libbun/libbun2 — pull request #9 by imasahiro (2014-06-10 07:18:54+00:00)
Title: backtrack if some part of peg sequence is not matched

peg:
```
$ cat bug.peg
X = ("#" "x");
Y = ("#" "y");
LIST = <>;
XLIST = X+;
YLIST = Y*;
TopLevel = LIST
```

before:
```
>>> #x#x#y
parsed:
#x#x#: #x#x# ## by peg : null
** uncosumed: 'y' **
hit: 0, miss: 8, object=1, error=0
backtrackCount: 0, backtrackLength: 0

Parsed: #x#x#
#x#x#: #x#x# ## by peg : null
```

after:
```
>>> #x#x#y
parsed:
#x#x#y: #x#x#y ## by peg : null
hit: 0, miss: 8, object=1, error=0
backtrackCount: 1, backtrackLength: 1

Parsed: #x#x#y
#x#x#y: #x#x#y ## by peg : null
```