antlr/antlr4 — Issue #7: Prediction can return incorrect results when alts are partially predicated
Author: sharwell
Created: 2012-02-09 07:17:18+00:00
State: open

The following example grammar is used for the TestSemPredEvalParser.testUnpredicatedPathsInAlt unit test.

When started at rule `s` with the input `x 4`, it should predict alt 1.

```
grammar T;
s : a {System.out.println("alt 1");}
| b {System.out.println("alt 2");}
;
a : {false}? ID INT
| ID INT
;
b : ID ID
;
ID : 'a'..'z'+ ;
INT : '0'..'9'+;
WS : (' '|'\n') {skip();} ;
```