def test_scanner_position():
"""Test scanner line counts and byte offsets"""
lines = [
"foo\n",
"bar\n",
"baz\n",
]
scanner = Scanner(lines)
i = iter(scanner)
# initial position
assert_equals(scanner.position, (0, 0))
i.next()
assert_equals(scanner.position, (1, 0))
token = i.next()
assert_equals(scanner.position, (2, 4))
scanner.push_back(token)
assert_equals(scanner.position, (1, 0))
def test_scanner_pushback():
"""Test scanner push_back"""
lines = [
"foo\n",
"bar\n",
"baz\n",
]
scanner = Scanner(lines)
i = iter(scanner)
first_token = i.next()
assert_equals(first_token, lines[0])
scanner.push_back(first_token)
second_token = i.next()
assert_equals(second_token, first_token)
third_token = i.next()
assert_equals(third_token, lines[1])
fourth_token = i.next()
assert_equals(fourth_token, lines[2])
assert_raises(StopIteration, i.next)
scanner.push_back(fourth_token)
fifth_token = i.next()
assert_equals(fourth_token, fifth_token)
