fix: fix empty identifier expr position

kclvm/parser/src/parser/expr.rs

@@ -312,16 +312,45 @@ impl<'a> Parser<'a> {
         };
         // bump .
         self.bump();
-        let attr = self.parse_identifier();
-        Box::new(Node::node(
-            Expr::Selector(SelectorExpr {
-                value,
-                attr,
-                has_question,
-                ctx: ExprContext::Load,
-            }),
-            self.sess.struct_token_loc(lo, self.prev_token),
-        ))
+        match self.token.ident() {
+            Some(_) => {
+                let attr = self.parse_identifier();
+                Box::new(Node::node(
+                    Expr::Selector(SelectorExpr {
+                        value,
+                        attr,
+                        has_question,
+                        ctx: ExprContext::Load,
+                    }),
+                    self.sess.struct_token_loc(lo, self.prev_token),
+                ))
+            }
+            _ => {
+                let attr = Box::new(Node::node(
+                    Identifier {
+                        names: vec!["".to_string()],
+                        pkgpath: "".to_string(),
+                        ctx: ExprContext::Load,
+                    },
+                    (
+                        self.sess.lookup_char_pos(self.token.span.lo()),
+                        self.sess.lookup_char_pos(self.token.span.lo()),
+                    ),
+                ));
+                Box::new(Node::node(
+                    Expr::Selector(SelectorExpr {
+                        value,
+                        attr,
+                        has_question,
+                        ctx: ExprContext::Load,
+                    }),
+                    (
+                        self.sess.lookup_char_pos(lo.span.lo()),
+                        self.sess.lookup_char_pos(self.token.span.lo()),
+                    ),
+                ))
+            }
+        }
     }
 
     /// Syntax:
@@ -2099,7 +2128,18 @@ impl<'a> Parser<'a> {
                 {
                     self.sess
                         .struct_token_error(&[TokenKind::ident_value()], self.token);
-                    names.push("".to_string())
+                    names.push("".to_string());
+                    return Box::new(Node::node(
+                        Identifier {
+                            names,
+                            pkgpath: "".to_string(),
+                            ctx: ExprContext::Load,
+                        },
+                        (
+                            self.sess.lookup_char_pos(self.token.span.lo()),
+                            self.sess.lookup_char_pos(self.token.span.lo()),
+                        ),
+                    ));
                 };
             }
         }

kclvm/tools/src/LSP/src/completion.rs

@@ -45,6 +45,13 @@ fn completion_dot(
     pos: &KCLPos,
     prog_scope: &ProgramScope,
 ) -> Option<lsp_types::CompletionResponse> {
+    // Get the position of trigger_character '.'
+    let pos = &KCLPos {
+        filename: pos.filename.clone(),
+        line: pos.line,
+        column: pos.column.map(|c| c - 1),
+    };
+
     match program.pos_to_stmt(pos) {
         Some(node) => match node.node {
             Stmt::Import(stmt) => completion_for_import(&stmt, pos, prog_scope, program),

kclvm/tools/src/LSP/src/test_data/completion_test/dot/completion.k

@@ -17,3 +17,5 @@ p3 = subpkg.  # complete user module definition
 
 import math
 math.         # complete user module definition
+
+"a".

kclvm/tools/src/LSP/src/tests.rs

@@ -589,14 +589,21 @@ fn completion_test() {
     assert_eq!(got, expect);
     items.clear();
 
+    // test completion for literal str builtin function
     let pos = KCLPos {
         filename: file,
-        line: 22,
-        column: Some(19),
+        line: 21,
+        column: Some(4),
     };
-    assert!(completion(Some('.'), &program, &pos, &prog_scope).is_none());
 
-    items.clear();
+    let got = completion(Some('.'), &program, &pos, &prog_scope).unwrap();
+    let binding = STRING_MEMBER_FUNCTIONS;
+    for k in binding.keys() {
+        items.insert(format!("{}{}", k, "()"));
+    }
+    let expect: CompletionResponse = into_completion_items(&items).into();
+
+    assert_eq!(got, expect);
 }
 
 #[test]