diff --git a/parser/parser.yy b/parser/parser.yy
index de1e62b..55ec6d7 100644
--- a/parser/parser.yy
+++ b/parser/parser.yy
@@ -80,8 +80,54 @@ int yywrap()
 
 %%
 
-program: INT_LITERAL
-       ;
+program_items: /* empty */
+             | program_item program_items
+             ;
+
+program_item: module_declaration
+            | import
+            | variable_declaration
+            | function
+            ;
+
+module_declaration: MODULE module_name SEMICOLON
+                  ;
+
+module_name: IDENTIFIER module_name_more
+           ;
+
+module_name_more: /* empty */
+                | DOT IDENTIFIER module_name_more
+                ;
+
+import: IMPORT import_name SEMICOLON
+      ;
+
+import_name: IDENTIFIER import_name_more
+           ;
+
+import_name_more: /* empty */
+                | DOT import_name_more_more
+                ;
+
+import_name_more_more: IDENTIFIER import_name_more
+                     | STAR
+                     ;
+
+function: type IDENTIFIER LPAREN parameter_list RPAREN LCURLY function_items RCURLY
+        ;
+
+function_items: /* empty */
+              | statement function_items
+              ;
+
+parameter_list: /* empty */
+              | variable_spec parameter_list_more
+              ;
+
+parameter_list_more: /* empty */
+                   | COMMA variable_spec parameter_list_more
+                   ;
 
 primitive_type: BYTE
               | UBYTE
@@ -106,17 +152,38 @@ struct_item: variable_declaration
 variable_declaration: variable_spec SEMICOLON;
                     ;
 
-variable_spec: IDENTIFIER COLON type 
+variable_spec: type IDENTIFIER
              ;
 
 ptr_type: type STAR
         ;
 
+array_type: type LBRACKET RBRACKET
+          ;
+
 type: primitive_type
     | ptr_type
     | struct_type
+    | array_type
+    | IDENTIFIER
     ;
 
+statement: expression SEMICOLON
+         | return_statement SEMICOLON
+         ;
+
+return_statement: RETURN expression
+                ;
+
+expression: assign_expr
+          ;
+
+assign_expr: lvalue ASSIGN expression
+           ;
+
+lvalue: IDENTIFIER
+      ;
+
 %%
 
 void parse(const char * fileName)