small refactor

src/lib.rs

@@ -1,4 +1,5 @@
 pub mod formula;
 pub mod node;
+
 #[cfg(test)]
 mod tests;

src/node/mod.rs

@@ -1,9 +1,9 @@
 use std::fmt;
 
-use crate::node::node_modifier::NodeModifier;
 use handler::*;
+use node_modifier::NodeModifier;
 
-mod handler;
+pub(crate) mod handler;
 pub mod node_modifier;
 
 #[derive(Clone)]

src/node/node_modifier/errors.rs

@@ -0,0 +1,24 @@
+use std::fmt;
+
+use crate::node::Node;
+
+pub enum NodeManipulationError {
+    TooMuchChildren(Node),
+    NotEnoughChildren,
+    ProtectedEmpty,
+    IndexOutOfRange(usize),
+}
+impl fmt::Display for NodeManipulationError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                NodeManipulationError::TooMuchChildren(node) => "Too much children",
+                NodeManipulationError::ProtectedEmpty => "Empty node is protected",
+                NodeManipulationError::NotEnoughChildren => "Not enough children",
+                NodeManipulationError::IndexOutOfRange(index) => "Index out of range",
+            }
+        )
+    }
+}

src/node/node_modifier/mod.rs

@@ -1,33 +1,13 @@
-use std::fmt;
-
 use crate::node::Node;
-use crate::node::NodeHandler;
+use crate::node::handler::NodeHandler;
+use errors::*;
 use rand::random_range;
 
+pub mod errors;
+
 const PICK_STOP_PROBABILITY: u8 = 2;
 const TYPE_CHANGE_PROBABILITY: u8 = 10;
 
-pub enum NodeManipulationError {
-    TooMuchChildren(Node),
-    NotEnoughChildren,
-    ProtectedEmpty,
-    IndexOutOfRange(usize),
-}
-impl fmt::Display for NodeManipulationError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                NodeManipulationError::TooMuchChildren(node) => "Too much children",
-                NodeManipulationError::ProtectedEmpty => "Empty node is protected",
-                NodeManipulationError::NotEnoughChildren => "Not enough children",
-                NodeManipulationError::IndexOutOfRange(index) => "Index out of range",
-            }
-        )
-    }
-}
-
 pub struct NodeModifier<'a> {
     picked_node: &'a mut Node,
     // This looks very monstrous, but it means "vector of functions for node paired with their maximum children count, if it exists"