|
|
"""Input transformer machinery to support IPython special syntax.
|
|
|
|
|
|
This includes the machinery to recognise and transform ``%magic`` commands,
|
|
|
``!system`` commands, ``help?`` querying, prompt stripping, and so forth.
|
|
|
|
|
|
Added: IPython 7.0. Replaces inputsplitter and inputtransformer which were
|
|
|
deprecated in 7.0.
|
|
|
"""
|
|
|
|
|
|
# Copyright (c) IPython Development Team.
|
|
|
# Distributed under the terms of the Modified BSD License.
|
|
|
|
|
|
from codeop import compile_command
|
|
|
import re
|
|
|
import tokenize
|
|
|
from typing import List, Tuple, Optional, Any
|
|
|
import warnings
|
|
|
|
|
|
_indent_re = re.compile(r'^[ \t]+')
|
|
|
|
|
|
def leading_empty_lines(lines):
|
|
|
"""Remove leading empty lines
|
|
|
|
|
|
If the leading lines are empty or contain only whitespace, they will be
|
|
|
removed.
|
|
|
"""
|
|
|
if not lines:
|
|
|
return lines
|
|
|
for i, line in enumerate(lines):
|
|
|
if line and not line.isspace():
|
|
|
return lines[i:]
|
|
|
return lines
|
|
|
|
|
|
def leading_indent(lines):
|
|
|
"""Remove leading indentation.
|
|
|
|
|
|
If the first line starts with a spaces or tabs, the same whitespace will be
|
|
|
removed from each following line in the cell.
|
|
|
"""
|
|
|
if not lines:
|
|
|
return lines
|
|
|
m = _indent_re.match(lines[0])
|
|
|
if not m:
|
|
|
return lines
|
|
|
space = m.group(0)
|
|
|
n = len(space)
|
|
|
return [l[n:] if l.startswith(space) else l
|
|
|
for l in lines]
|
|
|
|
|
|
class PromptStripper:
|
|
|
"""Remove matching input prompts from a block of input.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
prompt_re : regular expression
|
|
|
A regular expression matching any input prompt (including continuation,
|
|
|
e.g. ``...``)
|
|
|
initial_re : regular expression, optional
|
|
|
A regular expression matching only the initial prompt, but not continuation.
|
|
|
If no initial expression is given, prompt_re will be used everywhere.
|
|
|
Used mainly for plain Python prompts (``>>>``), where the continuation prompt
|
|
|
``...`` is a valid Python expression in Python 3, so shouldn't be stripped.
|
|
|
|
|
|
Notes
|
|
|
-----
|
|
|
|
|
|
If initial_re and prompt_re differ,
|
|
|
only initial_re will be tested against the first line.
|
|
|
If any prompt is found on the first two lines,
|
|
|
prompts will be stripped from the rest of the block.
|
|
|
"""
|
|
|
def __init__(self, prompt_re, initial_re=None):
|
|
|
self.prompt_re = prompt_re
|
|
|
self.initial_re = initial_re or prompt_re
|
|
|
|
|
|
def _strip(self, lines):
|
|
|
return [self.prompt_re.sub('', l, count=1) for l in lines]
|
|
|
|
|
|
def __call__(self, lines):
|
|
|
if not lines:
|
|
|
return lines
|
|
|
if self.initial_re.match(lines[0]) or \
|
|
|
(len(lines) > 1 and self.prompt_re.match(lines[1])):
|
|
|
return self._strip(lines)
|
|
|
return lines
|
|
|
|
|
|
classic_prompt = PromptStripper(
|
|
|
prompt_re=re.compile(r'^(>>>|\.\.\.)( |$)'),
|
|
|
initial_re=re.compile(r'^>>>( |$)')
|
|
|
)
|
|
|
|
|
|
ipython_prompt = PromptStripper(re.compile(r'^(In \[\d+\]: |\s*\.{3,}: ?)'))
