Raymond Hettinger | 9c323f8 | 2005-02-28 19:39:44 +0000 | [diff] [blame^] | 1 | |
| 2 | #include "Python.h" |
| 3 | #include "structmember.h" |
| 4 | |
| 5 | /* Functional module written and maintained |
| 6 | by Hye-Shik Chang <perky@FreeBSD.org> |
| 7 | with adaptations by Raymond Hettinger <python@rcn.com> |
| 8 | Copyright (c) 2004, 2005 Python Software Foundation. |
| 9 | All rights reserved. |
| 10 | */ |
| 11 | |
| 12 | /* partial object **********************************************************/ |
| 13 | |
| 14 | typedef struct { |
| 15 | PyObject_HEAD |
| 16 | PyObject *fn; |
| 17 | PyObject *args; |
| 18 | PyObject *kw; |
| 19 | } partialobject; |
| 20 | |
| 21 | static PyTypeObject partial_type; |
| 22 | |
| 23 | static PyObject * |
| 24 | partial_new(PyTypeObject *type, PyObject *args, PyObject *kw) |
| 25 | { |
| 26 | PyObject *func; |
| 27 | partialobject *pto; |
| 28 | |
| 29 | if (PyTuple_GET_SIZE(args) < 1) { |
| 30 | PyErr_SetString(PyExc_TypeError, |
| 31 | "type 'partial' takes at least one argument"); |
| 32 | return NULL; |
| 33 | } |
| 34 | |
| 35 | func = PyTuple_GET_ITEM(args, 0); |
| 36 | if (!PyCallable_Check(func)) { |
| 37 | PyErr_SetString(PyExc_TypeError, |
| 38 | "the first argument must be callable"); |
| 39 | return NULL; |
| 40 | } |
| 41 | |
| 42 | /* create partialobject structure */ |
| 43 | pto = (partialobject *)type->tp_alloc(type, 0); |
| 44 | if (pto == NULL) |
| 45 | return NULL; |
| 46 | |
| 47 | pto->fn = func; |
| 48 | Py_INCREF(func); |
| 49 | pto->args = PyTuple_GetSlice(args, 1, INT_MAX); |
| 50 | if (pto->args == NULL) { |
| 51 | pto->kw = NULL; |
| 52 | Py_DECREF(pto); |
| 53 | return NULL; |
| 54 | } |
| 55 | if (kw != NULL) { |
| 56 | pto->kw = PyDict_Copy(kw); |
| 57 | if (pto->kw == NULL) { |
| 58 | Py_DECREF(pto); |
| 59 | return NULL; |
| 60 | } |
| 61 | } else { |
| 62 | pto->kw = Py_None; |
| 63 | Py_INCREF(Py_None); |
| 64 | } |
| 65 | |
| 66 | return (PyObject *)pto; |
| 67 | } |
| 68 | |
| 69 | static void |
| 70 | partial_dealloc(partialobject *pto) |
| 71 | { |
| 72 | PyObject_GC_UnTrack(pto); |
| 73 | Py_XDECREF(pto->fn); |
| 74 | Py_XDECREF(pto->args); |
| 75 | Py_XDECREF(pto->kw); |
| 76 | pto->ob_type->tp_free(pto); |
| 77 | } |
| 78 | |
| 79 | static PyObject * |
| 80 | partial_call(partialobject *pto, PyObject *args, PyObject *kw) |
| 81 | { |
| 82 | PyObject *ret; |
| 83 | PyObject *argappl = NULL, *kwappl = NULL; |
| 84 | |
| 85 | assert (PyCallable_Check(pto->fn)); |
| 86 | assert (PyTuple_Check(pto->args)); |
| 87 | assert (pto->kw == Py_None || PyDict_Check(pto->kw)); |
| 88 | |
| 89 | if (PyTuple_GET_SIZE(pto->args) == 0) { |
| 90 | argappl = args; |
| 91 | Py_INCREF(args); |
| 92 | } else if (PyTuple_GET_SIZE(args) == 0) { |
| 93 | argappl = pto->args; |
| 94 | Py_INCREF(pto->args); |
| 95 | } else { |
| 96 | argappl = PySequence_Concat(pto->args, args); |
| 97 | if (argappl == NULL) |
| 98 | return NULL; |
| 99 | } |
| 100 | |
| 101 | if (pto->kw == Py_None) { |
| 102 | kwappl = kw; |
| 103 | Py_XINCREF(kw); |
| 104 | } else { |
| 105 | kwappl = PyDict_Copy(pto->kw); |
| 106 | if (kwappl == NULL) { |
| 107 | Py_DECREF(argappl); |
| 108 | return NULL; |
