interfaces: introduce and use a protocol class for the `charencoding` module
See
f2832de2a46c for details when this was done for the `bdiff` module.
This lets us dump the hack where the `pure` implementation was imported during
the type checking phase to provide signatures for the module methods it
provides. Now the protocol classes are starting to shine, because these methods
are provided by `pure.charencoding` and `cext.parsers`, and references to
`cffi.charencoding` and `cext.charencoding` are forwarded to them as appropriate
by the `policy` module. But none of that matters, as long as the module
returned provides the listed methods.
The interface was copy/pasted from the `pure` module, but `jsonescapeu8fallback`
is omitted because it is accessed from the `pure` module directly when the
escaping fails in the primary module's `jsonescapeu8()`.
/*
* LibXDiff by Davide Libenzi ( File Differential Library )
* Copyright (C) 2003 Davide Libenzi
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/>.
*
* Davide Libenzi <davidel@xmailserver.org>
*
*/
#if !defined(XMACROS_H)
#define XMACROS_H
#define XDL_MIN(a, b) ((a) < (b) ? (a): (b))
#define XDL_MAX(a, b) ((a) > (b) ? (a): (b))
#define XDL_ABS(v) ((v) >= 0 ? (v): -(v))
#define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
#define XDL_ISSPACE(c) (isspace((unsigned char)(c)))
#define XDL_ADDBITS(v,b) ((v) + ((v) >> (b)))
#define XDL_MASKBITS(b) ((1UL << (b)) - 1)
#define XDL_HASHLONG(v,b) (XDL_ADDBITS((unsigned long)(v), b) & XDL_MASKBITS(b))
#define XDL_PTRFREE(p) do { if (p) { xdl_free(p); (p) = NULL; } } while (0)
#define XDL_LE32_PUT(p, v) \
do { \
unsigned char *__p = (unsigned char *) (p); \
*__p++ = (unsigned char) (v); \
*__p++ = (unsigned char) ((v) >> 8); \
*__p++ = (unsigned char) ((v) >> 16); \
*__p = (unsigned char) ((v) >> 24); \
} while (0)
#define XDL_LE32_GET(p, v) \
do { \
unsigned char const *__p = (unsigned char const *) (p); \
(v) = (unsigned long) __p[0] | ((unsigned long) __p[1]) << 8 | \
((unsigned long) __p[2]) << 16 | ((unsigned long) __p[3]) << 24; \
} while (0)
#endif /* #if !defined(XMACROS_H) */