Add support for var loading in calc and add special syntax for calc

src/ts/parser.ts

@@ -1011,6 +1011,11 @@ const matcher = (p1:string,matcherArg:matcherArg) => {
             let main = p1.substring("datetimeformat".length + 1)
             return dateTimeFormat(main)
         }
+        if(p1.startsWith('? ')){
+            const substring = p1.substring(2)
+
+            return calcString(substring).toString()
+        }
         return null        
     } catch (error) {
         return null   
@@ -1427,6 +1432,9 @@ export function getChatVar(key:string){
     const db = get(DataBase)
     const selectedChar = get(selectedCharID)
     const char = db.characters[selectedChar]
+    if(!char){
+        return 'null'
+    }
     const chat = char.chats[char.chatPage]
     chat.scriptstate = chat.scriptstate ?? {}
     return (chat.scriptstate['$' + key])?.toString() ?? 'null'

src/ts/process/infunctions.ts

@@ -1,3 +1,4 @@
+import { getChatVar } from "../parser";
 
 function toRPN(expression:string) {
     let outputQueue = '';
@@ -60,10 +61,22 @@ function calculateRPN(expression:string) {
         }
     });
 
-    return stack.pop();
+    if(stack.length === 0){
+        return 0
+    }
+
+    return stack.pop()
 }
 
 function executeRPNCalculation(text:string) {
+    text = text.replace(/\$([a-zA-Z0-9_]+)/, (_, p1) => {
+        const v = getChatVar(p1)
+        const parsed = parseFloat(v)
+        if(isNaN(parsed)){
+            return "0"
+        }
+        return parsed.toString()
+    })
     const expression = toRPN(text);
     const evaluated = calculateRPN(expression);
     return evaluated