From 80c9d47399bfc6ba773a40b32de13f460cf18a33 Mon Sep 17 00:00:00 2001
From: Rendo <geometicalplayer@gmail.com>
Date: Sun, 9 Nov 2025 11:58:50 +0500
Subject: [PATCH] Display as text

---
 src/formula.rs  |  3 +++
 src/node/mod.rs | 22 +++++++++++++++++++++-
 src/tests.rs    | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/src/formula.rs b/src/formula.rs
index ca4e186..c9e4833 100644
--- a/src/formula.rs
+++ b/src/formula.rs
@@ -53,4 +53,7 @@ impl Formula {
             self.display_recursion(indent_level + 1, next_nodes);
         }
     }
+    pub fn as_text(&self) -> String {
+        self.tree.as_text()
+    }
 }
diff --git a/src/node/mod.rs b/src/node/mod.rs
index ce00cc6..293a6a0 100644
--- a/src/node/mod.rs
+++ b/src/node/mod.rs
@@ -78,6 +78,26 @@ impl Node {
     pub fn modify_tree(&mut self) -> NodeModifier {
         NodeModifier::from_node(self, None)
     }
+    pub fn as_text(&self) -> String {
+        let mut children_text = "".to_string();
+        if self.children.len() > 0 {
+            for i in 0..self.children.len() {
+                children_text += (&self.children[i]).as_text().as_str();
+                if i < self.children.len() - 1 {
+                    children_text += ",";
+                }
+            }
+        }
+        match &self.handler {
+            NodeHandler::Function {
+                name,
+                function,
+                max_args,
+            } => name.clone() + "(" + children_text.as_str() + ")",
+            NodeHandler::Empty => children_text,
+            _ => self.to_string(),
+        }
+    }
 }
 
 impl fmt::Display for Node {
@@ -93,7 +113,7 @@ impl fmt::Display for Node {
                     max_args,
                 } => name.clone(),
                 NodeHandler::Variable => "X".to_string(),
-                NodeHandler::Empty => "Empty".to_string(),
+                NodeHandler::Empty => "".to_string(),
             }
         )
     }
diff --git a/src/tests.rs b/src/tests.rs
index 234e12b..bfe4de7 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -52,3 +52,40 @@ fn test_branch_sum() {
     let results = formula.run(vec![0f64, 1f64, 2f64, 3f64, 4f64, 5f64]);
     assert_eq!(results, vec![1f64, 2f64, 3f64, 4f64, 5f64, 6f64])
 }
+
+#[test]
+fn test_display_as_text() {
+    let mut formula = Formula::new();
+    assert!(
+        formula
+            .modify_tree()
+            .insert_node(
+                Node::function("sum".to_string(), |inputs| inputs.iter().sum(), None),
+                None
+            )
+            .is_err()
+            == false
+    );
+    assert!(
+        formula
+            .modify_tree()
+            .go_down(0)
+            .add_node(Node::function(
+                "sin".to_string(),
+                |inputs| inputs[0].sin(),
+                Some(1)
+            ))
+            .is_err()
+            == false
+    );
+    assert!(
+        formula
+            .modify_tree()
+            .go_down(0)
+            .go_down(1)
+            .add_node(Node::variable())
+            .is_err()
+            == false
+    );
+    assert_eq!(formula.as_text(), "sum(X,sin(X))".to_string());
+}