|
|
|
|
|
|
def cell_magic(lines):
|
|
|
if not lines or not lines[0].startswith('%%'):
|
|
|
return lines
|
|
|
if re.match(r'%%\w+\?', lines[0]):
|
|
|
# This case will be handled by help_end
|
|
|
return lines
|
|
|
magic_name, _, first_line = lines[0][2:].rstrip().partition(' ')
|
|
|
body = ''.join(lines[1:])
|
|
|
return ['get_ipython().run_cell_magic(%r, %r, %r)\n'
|
|
|
% (magic_name, first_line, body)]
|
|
|
|
|
|
|
|
|
def _find_assign_op(token_line) -> Optional[int]:
|
|
|
"""Get the index of the first assignment in the line ('=' not inside brackets)
|
|
|
|
|
|
Note: We don't try to support multiple special assignment (a = b = %foo)
|
|
|
"""
|
|
|
paren_level = 0
|
|
|
for i, ti in enumerate(token_line):
|
|
|
s = ti.string
|
|
|
if s == '=' and paren_level == 0:
|
|
|
return i
|
|
|
if s in {'(','[','{'}:
|
|
|
paren_level += 1
|
|
|
elif s in {')', ']', '}'}:
|
|
|
if paren_level > 0:
|
|
|
paren_level -= 1
|
|
|
return None
|
|
|
|
|
|
def find_end_of_continued_line(lines, start_line: int):
|
|
|
"""Find the last line of a line explicitly extended using backslashes.
|
|
|
|
|
|
Uses 0-indexed line numbers.
|
|
|
"""
|
|
|
end_line = start_line
|
|
|
while lines[end_line].endswith('\\\n'):
|
|
|
end_line += 1
|
|
|
if end_line >= len(lines):
|
|
|
break
|
|
|
return end_line
|
|
|
|
|
|
def assemble_continued_line(lines, start: Tuple[int, int], end_line: int):
|
|
|
r"""Assemble a single line from multiple continued line pieces
|
|
|
|
|
|
Continued lines are lines ending in ``\``, and the line following the last
|
|
|
``\`` in the block.
|
|
|
|
|
|
For example, this code continues over multiple lines::
|
|
|
|
|
|
if (assign_ix is not None) \
|
|
|
and (len(line) >= assign_ix + 2) \
|
|
|
and (line[assign_ix+1].string == '%') \
|
|
|
and (line[assign_ix+2].type == tokenize.NAME):
|
|
|
|
|
|
This statement contains four continued line pieces.
|
|
|
Assembling these pieces into a single line would give::
|
|
|
|
|
|
if (assign_ix is not None) and (len(line) >= assign_ix + 2) and (line[...
|
|
|
|
|
|
This uses 0-indexed line numbers. *start* is (lineno, colno).
|
|
|
|
|
|
Used to allow ``%magic`` and ``!system`` commands to be continued over
|
|
|
multiple lines.
|
|
|
"""
|
|
|
parts = [lines[start[0]][start[1]:]] + lines[start[0]+1:end_line+1]
|
|
|
return ' '.join([p.rstrip()[:-1] for p in parts[:-1]] # Strip backslash+newline
|
|
|
+ [parts[-1].rstrip()]) # Strip newline from last line
|
|
|
|
|
|
class TokenTransformBase:
|
|
|
"""Base class for transformations which examine tokens.
|
|
|
|
|
|
Special syntax should not be transformed when it occurs inside strings or
|
|
|
comments. This is hard to reliably avoid with regexes. The solution is to
|
|
|
tokenise the code as Python, and recognise the special syntax in the tokens.
|
|
|
|
|
|
IPython's special syntax is not valid Python syntax, so tokenising may go
|
|
|
wrong after the special syntax starts. These classes therefore find and
|
|
|
transform *one* instance of special syntax at a time into regular Python
|
|
|
syntax. After each transformation, tokens are regenerated to find the next
|
|
|
piece of special syntax.
|
|
|
|
|
|
Subclasses need to implement one class method (find)
|
|
|
and one regular method (transform).
|
|
|
|
|
|
The priority attribute can select which transformation to apply if multiple
|
|
|
transformers match in the same place. Lower numbers have higher priority.
|
|
|
This allows "%magic?" to be turned into a help call rather than a magic call.
|
|
|
"""
|
|
|
# Lower numbers -> higher priority (for matches in the same location)
|
|
|
priority = 10
|
|
|
|
|
|
def sortby(self):
|
|
|
return self.start_line, self.start_col, self.priority
|
|
|
|
|
|
def __init__(self, start):
|
|
|
self.start_line = start[0] - 1 # Shift from 1-index to 0-index
|
|
|
self.start_col = start[1]
|
|
|
|
|
|
@classmethod
|
|
|
def find(cls, tokens_by_line):
|
|
|
"""Find one instance of special syntax in the provided tokens.
