trailing comma for tuple implemented

jac/jaclang/compiler/jac.lark

@@ -364,9 +364,9 @@ index_slice: LSQUARE expression? COLON expression? (COLON expression?)? RSQUARE
 // Function calls
 atomic_call: atomic_chain LPAREN param_list? (KW_BY atomic_call)? RPAREN
 
-param_list: expr_list COMMA kw_expr_list
-          | kw_expr_list
-          | expr_list
+param_list: expr_list COMMA kw_expr_list COMMA?
+          | kw_expr_list COMMA?
+          | expr_list COMMA?
 
 // Atom
 atom: named_ref
@@ -421,11 +421,11 @@ kv_pair: expression COLON expression | STAR_POW expression
 expr_list: (expr_list COMMA)? expression
 
 // Tuples and Jac Tuples
-tuple_list: expression COMMA expr_list COMMA kw_expr_list
-          | expression COMMA kw_expr_list
-          | expression COMMA expr_list
+tuple_list: expression COMMA expr_list COMMA kw_expr_list COMMA?
+          | expression COMMA kw_expr_list COMMA?
+          | expression COMMA expr_list COMMA?
           | expression COMMA
-          | kw_expr_list
+          | kw_expr_list COMMA?
 
 kw_expr_list: (kw_expr_list COMMA)? kw_expr
 kw_expr: named_ref EQ expression | STAR_POW expression

jac/jaclang/compiler/parser.py

@@ -2813,25 +2813,37 @@ def tuple_list(
         ) -> ast.SubNodeList[ast.Expr | ast.KWPair]:
             """Grammar rule.
 
-            tuple_list: expression COMMA expr_list COMMA kw_expr_list
-                    | expression COMMA kw_expr_list
-                    | expression COMMA expr_list
-                    | expression COMMA
-                    | kw_expr_list
+            tuple_list: expression COMMA expr_list    COMMA kw_expr_list COMMA?
+                      | expression COMMA kw_expr_list COMMA?
+                      | expression COMMA expr_list    COMMA?
+                      | expression COMMA
+                      | kw_expr_list COMMA?
             """
             chomp = [*kid]
             first_expr = None
             if isinstance(chomp[0], ast.SubNodeList):
+                # The chomp will be like this:
+                #     kw_expr_list, [COMMA]
+                if len(chomp) > 1:
+                    # Add the comma to the subnode list if it exists, otherwise the last comma will not be a part of
+                    # the ast, we need it for formatting.
+                    chomp[0].kid.append(chomp[1])
                 return self.nu(chomp[0])
             else:
-                first_expr = chomp[0]
-                chomp = chomp[2:]
+                # The chomp will be like this:
+                #     expression, COMMA, [subnode_list, [COMMA, [kw_expr_list, [COMMA]]]]
+                # Pop the first expression from chomp.
+                first_expr = chomp[0]   # Get the first expression.
+                chomp = chomp[2:]       # Get rid of expr and comma.
+
+            # The chomp will be like this:
+            #     [subnode_list, [COMMA, [kw_expr_list, [COMMA]]]]
             expr_list = []
             if len(chomp):
-                expr_list = chomp[0].kid
-                chomp = chomp[1:]
+                expr_list = chomp[0].kid  # Get the kids subnode list.
+                chomp = chomp[2:]         # Get rid of the subnode list and a comma if exists.
                 if len(chomp):
-                    chomp = chomp[1:]
+                    # The chomp will be like this: [kw_expr_list, [COMMA]]
                     expr_list = [*expr_list, *chomp[0].kid]
             expr_list = [first_expr, *expr_list]
             valid_kid = [i for i in expr_list if isinstance(i, (ast.Expr, ast.KWPair))]
@@ -2984,12 +2996,16 @@ def param_list(
         ) -> ast.SubNodeList[ast.Expr | ast.KWPair]:
             """Grammar rule.
 
-            param_list: expr_list COMMA kw_expr_list
-                    | kw_expr_list
-                    | expr_list
+            param_list: expr_list    COMMA kw_expr_list COMMA?
+                      | kw_expr_list COMMA?
+                      | expr_list    COMMA?
             """
-            if len(kid) == 1:
+            ends_with_comma = (len(kid) > 1 and isinstance(kid[-1], ast.Token)
+                               and kid[-1].name == 'COMMA')
+            if len(kid) == 1 or (len(kid) == 2 and ends_with_comma):
                 if isinstance(kid[0], ast.SubNodeList):
+                    if ends_with_comma:  # Append the trailing comma to the subnode list.
+                        kid[0].kid.append(kid[1])
                     return self.nu(kid[0])
                 else:
                     raise self.ice()

jac/main.py

@@ -0,0 +1,28 @@
+from jaclang.utils.test import TestCase
+from jaclang.vendor.pygls import uris
+from jaclang.vendor.pygls.workspace import Workspace
+from jaclang.langserve.engine import JacLangServer
+import lsprotocol.types as lspt
+
+
+lsp = JacLangServer()
+workspace_path = "."
+workspace = Workspace(workspace_path, lsp)
+lsp.lsp._workspace = workspace
+import_file = uris.from_fs_path(
+    "c:\\Users\\Thakee\\Desktop\\Home\\jaseci\\jaseci\\jac\\jaclang\\tests\\fixtures\\index_slice.jac"
+)
+lsp.deep_check(import_file)
+positions = [
+    (23, 20, "index_slice.jac:2:8-2:13"),
+    (24, 24, "index_slice.jac:2:8-2:13"),
+    (27, 33, "index_slice.jac:2:8-2:13"),
+]
+
+for line, char, expected in positions:
+    print(str(lsp.get_definition(import_file, lspt.Position(line, char))))
+    assert (
+        expected in
+        str(lsp.get_definition(import_file, lspt.Position(line, char)))
+    )
+