try:
    import re
except ImportError:
    print("SKIP")
    raise SystemExit

r = re.compile(".+")
m = r.match("abc")
print(m.group(0))
try:
    m.group(1)
except IndexError:
    print("IndexError")

# conversion of re and match to string
str(r)
str(m)

r = re.compile("(.+)1")
m = r.match("xyz781")
print(m.group(0))
print(m.group(1))
try:
    m.group(2)
except IndexError:
    print("IndexError")

r = re.compile(r"\n")
m = r.match("\n")
print(m.group(0))
m = r.match("\\")
print(m)
r = re.compile(r"[\n-\r]")
m = r.match("\n")
print(m.group(0))
r = re.compile(r"[\]]")
m = r.match("]")
print(m.group(0))
print("===")

r = re.compile("[a-cu-z]")
m = r.match("a")
print(m.group(0))
m = r.match("z")
print(m.group(0))
m = r.match("d")
print(m)
m = r.match("A")
print(m)
print("===")

r = re.compile("[^a-cu-z]")
m = r.match("a")
print(m)
m = r.match("z")
print(m)
m = r.match("d")
print(m.group(0))
m = r.match("A")
print(m.group(0))
print("===")

# '-' character within character class block
print(re.match("[-a]+", "-a]d").group(0))
print(re.match("[a-]+", "-a]d").group(0))
print("===")

r = re.compile("o+")
m = r.search("foobar")
print(m.group(0))
try:
    m.group(1)
except IndexError:
    print("IndexError")


m = re.match(".*", "foo")
print(m.group(0))

m = re.search("w.r", "hello world")
print(m.group(0))

m = re.match("a+?", "ab")
print(m.group(0))
m = re.match("a*?", "ab")
print(m.group(0))
m = re.match("^ab$", "ab")
print(m.group(0))
m = re.match("a|b", "b")
print(m.group(0))
m = re.match("a|b|c", "c")
print(m.group(0))

# Case where anchors fail to match
r = re.compile("^b|b$")
m = r.search("abc")
print(m)

try:
    re.compile("*")
except:
    print("Caught invalid regex")

# bytes objects
m = re.match(rb"a+?", b"ab")
print(m.group(0))
print("===")

# escaping
m = re.match(r"a\.c", "a.c")
print(m.group(0) if m else "")
m = re.match(r"a\.b", "abc")
print(m is None)
m = re.match(r"a\.b", "a\\bc")
print(m is None)
m = re.match(r"[a\-z]", "abc")
print(m.group(0))
m = re.match(r"[.\]]*", ".].]a")
print(m.group(0))
m = re.match(r"[.\]+]*", ".]+.]a")
print(m.group(0))
m = re.match(r"[a-f0-9x\-yz]*", "abxcd1-23")
print(m.group(0))
m = re.match(r"[a\\b]*", "a\\aa\\bb\\bbab")
print(m.group(0))
m = re.search(r"[a\-z]", "-")
print(m.group(0))
m = re.search(r"[a\-z]", "f")
print(m is None)
m = re.search(r"[a\]z]", "a")
print(m.group(0))
print(re.compile(r"[-a]").split("foo-bar"))
print(re.compile(r"[a-]").split("foo-bar"))
print(re.compile(r"[ax\-]").split("foo-bar"))
print(re.compile(r"[a\-x]").split("foo-bar"))
print(re.compile(r"[\-ax]").split("foo-bar"))
print("===")

# Module functions take str/bytes/re.
for f in (re.match, re.search):
    print(f(".", "foo").group(0))
    print(f(b".", b"foo").group(0))
    print(f(re.compile("."), "foo").group(0))
    try:
        f(123, "a")
    except TypeError:
        print("TypeError")
print("===")