|
|
|
|
|
|
Tokens are grouped into logical lines for convenience,
|
|
|
so it is easy to e.g. look at the first token of each line.
|
|
|
*tokens_by_line* is a list of lists of tokenize.TokenInfo objects.
|
|
|
|
|
|
This should return an instance of its class, pointing to the start
|
|
|
position it has found, or None if it found no match.
|
|
|
"""
|
|
|
raise NotImplementedError
|
|
|
|
|
|
def transform(self, lines: List[str]):
|
|
|
"""Transform one instance of special syntax found by ``find()``
|
|
|
|
|
|
Takes a list of strings representing physical lines,
|
|
|
returns a similar list of transformed lines.
|
|
|
"""
|
|
|
raise NotImplementedError
|
|
|
|
|
|
class MagicAssign(TokenTransformBase):
|
|
|
"""Transformer for assignments from magics (a = %foo)"""
|
|
|
@classmethod
|
|
|
def find(cls, tokens_by_line):
|
|
|
"""Find the first magic assignment (a = %foo) in the cell.
|
|
|
"""
|
|
|
for line in tokens_by_line:
|
|
|
assign_ix = _find_assign_op(line)
|
|
|
if (assign_ix is not None) \
|
|
|
and (len(line) >= assign_ix + 2) \
|
|
|
and (line[assign_ix+1].string == '%') \
|
|
|
and (line[assign_ix+2].type == tokenize.NAME):
|
|
|
return cls(line[assign_ix+1].start)
|
|
|
|
|
|
def transform(self, lines: List[str]):
|
|
|
"""Transform a magic assignment found by the ``find()`` classmethod.
|
|
|
"""
|
|
|
start_line, start_col = self.start_line, self.start_col
|
|
|
lhs = lines[start_line][:start_col]
|
|
|
end_line = find_end_of_continued_line(lines, start_line)
|
|
|
rhs = assemble_continued_line(lines, (start_line, start_col), end_line)
|
|
|
assert rhs.startswith('%'), rhs
|
|
|
magic_name, _, args = rhs[1:].partition(' ')
|
|
|
|
|
|
lines_before = lines[:start_line]
|
|
|
call = "get_ipython().run_line_magic({!r}, {!r})".format(magic_name, args)
|
|
|
new_line = lhs + call + '\n'
|
|
|
lines_after = lines[end_line+1:]
|
|
|
|
|
|
return lines_before + [new_line] + lines_after
|
|
|
|
|
|
|
|
|
class SystemAssign(TokenTransformBase):
|
|
|
"""Transformer for assignments from system commands (a = !foo)"""
|
|
|
@classmethod
|
|
|
def find(cls, tokens_by_line):
|
|
|
"""Find the first system assignment (a = !foo) in the cell.
|
|
|
"""
|
|
|
for line in tokens_by_line:
|
|
|
assign_ix = _find_assign_op(line)
|
|
|
if (assign_ix is not None) \
|
|
|
and not line[assign_ix].line.strip().startswith('=') \
|
|
|
and (len(line) >= assign_ix + 2) \
|
|
|
and (line[assign_ix + 1].type == tokenize.ERRORTOKEN):
|
|
|
ix = assign_ix + 1
|
|
|
|
|
|
while ix < len(line) and line[ix].type == tokenize.ERRORTOKEN:
|
|
|
if line[ix].string == '!':
|
|
|
return cls(line[ix].start)
|
|
|
elif not line[ix].string.isspace():
|
|
|
break
|
|
|
ix += 1
|
|
|
|
|
|
def transform(self, lines: List[str]):
|
|
|
"""Transform a system assignment found by the ``find()`` classmethod.
