ref: 6a791a854e1ba78061cd84b19c4c3f6c5ae1128d
dir: /examples/test.peg/
start = body '.' { printf(".\n"); };
body = 'a' { printf("a1 "); } 'b' { printf("ab1 "); }
| 'a' { printf("a2 "); } 'c' { printf("ac2 "); }
| 'a' { printf("a3 "); } ( 'd' { printf("ad3 "); } | 'e' { printf("ae3 "); } )
| 'a' { printf("a4 "); } ( 'f' { printf("af4 "); } 'g' { printf("afg4 "); }
| 'f' { printf("af5 "); } 'h' { printf("afh5 "); } )
| 'a' { printf("a6 "); } ( 'f' &{ printf("af6 ") } 'i' &{ printf("afi6 ") }
| 'f' &{ printf("af7 ") } 'j' &{ printf("afj7 ") } );