After a parse fails, parse.yy.ast is carrying left overs from the partially successful parse.

[sdawood]

Currently after a parse error, parse.yy.ast is carrying left overs from the partially successful parse.
If the next path string has an identical "correct" prefix or the next path string has the same number of components or more, the bug goes unnoticed.

Example:

test('parser ast is reinitialized after parse() throws', function() {
assert.throws(function() { var path = jp.parse('store.book...') })
var path = jp.parse('$..price');
assert.deepEqual(path, [
{ "expression": { "type": "root", "value": "$" } },
{ "expression": { "type": "identifier", "value": "price" }, "operation": "member", "scope": "descendant"}
])
});

// Notice left-over component: { expression: { type: 'identifier', value: 'book' }, ... }

1. parse-negative parser ast is reinitialized after parse() throws:
   AssertionError: [ { expression: { type: 'root', value: '$' } },
   { expression: { type: 'identifier', value: 'book' },
   scope: 'child',
   o deepEqual [ { expression: { type: 'root', value: '$' } },
   { expression: { type: 'identifier', value: 'price' },
   operation: 'member',

[sdawood]

Problem still persists, pull request #10 would pass the tests but doesn't fit well with the JSONPath instance design