|
|
|
"""
|
|
|
start_line, start_col = self.start_line, self.start_col
|
|
|
|
|
|
lhs = lines[start_line][:start_col]
|
|
|
end_line = find_end_of_continued_line(lines, start_line)
|
|
|
rhs = assemble_continued_line(lines, (start_line, start_col), end_line)
|
|
|
assert rhs.startswith('!'), rhs
|
|
|
cmd = rhs[1:]
|
|
|
|
|
|
lines_before = lines[:start_line]
|
|
|
call = "get_ipython().getoutput({!r})".format(cmd)
|
|
|
new_line = lhs + call + '\n'
|
|
|
lines_after = lines[end_line + 1:]
|
|
|
|
|
|
return lines_before + [new_line] + lines_after
|
|
|
|
|
|
# The escape sequences that define the syntax transformations IPython will
|
|
|
# apply to user input. These can NOT be just changed here: many regular
|
|
|
# expressions and other parts of the code may use their hardcoded values, and
|
|
|
# for all intents and purposes they constitute the 'IPython syntax', so they
|
|
|
# should be considered fixed.
|
|
|
|
|
|
ESC_SHELL = '!' # Send line to underlying system shell
|
|
|
ESC_SH_CAP = '!!' # Send line to system shell and capture output
|
|
|
ESC_HELP = '?' # Find information about object
|
|
|
ESC_HELP2 = '??' # Find extra-detailed information about object
|
|
|
ESC_MAGIC = '%' # Call magic function
|
|
|
ESC_MAGIC2 = '%%' # Call cell-magic function
|
|
|
ESC_QUOTE = ',' # Split args on whitespace, quote each as string and call
|
|
|
ESC_QUOTE2 = ';' # Quote all args as a single string, call
|
|
|
ESC_PAREN = '/' # Call first argument with rest of line as arguments
|
|
|
|
|
|
ESCAPE_SINGLES = {'!', '?', '%', ',', ';', '/'}
|
|
|
ESCAPE_DOUBLES = {'!!', '??'} # %% (cell magic) is handled separately
|
|
|
|
|
|
def _make_help_call(target, esc, next_input=None):
|
|
|
"""Prepares a pinfo(2)/psearch call from a target name and the escape
|
|
|
(i.e. ? or ??)"""
|
|
|
method = 'pinfo2' if esc == '??' \
|
|
|
else 'psearch' if '*' in target \
|
|
|
else 'pinfo'
|
|
|
arg = " ".join([method, target])
|
|
|
#Prepare arguments for get_ipython().run_line_magic(magic_name, magic_args)
|
|
|
t_magic_name, _, t_magic_arg_s = arg.partition(' ')
|
|
|
t_magic_name = t_magic_name.lstrip(ESC_MAGIC)
|
|
|
if next_input is None:
|
|
|
return 'get_ipython().run_line_magic(%r, %r)' % (t_magic_name, t_magic_arg_s)
|
|
|
else:
|
|
|
return 'get_ipython().set_next_input(%r);get_ipython().run_line_magic(%r, %r)' % \
|
|
|
(next_input, t_magic_name, t_magic_arg_s)
|
|
|
|
|
|
def _tr_help(content):
|
|
|
"""Translate lines escaped with: ?
|
|
|
|
|
|
A naked help line should fire the intro help screen (shell.show_usage())
|
|
|
"""
|
|
|
if not content:
|
|
|
return 'get_ipython().show_usage()'
|
|
|
|
|
|
return _make_help_call(content, '?')
|
|
|
|
|
|
def _tr_help2(content):
|
|
|
"""Translate lines escaped with: ??
|
|
|
|
|
|
A naked help line should fire the intro help screen (shell.show_usage())
|
|
|
"""
|
|
|
if not content:
|
|
|
return 'get_ipython().show_usage()'
|
|
|
|
|
|
return _make_help_call(content, '??')
|
|
|
|
|
|
def _tr_magic(content):
|
|
|
"Translate lines escaped with a percent sign: %"
|
|
|
name, _, args = content.partition(' ')
|
|
|
return 'get_ipython().run_line_magic(%r, %r)' % (name, args)
|
|
|
|
|
|
def _tr_quote(content):
|
|
|
"Translate lines escaped with a comma: ,"
|
|
|
name, _, args = content.partition(' ')
|
|
|
return '%s("%s")' % (name, '", "'.join(args.split()) )
|
|
|
|
|
|
def _tr_quote2(content):
|
|
|
"Translate lines escaped with a semicolon: ;"
|
|
|
name, _, args = content.partition(' ')
|
|
|
return '%s("%s")' % (name, args)
|
|
|
|
|
|
def _tr_paren(content):
|
|
|
"Translate lines escaped with a slash: /"
|
|
|
name, _, args = content.partition(' ')
|
|
|
return '%s(%s)' % (name, ", ".join(args.split()))
|
|
|
|
|
|
tr = { ESC_SHELL : 'get_ipython().system({!r})'.format,
|
|
|
ESC_SH_CAP : 'get_ipython().getoutput({!r})'.format,
|
|
|
ESC_HELP : _tr_help,
|
|
|
ESC_HELP2 : _tr_help2,
|
|
|
ESC_MAGIC : _tr_magic,
|
|
|
ESC_QUOTE : _tr_quote,
|
|
|
ESC_QUOTE2 : _tr_quote2,
|
|
|
ESC_PAREN : _tr_paren }
|
|
|
|
|
|
class EscapedCommand(TokenTransformBase):
|
|
|
"""Transformer for escaped commands like %foo, !foo, or /foo"""
|
|
|
@classmethod
|
|
|
def find(cls, tokens_by_line):
|
|
|
"""Find the first escaped command (%foo, !foo, etc.) in the cell.
