chore: add ModuleEntry.ast

crates/erg_parser/ast.rs

@@ -4966,7 +4966,7 @@ impl Module {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct AST {
     pub name: Str,
     pub module: Module,

crates/erg_parser/parse.rs

@@ -116,6 +116,12 @@ impl Parsable for SimpleParser {
     }
 }
 
+impl SimpleParser {
+    pub fn parse(code: String) -> Result<CompleteArtifact, IncompleteArtifact> {
+        <Self as Parsable>::parse(code)
+    }
+}
+
 enum ExprOrOp {
     Expr(Expr),
     Op(Token),