feat: add molang package

1. upgrade bukkit chat
2. fix config update error

Signed-off-by: MiaoWoo <admin@yumc.pw>

packages/molang/src/parser/expressions/contextSwitch.ts

@@ -0,0 +1,48 @@
+import { ExecutionEnvironment } from '../../env/env'
+import { Expression, IExpression } from '../expression'
+import { NameExpression } from './name'
+
+export class ContextSwitchExpression extends Expression {
+	type = 'NameExpression'
+
+	constructor(
+		protected leftExpr: NameExpression,
+		protected rightExpr: NameExpression
+	) {
+		super()
+	}
+
+	get allExpressions() {
+		return [this.leftExpr, this.rightExpr]
+	}
+	setExpressionAt(index: number, expr: IExpression) {
+		if (!(expr instanceof NameExpression))
+			throw new Error(
+				`Cannot use context switch operator "->" on ${expr.type}`
+			)
+
+		if (index === 0) this.leftExpr = expr
+		else if (index === 1) this.rightExpr = expr
+	}
+
+	isStatic() {
+		return false
+	}
+
+	eval() {
+		const context = this.leftExpr.eval()
+		if (typeof context !== 'object') return 0
+
+		this.rightExpr.setExecutionEnv(
+			new ExecutionEnvironment(
+				context,
+				this.rightExpr.executionEnv.config
+			)
+		)
+		return this.rightExpr.eval()
+	}
+
+	toString() {
+		return `${this.leftExpr.toString()}->${this.rightExpr.toString()}`
+	}
+}