Added grammar support for alias types

Author: RobertoRoos

src/plcdoc/interpreter.py

@@ -289,6 +289,8 @@ def __init__(self, meta_model: TextXMetaClass, file=None):
                 self._objtype = "struct"
             elif "Union" in type_str:
                 self._objtype = "union"
+            elif "Alias" in type_str:
+                self._objtype = "alias"
             else:
                 raise ValueError(f"Could not categorize type `{type_str}`")
 

src/plcdoc/st_declaration.tx

@@ -42,7 +42,7 @@ TypeDef:
 ;
 
 AnyType:
-    TypeStruct | TypeUnion | TypeEnum
+    TypeStruct | TypeUnion | TypeEnum | TypeAlias
 ;
 
 TypeStruct:
@@ -78,6 +78,13 @@ EnumOption:
     (comment=CommentLine)?
 ;
 
+TypeAlias:
+   base=VariableType
+   CommentAny*
+   // Catch trailing comments here, not at the end of `Variable`
+   ';'
+;
+
 /*
 ---------------------------------------------------
 */

tests/plc_code/T_ALIAS.txt

@@ -1,2 +1,4 @@
-TYPE T_INTERLOCK : WORD;
+TYPE T_INTERLOCK : WORD; END_TYPE
+
+TYPE T_Message : STRING[50];
 END_TYPE

tests/test_plc_project.py

@@ -19,6 +19,7 @@ def test_project_interpret(app, status, warning):
         "program": ["MAIN"],
         "enum": ["E_Error"],
         "struct": ["ST_MyStruct"],
+        "alias": ["T_ALIAS"],
     }
 
     for objtype, objects in expected.items():