Parser now creates lists only when it is necessary

ParadoxSaveParser.CLI/Modes/Search.cs

@@ -38,7 +38,7 @@ internal static partial class Modes
             var parser = new SaveParserEU4(inputStream, searchExpression);
             var parsedValue = parser.Parse();
             JsonSerializer.Serialize(outputStream, parsedValue,
-                ParsedValueJsonContext.Default.DictionaryStringListObject);
+                ParsedValueJsonContext.Default.DictionaryStringObject);
             outputStream.WriteByte((byte)'\n');
         }
         finally

ParadoxSaveParser.Lib/ParsedValueJsonContext.cs

@@ -3,7 +3,7 @@
 namespace ParadoxSaveParser.Lib;
 
 [JsonSourceGenerationOptions(MaxDepth = 1024, WriteIndented = true)]
-[JsonSerializable(typeof(Dictionary<string, List<object>>))]
+[JsonSerializable(typeof(Dictionary<string, object>))]
 [JsonSerializable(typeof(List<object>))]
 [JsonSerializable(typeof(string))]
 [JsonSerializable(typeof(long))]

ParadoxSaveParser.Lib/SaveParserEU4.cs

@@ -216,7 +216,7 @@ public class SaveParserEU4
     }
 
     private static bool IsEmptyCollection(object value)
-        => value is Dictionary<string, List<object>> { Count: 0 } or List<object> { Count: 0 };
+        => value is Dictionary<string, object> { Count: 0 } or List<object> { Count: 0 };
 
     // doesn't move next
     private object ParseListOrDict()
@@ -264,9 +264,9 @@ public class SaveParserEU4
     }
 
     // moves next
-    private Dictionary<string, List<object>> ParseDict()
+    private Dictionary<string, object> ParseDict()
     {
-        Dictionary<string, List<object>> dict = new();
+        Dictionary<string, object> dict = new();
 
         // root is a dict without closing bracket, so this method must check _tokenIndex < _tokens.Count
         for (int localIndex = 0; _tokens.MoveNext(); localIndex++)
@@ -327,23 +327,32 @@ public class SaveParserEU4
 
             string keyStr = keySB.ToString();
             _stringBuilderPool.Return(keySB);
-            if (!dict.TryGetValue(keyStr, out var list))
-            {
-                list = new List<object>();
-                dict.Add(keyStr, list);
-            }
-
             
-            // do dot add empty collections into list
-            if (IsEmptyCollection(value))
-                continue;
-            list.Add(value);
+            // Paradox save format has another way of defining list:
+            // a = 1
+            // a = 2
+            // It means `a = { 1 2 }`
+            if (dict.TryGetValue(keyStr, out var firstValue))
+            {
+                // Do dot add empty collections into list.
+                // `key:{}` is okay, but i don't want to see `key:[{},{},{},{},{},{}]`
+                if (IsEmptyCollection(value))
+                    continue;
+                
+                if (firstValue is List<object> existingList)
+                    existingList.Add(value);
+                else dict[keyStr] = new List<object> { firstValue, value };
+            }
+            else
+            {
+                dict.Add(keyStr, value);
+            }
         }
 
         return dict;
     }
 
-    public Dictionary<string, List<object>> Parse()
+    public Dictionary<string, object> Parse()
     {
         var root = ParseDict();
         return root;

ParadoxSaveParser.WebAPI/SaveDataFilters/ISaveDataFilter.cs

@@ -5,5 +5,5 @@ public interface ISaveDataFilter
     public string SearchString { get; }
     public ISearchExpression SearchExpression { get; }
     
-    public void Apply(Dictionary<string, List<object>> data);
+    public void Apply(Dictionary<string, object> data);
 }

ParadoxSaveParser.WebAPI/SaveDataFilters/SaveFilterEU4.cs

@@ -1,5 +1,5 @@
 using System.Linq;
-using ParsedDict = System.Collections.Generic.Dictionary<string, System.Collections.Generic.List<object>>;
+using ParsedDict = System.Collections.Generic.Dictionary<string, object>;
 
 namespace ParadoxSaveParser.WebAPI.SaveDataFilters;
 
@@ -38,12 +38,11 @@ public class SaveDataFilterEU4 : ISaveDataFilter
     
     public void Apply(ParsedDict data)
     {
-        var countries = (ParsedDict)data["countries"][0];
+        var countries = (ParsedDict)data["countries"];
         var countries_filtered = countries.Where(pair 
-            => pair.Value.Count > 0 
-               && ((ParsedDict)pair.Value[0]).TryGetValue("raw_development", out var raw_development)
-               && (double)raw_development[0] > 0
+            => ((ParsedDict)pair.Value).TryGetValue("raw_development", out var raw_development)
+               && (double)raw_development > 0
             ).ToDictionary();
-        data["countries"][0] = countries_filtered;
+        data["countries"] = countries_filtered;
     }
 }