mdw@git.distorted.org.uk Git - mLib-python/blob - atom-base.c

   1 /* -*-c-*-
   2  *
   3  * Atom 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
  27 /*----- Header files ------------------------------------------------------*/
  28
  29 #include <Python.h>
  30
  31 #include <mLib/atom.h>
  32 #include <mLib/assoc.h>
  33 #include <mLib/dstr.h>
  34
  35 #include "atom.h"
  36 #include "grim.h"
  37
  38 /*----- Data structures ---------------------------------------------------*/
  39
  40 typedef struct entry {
  41   assoc_base _b;
  42   PyObject *a;
  43 } entry;
  44
  45 /*----- Static variables --------------------------------------------------*/
  46
  47 static assoc_table obarray;
  48
  49 /*----- Main code ---------------------------------------------------------*/
  50
  51 PyObject *atom_pywrap(atom *a)
  52 {
  53   entry *e = 0;
  54   atom_pyobj *ao;
  55   unsigned f = 0;
  56
  57   e = assoc_find(&obarray, a, sizeof(entry), &f);
  58   if (!f) {
  59     ao = PyObject_NEW(atom_pyobj, &atom_pytype); ao->a = a;
  60     e->a = (PyObject *)ao;
  61   }
  62
  63   /* If we just created the new `Atom' object, we get a reference, which
  64    * belongs to the `obarray' table.  So when we return it to the caller, we
  65    * always need to increment it.
  66    */
  67   RETURN_OBJ(e->a);
  68 }
  69
  70 PyObject *atom_pyintern(PyObject *x)
  71 {
  72   atom *a;
  73   const void *p;
  74   Py_ssize_t n;
  75
  76   if (ATOM_PYCHECK(x))
  77     RETURN_OBJ(x);
  78   if (x == Py_None)
  79     a = atom_gensym(ATOM_GLOBAL);
  80   else if (!TEXT_CHECK(x))
  81     { PyErr_SetString(PyExc_TypeError, "string wanted"); return (0); }
  82   else {
  83     TEXT_PTRLEN(x, &p, &n); if (!p) return (0);
  84     a = atom_nintern(ATOM_GLOBAL, p, n);
  85   }
  86   return (atom_pywrap(a));
  87 }
  88
  89 static void atom_pydealloc(PyObject *me)
  90   { fprintf(stderr, "ouch!  freeing atom\n"); abort();  }
  91
  92 static PyObject *atom_pynew(PyTypeObject *ty, PyObject *arg, PyObject *kw)
  93 {
  94   PyObject *name = Py_None;
  95   static const char *const kwlist[] = { "name", 0 };
  96
  97   if (!PyArg_ParseTupleAndKeywords(arg, kw, "|O:new", KWLIST, &name))
  98     return (0);
  99   return (atom_pyintern(name));
 100 }
 101
 102 static PyObject *aget_name(PyObject *me, void *hunoz)
 103   { return (TEXT_FROMSTRLEN(ATOM_NAME(ATOM_A(me)), ATOM_LEN(ATOM_A(me)))); }
 104
 105 static PyObject *aget_internedp(PyObject *me, void *hunoz)
 106 {
 107   PyObject *rc = (ATOM_A(me)->f & ATOMF_GENSYM) ? Py_False : Py_True;
 108   RETURN_OBJ(rc);
 109 }
 110
 111 static PyGetSetDef atom_pygetset[] = {
 112 #define GETSETNAME(op, name) a##op##_##name
 113   GET   (name,                  "A.name -> NAME")
 114   GET   (internedp,             "A.internedp -> BOOL")
 115 #undef GETSETNAME
 116   { 0 }
 117 };
 118
 119 static PyObject *atom_pyrichcompare(PyObject *x, PyObject *y, int op)
 120 {
 121   PyObject *rc = 0;
 122
 123   switch (op) {
 124     case Py_EQ: rc = (x == y) ? Py_True : Py_False; break;
 125     case Py_NE: rc = (x != y) ? Py_True : Py_False; break;
 126     default:
 127       PyErr_SetString(PyExc_TypeError, "atoms are unordered");
 128       return (0);
 129   }
 130   RETURN_OBJ(rc);
 131 }
 132
 133 static PyObject *atom_pyrepr(PyObject *me)
 134 {
 135   PyObject *s, *sr = 0;
 136   PyObject *rc = 0;
 137   char *p;
 138   Py_ssize_t n;