|
|
|
"""
|
|
|
for line in tokens_by_line:
|
|
|
if not line:
|
|
|
continue
|
|
|
ix = 0
|
|
|
ll = len(line)
|
|
|
while ll > ix and line[ix].type in {tokenize.INDENT, tokenize.DEDENT}:
|
|
|
ix += 1
|
|
|
if ix >= ll:
|
|
|
continue
|
|
|
if line[ix].string in ESCAPE_SINGLES:
|
|
|
return cls(line[ix].start)
|
|
|
|
|
|
def transform(self, lines):
|
|
|
"""Transform an escaped line found by the ``find()`` classmethod.
|
|
|
"""
|
|
|
start_line, start_col = self.start_line, self.start_col
|
|
|
|
|
|
indent = lines[start_line][:start_col]
|
|
|
end_line = find_end_of_continued_line(lines, start_line)
|
|
|
line = assemble_continued_line(lines, (start_line, start_col), end_line)
|
|
|
|
|
|
if len(line) > 1 and line[:2] in ESCAPE_DOUBLES:
|
|
|
escape, content = line[:2], line[2:]
|
|
|
else:
|
|
|
escape, content = line[:1], line[1:]
|
|
|
|
|
|
if escape in tr:
|
|
|
call = tr[escape](content)
|
|
|
else:
|
|
|
call = ''
|
|
|
|
|
|
lines_before = lines[:start_line]
|
|
|
new_line = indent + call + '\n'
|
|
|
lines_after = lines[end_line + 1:]
|
|
|
|
|
|
return lines_before + [new_line] + lines_after
|
|
|
|
|
|
_help_end_re = re.compile(r"""(%{0,2}
|
|
|
(?!\d)[\w*]+ # Variable name
|
|
|
(\.(?!\d)[\w*]+)* # .etc.etc
|
|
|
)
|
|
|
(\?\??)$ # ? or ??
|
|
|
""",
|
|
|
re.VERBOSE)
|
|
|
|
|
|
class HelpEnd(TokenTransformBase):
|
|
|
"""Transformer for help syntax: obj? and obj??"""
|
|
|
# This needs to be higher priority (lower number) than EscapedCommand so
|
|
|
# that inspecting magics (%foo?) works.
|
|
|
priority = 5
|
|
|
|
|
|
def __init__(self, start, q_locn):
|
|
|
super().__init__(start)
|
|
|
self.q_line = q_locn[0] - 1 # Shift from 1-indexed to 0-indexed
|
|
|
self.q_col = q_locn[1]
|
|
|
|
|
|
@classmethod
|
|
|
def find(cls, tokens_by_line):
|
|
|
"""Find the first help command (foo?) in the cell.
|
|
|
"""
|
|
|
for line in tokens_by_line:
|
|
|
# Last token is NEWLINE; look at last but one
|
|
|
if len(line) > 2 and line[-2].string == '?':
|
|
|
# Find the first token that's not INDENT/DEDENT
|
|
|
ix = 0
|
|
|
while line[ix].type in {tokenize.INDENT, tokenize.DEDENT}:
|
|
|
ix += 1
|
|
|
return cls(line[ix].start, line[-2].start)
|
|
|
|
|
|
def transform(self, lines):
|
|
|
"""Transform a help command found by the ``find()`` classmethod.
