From 375d7eb95f5a3e6b41e11fc999777d062d99c157 Mon Sep 17 00:00:00 2001
From: Edeth-Baguette <timurth2007@gmail.com>
Date: Mon, 13 Jul 2026 18:06:04 -0700
Subject: [PATCH] fix: collapse_toplevel

incorrect indexes and operation order (div before mult)

co-authored by electria
---
 src/parse.rs | 70 ++++++++++++++++++++++++++--------------------------
 1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/src/parse.rs b/src/parse.rs
index 7b96e33..18dd3c9 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -173,7 +173,7 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) {
             _ => panic!("operator is missing an operand"),
         };
 
-        nodes.remove(operator);
+        nodes.remove(start + operator);
         end -= 1;
     }
     while let Some(operator) = nodes[start..end]
@@ -185,7 +185,7 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) {
             _ => panic!("operator is missing an operand"),
         };
 
-        nodes.remove(operator);
+        nodes.remove(start + operator);
         end -= 1;
     }
 
@@ -204,31 +204,10 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) {
 
         let number = lhs.pow(rhs).complete(PREC);
 
-        nodes.remove(operator - 1);
-        nodes.remove(operator - 1);
+        nodes.remove(start + operator - 1);
+        nodes.remove(start + operator - 1);
         end -= 2;
-        nodes[operator - 1] = Node::Number(number);
-    }
-
-    while let Some(operator) = nodes[start..end]
-        .iter()
-        .position(|n| *n == Node::Operator(Operator::Mult))
-    {
-        let lhs = match &nodes[start..end][operator - 1] {
-            Node::Number(n) => n,
-            _ => panic!("operator is missing an operand"),
-        };
-        let rhs = match &nodes[start..end][operator + 1] {
-            Node::Number(n) => n,
-            _ => panic!("operator is missing an operand"),
-        };
-
-        let number = (lhs * rhs).complete(PREC);
-
-        nodes.remove(operator - 1);
-        nodes.remove(operator - 1);
-        end -= 2;
-        nodes[operator - 1] = Node::Number(number);
+        nodes[start + operator - 1] = Node::Number(number);
     }
 
     while let Some(operator) = nodes[start..end]
@@ -246,10 +225,31 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) {
 
         let number = (lhs / rhs).complete(PREC);
 
-        nodes.remove(operator - 1);
-        nodes.remove(operator - 1);
+        nodes.remove(start + operator - 1);
+        nodes.remove(start + operator - 1);
         end -= 2;
-        nodes[operator - 1] = Node::Number(number);
+        nodes[start + operator - 1] = Node::Number(number);
+    }
+
+    while let Some(operator) = nodes[start..end]
+        .iter()
+        .position(|n| *n == Node::Operator(Operator::Mult))
+    {
+        let lhs = match &nodes[start..end][operator - 1] {
+            Node::Number(n) => n,
+            _ => panic!("operator is missing an operand"),
+        };
+        let rhs = match &nodes[start..end][operator + 1] {
+            Node::Number(n) => n,
+            _ => panic!("operator is missing an operand"),
+        };
+
+        let number = (lhs * rhs).complete(PREC);
+
+        nodes.remove(start + operator - 1);
+        nodes.remove(start + operator - 1);
+        end -= 2;
+        nodes[start + operator - 1] = Node::Number(number);
     }
 
     while let Some(operator) = nodes[start..end]
@@ -267,10 +267,10 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) {
 
         let number = (lhs + rhs).complete(PREC);
 
-        nodes.remove(operator - 1);
-        nodes.remove(operator - 1);
+        nodes.remove(start + operator - 1);
+        nodes.remove(start + operator - 1);
         end -= 2;
-        nodes[operator - 1] = Node::Number(number);
+        nodes[start + operator - 1] = Node::Number(number);
     }
 
     while let Some(operator) = nodes[start..end]
@@ -288,10 +288,10 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) {
 
         let number = (lhs - rhs).complete(PREC);
 
-        nodes.remove(operator - 1);
-        nodes.remove(operator - 1);
+        nodes.remove(start + operator - 1);
+        nodes.remove(start + operator - 1);
         end -= 2;
-        nodes[operator - 1] = Node::Number(number);
+        nodes[start + operator - 1] = Node::Number(number);
     }
 
     if nodes.len() > 1 {