"""Extracting and changing portions of the current line

All functions take cursor offset from the beginning of the line and the line of

Python code, and return None, or a tuple of the start index, end index, and the

word."""

from __future__ import unicode_literals

from itertools import chain

from collections import namedtuple

from bpython.lazyre import LazyReCompile

LinePart = namedtuple('LinePart', ['start', 'stop', 'word'])

current_word_re = LazyReCompile(

r'(?<![)\]\w_.])'

r'([\w_][\w0-9._]*[(]?)')

def current_word(cursor_offset, line):

"""the object.attribute.attribute just before or under the cursor"""

pos = cursor_offset

matches = current_word_re.finditer(line)

start = pos

end = pos

word = None

for m in matches:

if m.start(1) < pos and m.end(1) >= pos:

start = m.start(1)

end = m.end(1)

word = m.group(1)

if word is None:

return None

return LinePart(start, end, word)

current_dict_key_re = LazyReCompile(r'''[\w_][\w0-9._]*\[([\w0-9._(), '"]*)''')

def current_dict_key(cursor_offset, line):

"""If in dictionary completion, return the current key"""

matches = current_dict_key_re.finditer(line)

for m in matches:

if m.start(1) <= cursor_offset and m.end(1) >= cursor_offset:

return LinePart(m.start(1), m.end(1), m.group(1))

return None

current_dict_re = LazyReCompile(r'''([\w_][\w0-9._]*)\[([\w0-9._(), '"]*)''')

def current_dict(cursor_offset, line):

"""If in dictionary completion, return the dict that should be used"""

matches = current_dict_re.finditer(line)

for m in matches:

if m.start(2) <= cursor_offset and m.end(2) >= cursor_offset:

return LinePart(m.start(1), m.end(1), m.group(1))

return None

current_string_re = LazyReCompile(

'''(?P<open>(?:""")|"|(?:''\')|')(?:((?P<closed>.+?)(?P=open))|'''

'''(?P<unclosed>.+))''')

def current_string(cursor_offset, line):

"""If inside a string of nonzero length, return the string (excluding

quotes)

Weaker than bpython.Repl's current_string, because that checks that a

string is a string based on previous lines in the buffer."""

for m in current_string_re.finditer(line):

i = 3 if m.group(3) else 4

if m.start(i) <= cursor_offset and m.end(i) >= cursor_offset:

return LinePart(m.start(i), m.end(i), m.group(i))

return None

current_object_re = LazyReCompile(r'([\w_][\w0-9_]*)[.]')

def current_object(cursor_offset, line):

"""If in attribute completion, the object on which attribute should be

looked up."""

match = current_word(cursor_offset, line)

if match is None:

return None

start, end, word = match

matches = current_object_re.finditer(word)

s = ''

for m in matches:

if m.end(1) + start < cursor_offset:

if s:

s += '.'

s += m.group(1)

if not s:

return None

return LinePart(start, start + len(s), s)

current_object_attribute_re = LazyReCompile(r'([\w_][\w0-9_]*)[.]?')

def current_object_attribute(cursor_offset, line):

"""If in attribute completion, the attribute being completed"""

# TODO replace with more general current_expression_attribute

match = current_word(cursor_offset, line)

if match is None:

return None

start, end, word = match

matches = current_object_attribute_re.finditer(word)

next(matches)

for m in matches:

if (m.start(1) + start <= cursor_offset and

m.end(1) + start >= cursor_offset):

return LinePart(m.start(1) + start, m.end(1) + start, m.group(1))

return None

current_from_import_from_re = LazyReCompile(

r'from ([\w0-9_.]*)(?:\s+import\s+([\w0-9_]+[,]?\s*)+)*')

def current_from_import_from(cursor_offset, line):

"""If in from import completion, the word after from

returns None if cursor not in or just after one of the two interesting

parts of an import: from (module) import (name1, name2)

"""

# TODO allow for as's

tokens = line.split()

if not ('from' in tokens or 'import' in tokens):

return None

matches = current_from_import_from_re.finditer(line)

for m in matches:

if ((m.start(1) < cursor_offset and m.end(1) >= cursor_offset) or

(m.start(2) < cursor_offset and m.end(2) >= cursor_offset)):

return LinePart(m.start(1), m.end(1), m.group(1))

return None

current_from_import_import_re_1 = LazyReCompile(r'from\s([\w0-9_.]*)\s+import')

current_from_import_import_re_2 = LazyReCompile(r'([\w0-9_]+)')

current_from_import_import_re_3 = LazyReCompile(r'[,][ ]([\w0-9_]*)')

def current_from_import_import(cursor_offset, line):

"""If in from import completion, the word after import being completed

returns None if cursor not in or just after one of these words

"""

baseline = current_from_import_import_re_1.search(line)

if baseline is None:

return None

match1 = current_from_import_import_re_2.search(line[baseline.end():])

if match1 is None:

return None

matches = current_from_import_import_re_3.finditer(line[baseline.end():])

for m in chain((match1, ), matches):

start = baseline.end() + m.start(1)

end = baseline.end() + m.end(1)

if start < cursor_offset and end >= cursor_offset:

return LinePart(start, end, m.group(1))

return None

current_import_re_1 = LazyReCompile(r'import')

current_import_re_2 = LazyReCompile(r'([\w0-9_.]+)')

current_import_re_3 = LazyReCompile(r'[,][ ]([\w0-9_.]*)')

def current_import(cursor_offset, line):

# TODO allow for multiple as's

baseline = current_import_re_1.search(line)

if baseline is None:

return None

match1 = current_import_re_2.search(line[baseline.end():])

if match1 is None:

return None

matches = current_import_re_3.finditer(line[baseline.end():])

for m in chain((match1, ), matches):

start = baseline.end() + m.start(1)

end = baseline.end() + m.end(1)

if start < cursor_offset and end >= cursor_offset:

return LinePart(start, end, m.group(1))

current_method_definition_name_re = LazyReCompile("def\s+([a-zA-Z_][\w]*)")

def current_method_definition_name(cursor_offset, line):

"""The name of a method being defined"""

matches = current_method_definition_name_re.finditer(line)

for m in matches:

if (m.start(1) <= cursor_offset and m.end(1) >= cursor_offset):

return LinePart(m.start(1), m.end(1), m.group(1))

return None

current_single_word_re = LazyReCompile(r"(?<![.])\b([a-zA-Z_][\w]*)")

def current_single_word(cursor_offset, line):

"""the un-dotted word just before or under the cursor"""

matches = current_single_word_re.finditer(line)

for m in matches:

if m.start(1) <= cursor_offset and m.end(1) >= cursor_offset:

return LinePart(m.start(1), m.end(1), m.group(1))

return None

def current_dotted_attribute(cursor_offset, line):

"""The dotted attribute-object pair before the cursor"""

match = current_word(cursor_offset, line)

if match is None:

return None

start, end, word = match

if '.' in word[1:]:

return LinePart(start, end, word)

current_expression_attribute_re = LazyReCompile(

r'[.]\s*((?:[\w_][\w0-9_]*)|(?:))')

def current_expression_attribute(cursor_offset, line):

"""If after a dot, the attribute being completed"""

# TODO replace with more general current_expression_attribute

matches = current_expression_attribute_re.finditer(line)

for m in matches:

if (m.start(1) <= cursor_offset and m.end(1) >= cursor_offset):

return LinePart(m.start(1), m.end(1), m.group(1))

return None