or_folder
-                .children
-                .iter()
-                .filter(|c| !using_a_filter || c.name.is_file() || c.size > 0),
-        )
+        heap.extend(file_or_folder.children.iter().filter(|c| match min_size {
+            Some(ms) => c.size > ms as u64,
+            None => !using_a_filter || c.name.is_file() || c.size > 0,
+        }))
     }
     heap
 }