 139   dstr d = DSTR_INIT;
 140
 141   if ((s = aget_name(me, 0)) == 0 ||
 142       (sr = PyObject_Repr(s)) == 0)
 143     goto done;
 144   if (!TEXT_CHECK(sr))
 145     { PyErr_SetString(PyExc_TypeError, "string wanted"); goto done; }
 146   TEXT_PTRLEN(sr, &p, &n); if (!p) goto done;
 147   dstr_puts(&d, "Atom(");
 148   dstr_putm(&d, p, n);
 149   dstr_puts(&d, ")");
 150   rc = TEXT_FROMSTRLEN(d.buf, d.len);
 151 done:
 152   Py_XDECREF(s);
 153   Py_XDECREF(sr);
 154   dstr_destroy(&d);
 155   return (rc);
 156 }
 157
 158 static Py_hash_t atom_pyhash(PyObject *me)
 159   { Py_hash_t h = ATOM_HASH(ATOM_A(me)); if (h == -1) h = -2; return (h); }
 160
 161 PyTypeObject atom_pytype = {
 162   PyVarObject_HEAD_INIT(0, 0)           /* Header */
 163   "mLib.Atom",                          /* @tp_name@ */
 164   sizeof(atom_pyobj),                   /* @tp_basicsize@ */
 165   0,                                    /* @tp_itemsize@ */
 166
 167   atom_pydealloc,                       /* @tp_dealloc@ */
 168   0,                                    /* @tp_print@ */
 169   0,                                    /* @tp_getattr@ */
 170   0,                                    /* @tp_setattr@ */
 171   0,                                    /* @tp_compare@ */
 172   atom_pyrepr,                          /* @tp_repr@ */
 173   0,                                    /* @tp_as_number@ */
 174   0,                                    /* @tp_as_sequence@ */
 175   0,                                    /* @tp_as_mapping@ */
 176   atom_pyhash,                          /* @tp_hash@ */
 177   0,                                    /* @tp_call@ */
 178   atom_pyrepr,                          /* @tp_str@ */
 179   0,                                    /* @tp_getattro@ */
 180   0,                                    /* @tp_setattro@ */
 181   0,                                    /* @tp_as_buffer@ */
 182   Py_TPFLAGS_DEFAULT,                   /* @tp_flags@ */
 183
 184   /* @tp_doc@ */
 185 "Atom.",
 186
 187   0,                                    /* @tp_traverse@ */
 188   0,                                    /* @tp_clear@ */
 189   atom_pyrichcompare,                   /* @tp_richcompare@ */
 190   0,                                    /* @tp_weaklistoffset@ */
 191   0,                                    /* @tp_iter@ */
 192   0,                                    /* @tp_iternexr@ */
 193   0,                                    /* @tp_methods@ */
 194   0,                                    /* @tp_members@ */
 195   atom_pygetset,                        /* @tp_getset@ */
 196   0,                                    /* @tp_base@ */
 197   0,                                    /* @tp_dict@ */
 198   0,                                    /* @tp_descr_get@ */
 199   0,                                    /* @tp_descr_set@ */
 200   0,                                    /* @tp_dictoffset@ */
 201   0,                                    /* @tp_init@ */
 202   PyType_GenericAlloc,                  /* @tp_alloc@ */
 203   atom_pynew,                           /* @tp_new@ */
 204   0,                                    /* @tp_free@ */
 205   0                                     /* @tp_is_gc@ */
 206 };
 207
 208 void atom_pysetup(void)
 209   { assoc_create(&obarray); PyType_Ready(&atom_pytype); }
 210
 211 /*----- That's all, folks -------------------------------------------------*/