|
|
|
"""
|
|
|
piece = ''.join(lines[self.start_line:self.q_line+1])
|
|
|
indent, content = piece[:self.start_col], piece[self.start_col:]
|
|
|
lines_before = lines[:self.start_line]
|
|
|
lines_after = lines[self.q_line + 1:]
|
|
|
|
|
|
m = _help_end_re.search(content)
|
|
|
if not m:
|
|
|
raise SyntaxError(content)
|
|
|
assert m is not None, content
|
|
|
target = m.group(1)
|
|
|
esc = m.group(3)
|
|
|
|
|
|
# If we're mid-command, put it back on the next prompt for the user.
|
|
|
next_input = None
|
|
|
if (not lines_before) and (not lines_after) \
|
|
|
and content.strip() != m.group(0):
|
|
|
next_input = content.rstrip('?\n')
|
|
|
|
|
|
call = _make_help_call(target, esc, next_input=next_input)
|
|
|
new_line = indent + call + '\n'
|
|
|
|
|
|
return lines_before + [new_line] + lines_after
|
|
|
|
|
|
def make_tokens_by_line(lines:List[str]):
|
|
|
"""Tokenize a series of lines and group tokens by line.
|
|
|
|
|
|
The tokens for a multiline Python string or expression are grouped as one
|
|
|
line. All lines except the last lines should keep their line ending ('\\n',
|
|
|
'\\r\\n') for this to properly work. Use `.splitlines(keeplineending=True)`
|
|
|
for example when passing block of text to this function.
|
|
|
|
|
|
"""
|
|
|
# NL tokens are used inside multiline expressions, but also after blank
|
|
|
# lines or comments. This is intentional - see https://bugs.python.org/issue17061
|
|
|
# We want to group the former case together but split the latter, so we
|
|
|
# track parentheses level, similar to the internals of tokenize.
|
|
|
|
|
|
# reexported from token on 3.7+
|
|
|
NEWLINE, NL = tokenize.NEWLINE, tokenize.NL # type: ignore
|
|
|
tokens_by_line:List[List[Any]] = [[]]
|
|
|
if len(lines) > 1 and not lines[0].endswith(('\n', '\r', '\r\n', '\x0b', '\x0c')):
|
|
|
warnings.warn("`make_tokens_by_line` received a list of lines which do not have lineending markers ('\\n', '\\r', '\\r\\n', '\\x0b', '\\x0c'), behavior will be unspecified")
|
|
|
parenlev = 0
|
|
|
try:
|
|
|
for token in tokenize.generate_tokens(iter(lines).__next__):
|
|
|
tokens_by_line[-1].append(token)
|
|
|
if (token.type == NEWLINE) \
|
|
|
or ((token.type == NL) and (parenlev <= 0)):
|
|
|
tokens_by_line.append([])
|
|
|
elif token.string in {'(', '[', '{'}:
|
|
|
parenlev += 1
|
|
|
elif token.string in {')', ']', '}'}:
|
|
|
if parenlev > 0:
|
|
|
parenlev -= 1
|
|
|
except tokenize.TokenError:
|
|
|
# Input ended in a multiline string or expression. That's OK for us.
|
|
|
pass
|
|
|
|
|
|
|
|
|
if not tokens_by_line[-1]:
|
|
|
tokens_by_line.pop()
|
|
|
|
|
|
|
|
|
return tokens_by_line
|
|
|
|
|
|
|
|
|
def has_sunken_brackets(tokens: List[tokenize.TokenInfo]):
|
|
|
"""Check if the depth of brackets in the list of tokens drops below 0"""
|
|
|
parenlev = 0
|
|
|
for token in tokens:
|
|
|
if token.string in {"(", "[", "{"}:
|
|
|
parenlev += 1
|
|
|
elif token.string in {")", "]", "}"}:
|
|
|
parenlev -= 1
|
|
|
if parenlev < 0:
|
|
|
return True
|
|
|
return False
|
|
|
|
|
|
|
|
|
def show_linewise_tokens(s: str):
|
|
|
"""For investigation and debugging"""
|
|
|
if not s.endswith('\n'):
|
|
|
s += '\n'
|
|
|
lines = s.splitlines(keepends=True)
|
|
|
for line in make_tokens_by_line(lines):
|
|
|
print("Line -------")
|
|
|
for tokinfo in line:
|
|
|
print(" ", tokinfo)
|
|
|
|
|
|
# Arbitrary limit to prevent getting stuck in infinite loops
|
|
|
TRANSFORM_LOOP_LIMIT = 500
|
|
|
|
|
|
class TransformerManager:
|
|
|
"""Applies various transformations to a cell or code block.
