mdw@git.distorted.org.uk Git - mLib-python/blob - mapping.pyx

   1 ### -*-pyrex-*-
   2 ###
   3 ### Common mapping stuff
   4 ###
   5 ### (c) 2005 Straylight/Edgeware
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This file is part of the Python interface to mLib.
  11 ###
  12 ### mLib/Python is free software; you can redistribute it and/or modify
  13 ### it under the terms of the GNU General Public License as published by
  14 ### the Free Software Foundation; either version 2 of the License, or
  15 ### (at your option) any later version.
  16 ###
  17 ### mLib/Python is distributed in the hope that it will be useful,
  18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ### GNU General Public License for more details.
  21 ###
  22 ### You should have received a copy of the GNU General Public License
  23 ### along with mLib/Python; if not, write to the Free Software Foundation,
  24 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 cdef class Mapping
  27
  28 cdef class _MapIterator:
  29   cdef void *_next(me):
  30     return NULL
  31
  32 cdef class Mapping:
  33
  34   ## Subclasses must implement these
  35   cdef int _init(me) except -1:
  36     raise TypeError, 'abstract class'
  37   cdef void *_find(me, object key, unsigned *f) except NULL:
  38     raise SystemError, 'unimplemented _find'
  39   cdef object _key(me, void *e):
  40     return None
  41   cdef object _value(me, void *e):
  42     return None
  43   cdef void _setval(me, void *e, object val):
  44     pass
  45   cdef void _del(me, void *e):
  46     pass
  47   cdef _MapIterator _iter(me):
  48     raise SystemError, 'unimplemented _iter'
  49
  50   ## Initialization
  51   def __cinit__(me, *hunoz, **hukairz):
  52     me._init()
  53   def __init__(me, stuff = None, **kw):
  54     me.update(stuff, kw)
  55
  56   ## Bulk update
  57   def update(me, stuff = None, **kw):
  58     """D.update([MAP], **KW): insert mappings from MAP and KW"""
  59     cdef unsigned f
  60     if stuff is None:
  61       pass
  62     elif hasattr(stuff, 'itemiter'):
  63       for k, v in stuff.itemiter:
  64         me._setval(me._find(k, &f), v)
  65     elif hasattr(stuff, 'keys'):
  66       for k in stuff.keys():
  67         me._setval(me._find( k, &f), stuff[k])
  68     else:
  69       for k, v in stuff:
  70         me._setval(me._find(k, &f), v)
  71     for k, v in kw.iteritems():
  72       me._setval(me._find(k, &f), v)
  73     return me
  74
  75   ## Item access
  76   def __getitem__(me, key):
  77     cdef void *e
  78     e = me._find(key, NULL)
  79     if not e:
  80       raise KeyError, key
  81     return me._value(e)
  82   def __setitem__(me, key, value):
  83     cdef unsigned f
  84     me._setval(me._find(key, &f), value)
  85   def __delitem__(me, key):
  86     cdef void *e
  87     cdef unsigned f
  88     e = me._find(key, &f)
  89     if not e:
  90       raise KeyError, key
  91     me._del(e)
  92   def get(me, key, default = None):
  93     """D.get(KEY, [default = None]) -> VALUE: value at KEY, or DEFAULT"""
  94     cdef void *e
  95     e = me._find(key, NULL)
  96     if not e:
  97       return default
  98     return me._value(e)
  99   def setdefault(me, key, default = None):
 100     """
 101     D.setdefault(KEY, [default = None]) -> VALUE:
 102       return value at key, or store DEFAULT at key and return that"""
 103     cdef void *e
 104     cdef unsigned f
 105     e = me._find(key, &f)
 106     if f:
 107       return me._value(e)
 108     else:
 109       me._setval(e, default)
 110       return default
 111   def pop(me, key, default = None):
 112     """
 113     D.pop(KEY, [default = None]) -> VALUE:
 114       return value at key or DEFAULT, and remove KEY"""
 115     cdef void *e
 116     e = me._find(key, NULL)
 117     if not e:
 118       return default
 119     rc = me._value(e)
 120     me._del(e)
 121     return rc
 122   def popitem(me):
 123     """D.popitem() -> KEY, VALUE: return and remove an association pair"""
 124     cdef _MapIterator i
 125     cdef void *e
 126     i = me._iter()
 127     e = i._next()
 128     if not e:
 129       raise ValueError, 'popitem(): table is empty'
 130     return me._key(e), me._value(e)
 131
 132   ## Lists of items
 133   cdef object _list(me, object (*func)(Mapping m, void *e)):
 134     cdef _MapIterator i
 135     cdef void *e
 136     i = me._iter()
 137     l = []
 138     while 1:
 139       e = i._next()
 140       if not e:
 141         break
 142       l.append(func(me, e))
 143     return l
 144
 145   def keys(me):
 146     """D.keys() -> LIST: return a list of known keys"""
 147     return me._list(_map_key)
 148   def values(me):
 149     """D.values() -> LIST: return a list of known values"""
 150     return me._list(_map_value)
 151   def items(me):
 152     """D.values() -> LIST: return a list of known (KEY, VALUE) pairs"""
 153     return me._list(_map_item)
 154
 155   def clear(me):
 156     """D.clear(): remove all mappings"""
 157     cdef _MapIterator i
 158     cdef void *e
 159     i = me._iter()
 160     while 1:
 161       e = i._next()
 162       if not e:
 163         break
 164       me._del(e)
 165     return me
 166
 167   ## Iteration
 168   def __iter__(me):
 169     return MapKeyIter(me)
 170   def iterkeys(me):
 171     """D.iterkeys() -> ITER: return iterator over keys"""
 172     return MapKeyIter(me)
 173   def itervalues(me):
 174     """D.itervalues() -> ITER: return iterator over values"""
 175     return MapValueIter(me)
 176   def iteritems(me):
 177     """D.iteritems() -> ITER: return iterator over (KEY, VALUE) pairs"""
 178     return MapItemIter(me)
 179
 180 cdef class MapIterBase:
 181   cdef Mapping m
 182   cdef object (*func)(Mapping m, void *e)
 183   cdef _MapIterator i
 184   cdef int _init(me) except -1:
 185     raise TypeError, 'abstract class'
 186   def __cinit__(me):
 187     me.i = m._iter()
 188     me._init()
 189   def __iter__(me):
 190     return me
 191   def __next__(me):
 192     cdef void *e
 193     e = me.i._next()
 194     if not e:
 195       raise StopIteration
 196     return me.func(me.m, e)
 197 cdef class MapKeyIter (MapIterBase):
 198   cdef int _init(me) except -1:
 199     me.func = _map_key
 200     return 0
 201 cdef class MapValueIter (MapIterBase):
 202   cdef int _init(me) except -1:
 203     me.func = _map_value
 204     return 0
 205 cdef class MapItemIter (MapIterBase):
 206   cdef int _init(me) except -1:
 207     me.func = _map_item
 208     return 0
 209
 210 cdef object _map_key(Mapping m, void *e):
 211   return m._key(e)
 212 cdef object _map_value(Mapping m, void *e):
 213   return m._value(e)
 214 cdef object _map_item(Mapping m, void *e):
 215   return m._key(e), m._value(e)
 216
 217 ###----- That's all, folks --------------------------------------------------