|
|
"""Token-related utilities"""
|
|
|
|
|
|
# Copyright (c) IPython Development Team.
|
|
|
# Distributed under the terms of the Modified BSD License.
|
|
|
|
|
|
from collections import namedtuple
|
|
|
from io import StringIO
|
|
|
from keyword import iskeyword
|
|
|
|
|
|
import tokenize
|
|
|
|
|
|
|
|
|
Token = namedtuple('Token', ['token', 'text', 'start', 'end', 'line'])
|
|
|
|
|
|
def generate_tokens(readline):
|
|
|
"""wrap generate_tokens to catch EOF errors"""
|
|
|
try:
|
|
|
for token in tokenize.generate_tokens(readline):
|
|
|
yield token
|
|
|
except tokenize.TokenError:
|
|
|
# catch EOF error
|
|
|
return
|
|
|
|
|
|
def line_at_cursor(cell, cursor_pos=0):
|
|
|
"""Return the line in a cell at a given cursor position
|
|
|
|
|
|
Used for calling line-based APIs that don't support multi-line input, yet.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
cell : str
|
|
|
multiline block of text
|
|
|
cursor_pos : integer
|
|
|
the cursor position
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
(line, offset): (string, integer)
|
|
|
The line with the current cursor, and the character offset of the start of the line.
|
|
|
"""
|
|
|
offset = 0
|
|
|
lines = cell.splitlines(True)
|
|
|
for line in lines:
|
|
|
next_offset = offset + len(line)
|
|
|
if not line.endswith('\n'):
|
|
|
# If the last line doesn't have a trailing newline, treat it as if
|
|
|
# it does so that the cursor at the end of the line still counts
|
|
|
# as being on that line.
|
|
|
next_offset += 1
|
|
|
if next_offset > cursor_pos:
|
|
|
break
|
|
|
offset = next_offset
|
|
|
else:
|
|
|
line = ""
|
|
|
return (line, offset)
|
|
|
|
|
|
def token_at_cursor(cell, cursor_pos=0):
|
|
|
"""Get the token at a given cursor
|
|
|
|
|
|
Used for introspection.
|
|
|
|
|
|
Function calls are prioritized, so the token for the callable will be returned
|
|
|
if the cursor is anywhere inside the call.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
cell : unicode
|
|
|
A block of Python code
|
|
|
cursor_pos : int
|
|
|
The location of the cursor in the block where the token should be found
|
|
|
"""
|
|
|
names = []
|
|
|
tokens = []
|
|
|
call_names = []
|
|
|
|
|
|
offsets = {1: 0} # lines start at 1
|
|
|
for tup in generate_tokens(StringIO(cell).readline):
|
|
|
|
|
|
tok = Token(*tup)
|
|
|
|
|
|
# token, text, start, end, line = tup
|
|
|
start_line, start_col = tok.start
|
|
|
end_line, end_col = tok.end
|
|
|
if end_line + 1 not in offsets:
|
|
|
# keep track of offsets for each line
|
|
|
lines = tok.line.splitlines(True)
|
|
|
for lineno, line in enumerate(lines, start_line + 1):
|
|
|
if lineno not in offsets:
|
|
|
offsets[lineno] = offsets[lineno-1] + len(line)
|
|
|
|
|
|
offset = offsets[start_line]
|
|
|
# allow '|foo' to find 'foo' at the beginning of a line
|
|
|
boundary = cursor_pos + 1 if start_col == 0 else cursor_pos
|
|
|
if offset + start_col >= boundary:
|
|
|
# current token starts after the cursor,
|
|
|
# don't consume it
|
|
|
break
|
|
|
|
|
|
if tok.token == tokenize.NAME and not iskeyword(tok.text):
|
|
|
if names and tokens and tokens[-1].token == tokenize.OP and tokens[-1].text == '.':
|
|
|
names[-1] = "%s.%s" % (names[-1], tok.text)
|
|
|
else:
|
|
|
names.append(tok.text)
|
|
|
elif tok.token == tokenize.OP:
|
|
|
if tok.text == '=' and names:
|
|
|
# don't inspect the lhs of an assignment
|
|
|
names.pop(-1)
|
|
|
if tok.text == '(' and names:
|
|
|
# if we are inside a function call, inspect the function
|
|
|
call_names.append(names[-1])
|
|
|
elif tok.text == ')' and call_names:
|
|
|
call_names.pop(-1)
|
|
|
|
|
|
tokens.append(tok)
|
|
|
|
|
|
if offsets[end_line] + end_col > cursor_pos:
|
|
|
# we found the cursor, stop reading
|
|
|
break
|
|
|
|
|
|
if call_names:
|
|
|
return call_names[-1]
|
|
|
elif names:
|
|
|
return names[-1]
|
|
|
else:
|
|
|
return ''
|
|
|
|
|
|
|
|
|
|