|
|
|
|
|
|
The key methods for external use are ``transform_cell()``
|
|
|
and ``check_complete()``.
|
|
|
"""
|
|
|
def __init__(self):
|
|
|
self.cleanup_transforms = [
|
|
|
leading_empty_lines,
|
|
|
leading_indent,
|
|
|
classic_prompt,
|
|
|
ipython_prompt,
|
|
|
]
|
|
|
self.line_transforms = [
|
|
|
cell_magic,
|
|
|
]
|
|
|
self.token_transformers = [
|
|
|
MagicAssign,
|
|
|
SystemAssign,
|
|
|
EscapedCommand,
|
|
|
HelpEnd,
|
|
|
]
|
|
|
|
|
|
def do_one_token_transform(self, lines):
|
|
|
"""Find and run the transform earliest in the code.
|
|
|
|
|
|
Returns (changed, lines).
|
|
|
|
|
|
This method is called repeatedly until changed is False, indicating
|
|
|
that all available transformations are complete.
|
|
|
|
|
|
The tokens following IPython special syntax might not be valid, so
|
|
|
the transformed code is retokenised every time to identify the next
|
|
|
piece of special syntax. Hopefully long code cells are mostly valid
|
|
|
Python, not using lots of IPython special syntax, so this shouldn't be
|
|
|
a performance issue.
|
|
|
"""
|
|
|
tokens_by_line = make_tokens_by_line(lines)
|
|
|
candidates = []
|
|
|
for transformer_cls in self.token_transformers:
|
|
|
transformer = transformer_cls.find(tokens_by_line)
|
|
|
if transformer:
|
|
|
candidates.append(transformer)
|
|
|
|
|
|
if not candidates:
|
|
|
# Nothing to transform
|
|
|
return False, lines
|
|
|
ordered_transformers = sorted(candidates, key=TokenTransformBase.sortby)
|
|
|
for transformer in ordered_transformers:
|
|
|
try:
|
|
|
return True, transformer.transform(lines)
|
|
|
except SyntaxError:
|
|
|
pass
|
|
|
return False, lines
|
|
|
|
|
|
def do_token_transforms(self, lines):
|
|
|
for _ in range(TRANSFORM_LOOP_LIMIT):
|
|
|
changed, lines = self.do_one_token_transform(lines)
|
|
|
if not changed:
|
|
|
return lines
|
|
|
|
|
|
raise RuntimeError("Input transformation still changing after "
|
|
|
"%d iterations. Aborting." % TRANSFORM_LOOP_LIMIT)
|
|
|
|
|
|
def transform_cell(self, cell: str) -> str:
|
|
|
"""Transforms a cell of input code"""
|
|
|
if not cell.endswith('\n'):
|
|
|
cell += '\n' # Ensure the cell has a trailing newline
|
|
|
lines = cell.splitlines(keepends=True)
|
|
|
for transform in self.cleanup_transforms + self.line_transforms:
|
|
|
lines = transform(lines)
|
|
|
|
|
|
lines = self.do_token_transforms(lines)
|
|
|
return ''.join(lines)
|
|
|
|
|
|
def check_complete(self, cell: str):
|
|
|
"""Return whether a block of code is ready to execute, or should be continued
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
source : string
|
|
|
Python input code, which can be multiline.
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
status : str
|
|
|
One of 'complete', 'incomplete', or 'invalid' if source is not a
|
|
|
prefix of valid code.
|
|
|
indent_spaces : int or None
|
|
|
The number of spaces by which to indent the next line of code. If
|
|
|
status is not 'incomplete', this is None.
|
|
|
"""
