comparison mercurial/utils/stringutil.py @ 37290:cc5a040fe150

wireproto: syntax for encoding CBOR into frames

We just vendored a library for encoding and decoding the CBOR
data format. While the intent of that vendor was to support state
files, CBOR is really a nice data format. It is extensible and
compact.

I've been feeling dirty inventing my own data formats for
frame payloads. While custom formats can always beat out a generic
format, there is a cost to be paid in terms of implementation,
comprehension, etc. CBOR is compact enough that I'm not too
worried about efficiency loss. I think the benefits of using
a standardized format outweigh rolling our own formats. So
I plan to make heavy use of CBOR in the wire protocol going
forward.

This commit introduces support for encoding CBOR data in frame
payloads to our function to make a frame from a human string.
We do need to employ some low-level Python code in order to
evaluate a string as a Python expression. But other than that,
this should hopefully be pretty straightforward.

Unit tests for this function have been added.

Differential Revision: https://phab.mercurial-scm.org/D2948

37289:5fadc63ac99f

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import codecs
import re as remod
import textwrap

from ..i18n import _

    """Parse s into a boolean.

    If s is not a valid boolean, returns None.
    """
    return _booleans.get(s.lower(), None)

37290:cc5a040fe150

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import __future__
import codecs
import re as remod
import textwrap

from ..i18n import _

    """Parse s into a boolean.

    If s is not a valid boolean, returns None.
    """
    return _booleans.get(s.lower(), None)

def evalpython(s):
    """Evaluate a string containing a Python expression.

    THIS FUNCTION IS NOT SAFE TO USE ON UNTRUSTED INPUT. IT'S USE SHOULD BE
    LIMITED TO DEVELOPER-FACING FUNCTIONALITY.
    """
    globs = {
        r'__builtins__': {
            r'None': None,
            r'False': False,
            r'True': True,
            r'int': int,
            r'set': set,
            r'tuple': tuple,
            # Don't need to expose dict and list because we can use
            # literals.
        },
    }

    # We can't use eval() directly because it inherits compiler
    # flags from this module and we need unicode literals for Python 3
    # compatibility.
    code = compile(s, r'<string>', r'eval',
                   __future__.unicode_literals.compiler_flag, True)
    return eval(code, globs, {})