only blank some stuff

dont blank comments
dont blank functions

Author: RohanAdwankar

blanks/blanks_config.json

@@ -1,6 +1,6 @@
 {
   "language": "python",
-  "diff": 0.2,
+  "diff": 0.1,
   "problem": null,
   "mode": "random"
 }

blanks/src/problem.rs

@@ -87,14 +87,83 @@ pub fn create_blanked_content(content: &str, diff: f64) -> (String, HashMap<usiz
     let mut blanked_content = content.chars().collect::<Vec<char>>();
     let mut original_chars = HashMap::new();
 
-    // Only replace alphanumeric and some special characters
+    // First identify character positions to protect (comments, function signatures, etc.)
+    let mut protect_indices = Vec::new();
+    let lines: Vec<&str> = content.lines().collect();
+    let mut line_start_indices = Vec::new();
+    
+    // Calculate the starting index of each line
+    let mut current_idx = 0;
+    for line in &lines {
+        line_start_indices.push(current_idx);
+        current_idx += line.len() + 1; // +1 for the newline character
+    }
+    
+    // Process each line to identify protected regions
+    for (line_idx, line) in lines.iter().enumerate() {
+        let line_start = line_start_indices[line_idx];
+        let trimmed = line.trim();
+        
+        // Protect entire lines for these cases:
+        
+        // 1. Comments
+        if trimmed.starts_with('#') || trimmed.starts_with("//") || trimmed.starts_with("/*") {
+            protect_indices.extend(line_start..line_start + line.len());
+            continue;
+        }
+        
+        // 2. Function/method definitions
+        if trimmed.starts_with("def ") || trimmed.starts_with("function ") || 
+           trimmed.starts_with("class ") || trimmed.starts_with("struct ") ||
+           trimmed.starts_with("pub fn ") || trimmed.starts_with("fn ") {
+            protect_indices.extend(line_start..line_start + line.len());
+            continue;
+        }
+        
+        // 3. Function signatures with parameters and return types
+        if (trimmed.contains("(") && trimmed.contains(")")) && 
+            (trimmed.contains(" -> ") || trimmed.contains(") {") || trimmed.contains(") =>")) {
+            protect_indices.extend(line_start..line_start + line.len());
+            continue;
+        }
+        
+        // 4. Parameter declarations with default values
+        if trimmed.contains(" = ") && (trimmed.contains("(") || trimmed.contains(")") || trimmed.contains(",")){
+            protect_indices.extend(line_start..line_start + line.len());
+            continue;
+        }
+        
+        // 5. Import statements/includes
+        if trimmed.starts_with("import ") || trimmed.starts_with("from ") || 
+           trimmed.starts_with("using ") || trimmed.starts_with("include ") ||
+           trimmed.starts_with("require ") || trimmed.starts_with("use ") {
+            protect_indices.extend(line_start..line_start + line.len());
+            continue;
+        }
+    }
+    
+    // Only replace alphanumeric and some special characters that aren't protected
     let replaceable_indices: Vec<usize> = blanked_content.iter().enumerate()
-        .filter(|(_, c)| c.is_alphanumeric() || **c == '=' || **c == '+' || **c == '-' || **c == '*' || **c == '/' || **c == '%')
+        .filter(|(i, c)| {
+            // The character should be replaceable AND not in a protected region
+            (c.is_alphanumeric() || **c == '=' || **c == '+' || **c == '-' || 
+             **c == '*' || **c == '/' || **c == '%') && 
+            !protect_indices.contains(i)
+        })
         .map(|(i, _)| i)
         .collect();
 
-    let num_blanks = (replaceable_indices.len() as f64 * diff) as usize;
-    let indices_to_blank: Vec<usize> = replaceable_indices.choose_multiple(&mut rng, num_blanks).cloned().collect();
+    // Calculate how many blanks to create (but ensure we have enough replaceable items)
+    let num_replaceable = replaceable_indices.len();
+    if num_replaceable == 0 {
+        return (content.to_string(), original_chars); // Nothing to blank
+    }
+    
+    let num_blanks = (num_replaceable as f64 * diff) as usize;
+    
+    // Avoid trying to choose more items than available
+    let actual_blanks = std::cmp::min(num_blanks, num_replaceable);
+    let indices_to_blank: Vec<usize> = replaceable_indices.choose_multiple(&mut rng, actual_blanks).cloned().collect();
 
     for &idx in &indices_to_blank {
         original_chars.insert(idx, blanked_content[idx]);