|
|
|
# Remember if the lines ends in a new line.
|
|
|
ends_with_newline = False
|
|
|
for character in reversed(cell):
|
|
|
if character == '\n':
|
|
|
ends_with_newline = True
|
|
|
break
|
|
|
elif character.strip():
|
|
|
break
|
|
|
else:
|
|
|
continue
|
|
|
|
|
|
if not ends_with_newline:
|
|
|
# Append an newline for consistent tokenization
|
|
|
# See https://bugs.python.org/issue33899
|
|
|
cell += '\n'
|
|
|
|
|
|
lines = cell.splitlines(keepends=True)
|
|
|
|
|
|
if not lines:
|
|
|
return 'complete', None
|
|
|
|
|
|
if lines[-1].endswith('\\'):
|
|
|
# Explicit backslash continuation
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
|
|
|
try:
|
|
|
for transform in self.cleanup_transforms:
|
|
|
if not getattr(transform, 'has_side_effects', False):
|
|
|
lines = transform(lines)
|
|
|
except SyntaxError:
|
|
|
return 'invalid', None
|
|
|
|
|
|
if lines[0].startswith('%%'):
|
|
|
# Special case for cell magics - completion marked by blank line
|
|
|
if lines[-1].strip():
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
else:
|
|
|
return 'complete', None
|
|
|
|
|
|
try:
|
|
|
for transform in self.line_transforms:
|
|
|
if not getattr(transform, 'has_side_effects', False):
|
|
|
lines = transform(lines)
|
|
|
lines = self.do_token_transforms(lines)
|
|
|
except SyntaxError:
|
|
|
return 'invalid', None
|
|
|
|
|
|
tokens_by_line = make_tokens_by_line(lines)
|
|
|
|
|
|
# Bail if we got one line and there are more closing parentheses than
|
|
|
# the opening ones
|
|
|
if (
|
|
|
len(lines) == 1
|
|
|
and tokens_by_line
|
|
|
and has_sunken_brackets(tokens_by_line[0])
|
|
|
):
|
|
|
return "invalid", None
|
|
|
|
|
|
if not tokens_by_line:
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
|
|
|
if tokens_by_line[-1][-1].type != tokenize.ENDMARKER:
|
|
|
# We're in a multiline string or expression
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
|
|
|
newline_types = {tokenize.NEWLINE, tokenize.COMMENT, tokenize.ENDMARKER} # type: ignore
|
|
|
|
|
|
# Pop the last line which only contains DEDENTs and ENDMARKER
|
|
|
last_token_line = None
|
|
|
if {t.type for t in tokens_by_line[-1]} in [
|
|
|
{tokenize.DEDENT, tokenize.ENDMARKER},
|
|
|
{tokenize.ENDMARKER}
|
|
|
] and len(tokens_by_line) > 1:
|
|
|
last_token_line = tokens_by_line.pop()
|
|
|
|
|
|
while tokens_by_line[-1] and tokens_by_line[-1][-1].type in newline_types:
|
|
|
tokens_by_line[-1].pop()
|
|
|
|
|
|
if not tokens_by_line[-1]:
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
|
|
|
if tokens_by_line[-1][-1].string == ':':
|
|
|
# The last line starts a block (e.g. 'if foo:')
|
|
|
ix = 0
|
|
|
while tokens_by_line[-1][ix].type in {tokenize.INDENT, tokenize.DEDENT}:
|
|
|
ix += 1
|
|
|
|
|
|
indent = tokens_by_line[-1][ix].start[1]
|
|
|
return 'incomplete', indent + 4
|
|
|
|
|
|
if tokens_by_line[-1][0].line.endswith('\\'):
|
|
|
return 'incomplete', None
|
|
|
|
|
|
# At this point, our checks think the code is complete (or invalid).
|
|
|
# We'll use codeop.compile_command to check this with the real parser
|
|
|
try:
|
|
|
with warnings.catch_warnings():
|
|
|
warnings.simplefilter('error', SyntaxWarning)
|
|
|
res = compile_command(''.join(lines), symbol='exec')
|
|
|
except (SyntaxError, OverflowError, ValueError, TypeError,
|
|
|
MemoryError, SyntaxWarning):
|
|
|
return 'invalid', None
|
|
|
else:
|
|
|
if res is None:
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
|
|
|
if last_token_line and last_token_line[0].type == tokenize.DEDENT:
|
|
|
if ends_with_newline:
|
|
|
return 'complete', None
|
|
|
return 'incomplete', find_last_indent(lines)
|
|
|
|
|
|
# If there's a blank line at the end, assume we're ready to execute
|
|
|
if not lines[-1].strip():
|
|
|
return 'complete', None
|
|
|
|
|
|
return 'complete', None
|
|
|
|
|
|
|
|
|
def find_last_indent(lines):
|
|
|
m = _indent_re.match(lines[-1])
|
|
|
if not m:
|
|
|
return 0
|
|
|
return len(m.group(0).replace('\t', ' '*4))
|
|
|
|
