Ambiguous Alternatives Detected

[Serhioromano]

Another roblem. I have file like this.

grammar StructuredText

entry Document:
    (programs+=Program | functions+=Function | functionb+=FunctionBlock
    | types+=Type)*;

Program:
    'PROGRAM' name=ID 'END_PROGRAM';

FunctionBlock:
    'FUNCTION_BLOCK' name=ID 'END_FUNCTION_BLOCK';

Function:
    'FUNCTION' name=ID ':' return_type=Dtypes 'END_FUNCTION';

Type:
    'TYPE' name=ID  'END_TYPE';

Dtypes:
    'BOOL' | 'SINT' | 'USINT' | 'INT' | 'UINT' | 'DINT' | 'UDINT' | 'LINT' | 'ULINT' | 'REAL'
    | 'LREAL' | 'TIME' | 'TOD' | 'DT' | 'BYTE' | 'WORD' | 'DWORD' | functionblock=[FunctionBlock:ID]  | type=[Type:ID];

terminal ID: /[_a-zA-Z][\w_]*/;

But when I try to generate it shows error

Error: Parser definition errors detected:
-------------------------------
:19 - Ambiguous Alternatives Detected: <18 ,19> in <OR1> inside <Dtypes> Rule,
<ID> may appears as a prefix path in all these alternatives.
See: https://chevrotain.io/docs/guide/resolving_grammar_errors.html#AMBIGUOUS_ALTERNATIVES
For Further details.

Line 19 is the one where Dtypes is. I know that this is because of functionblock=[FunctionBlock:ID] | type=[Type:ID]. If I use only one of those it generates ok. I followed link but unfortunately after reading it few times I still have no Idea how to fix something like this.

[msujew]

So basically the parser complains that it can parse both alternatives using the ID token. You can solve this easily by just merging the reference into a single declaration and referencing that:

FunctionBlock:
    'FUNCTION_BLOCK' name=ID 'END_FUNCTION_BLOCK';

Type:
    'TYPE' name=ID  'END_TYPE';

type Declaration = FunctionBlock | Type;

Dtypes: ... | type=[Declaration :ID];