def trie_test_empty_samples():
"""
Nothig is to be returned if we are searching for nothing
"""
empty_trie = Trie([])
assert [] == empty_trie.find_in_string(string.letters)
assert [] == empty_trie.find_in_string(string.digits)
assert [] == empty_trie.find_in_string("".join(chr(i) for i in xrange(1, 256)))
assert [] == empty_trie.find_in_string("a" * 1000000)
def trie_test_empty_string():
"""
In case of searching for an empy substring returns
all occurances of the empty string in a search_in
including one preceding any character of search_in
and one after all characters of search_in string.
If search string is empty itself the latter two are
the same.
"""
trie = Trie([""])
assert [("", 0)] == trie.find_in_string("")
assert [("", i) for i in xrange(11)] == trie.find_in_string("a" * 10)
def trie_test_nested_search():
"""
All nested sequences are returned - not only the
longest match. Nested sequences' return order is
following: for any two matches the one with the
smallest end position is returned first. If two
matches have the same end position - the longest
is returned first.
"""
nested_trie = Trie(["a" * i for i in xrange(1, 11)])
matches = nested_trie.find_in_string("a" * 10)
expected_matches = []
for end_position in xrange(1, 11):
for seq_len in xrange(end_position, 0, -1):
expected_matches.append(("a" * seq_len, end_position - seq_len))
assert expected_matches == matches
same_suffix_strings = ["b" + "a" * i for i in xrange(1, 11)]
same_suffix_trie = Trie(same_suffix_strings)
assert zip(same_suffix_strings, [0] * 10) == same_suffix_trie.find_in_string("b" + "a" * 10)
same_prefix_strings = ["a" * i + "b" for i in xrange(1, 11)]
same_prefix_trie = Trie(same_prefix_strings)
assert zip(reversed(same_prefix_strings), range(10)) == same_prefix_trie.find_in_string("a" * 10 + "b")