| 109 | } |
| 110 | if (kw != NULL) { |
| 111 | if (PyDict_Merge(kwappl, kw, 1) != 0) { |
| 112 | Py_DECREF(argappl); |
| 113 | Py_DECREF(kwappl); |
| 114 | return NULL; |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | ret = PyObject_Call(pto->fn, argappl, kwappl); |
| 120 | Py_DECREF(argappl); |
| 121 | Py_XDECREF(kwappl); |
| 122 | return ret; |
| 123 | } |
| 124 | |
| 125 | static int |
| 126 | partial_traverse(partialobject *pto, visitproc visit, void *arg) |
| 127 | { |
| 128 | Py_VISIT(pto->fn); |
| 129 | Py_VISIT(pto->args); |
| 130 | Py_VISIT(pto->kw); |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | PyDoc_STRVAR(partial_doc, |
| 135 | "partial(func, *args, **keywords) - new function with partial application\n\ |
| 136 | of the given arguments and keywords.\n"); |
| 137 | |
| 138 | #define OFF(x) offsetof(partialobject, x) |
| 139 | static PyMemberDef partial_memberlist[] = { |
| 140 | {"func", T_OBJECT, OFF(fn), READONLY, |
| 141 | "function object to use in future partial calls"}, |
| 142 | {"args", T_OBJECT, OFF(args), READONLY, |
| 143 | "tuple of arguments to future partial calls"}, |
| 144 | {"keywords", T_OBJECT, OFF(kw), READONLY, |
| 145 | "dictionary of keyword arguments to future partial calls"}, |
| 146 | {NULL} /* Sentinel */ |
| 147 | }; |
| 148 | |
| 149 | static PyTypeObject partial_type = { |
| 150 | PyObject_HEAD_INIT(NULL) |
| 151 | 0, /* ob_size */ |
| 152 | "functional.partial", /* tp_name */ |
| 153 | sizeof(partialobject), /* tp_basicsize */ |
| 154 | 0, /* tp_itemsize */ |
| 155 | /* methods */ |
| 156 | (destructor)partial_dealloc, /* tp_dealloc */ |
| 157 | 0, /* tp_print */ |
| 158 | 0, /* tp_getattr */ |
| 159 | 0, /* tp_setattr */ |
| 160 | 0, /* tp_compare */ |
| 161 | 0, /* tp_repr */ |
| 162 | 0, /* tp_as_number */ |
| 163 | 0, /* tp_as_sequence */ |
| 164 | 0, /* tp_as_mapping */ |
| 165 | 0, /* tp_hash */ |
| 166 | (ternaryfunc)partial_call, /* tp_call */ |
| 167 | 0, /* tp_str */ |
| 168 | PyObject_GenericGetAttr, /* tp_getattro */ |
| 169 | 0, /* tp_setattro */ |
| 170 | 0, /* tp_as_buffer */ |
| 171 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | |
| 172 | Py_TPFLAGS_BASETYPE, /* tp_flags */ |
| 173 | partial_doc, /* tp_doc */ |
| 174 | (traverseproc)partial_traverse, /* tp_traverse */ |
| 175 | 0, /* tp_clear */ |
| 176 | 0, /* tp_richcompare */ |
| 177 | 0, /* tp_weaklistoffset */ |
| 178 | 0, /* tp_iter */ |
| 179 | 0, /* tp_iternext */ |
| 180 | 0, /* tp_methods */ |
| 181 | partial_memberlist, /* tp_members */ |
| 182 | 0, /* tp_getset */ |
| 183 | 0, /* tp_base */ |
| 184 | 0, /* tp_dict */ |
| 185 | 0, /* tp_descr_get */ |
| 186 | 0, /* tp_descr_set */ |
| 187 | 0, /* tp_dictoffset */ |
| 188 | 0, /* tp_init */ |
| 189 | 0, /* tp_alloc */ |
| 190 | partial_new, /* tp_new */ |
| 191 | PyObject_GC_Del, /* tp_free */ |
| 192 | }; |
| 193 | |
| 194 | |
| 195 | /* module level code ********************************************************/ |
| 196 | |
| 197 | PyDoc_STRVAR(module_doc, |
| 198 | "Tools for functional programming."); |
| 199 | |
| 200 | static PyMethodDef module_methods[] = { |
| 201 | {NULL, NULL} /* sentinel */ |
| 202 | }; |
| 203 | |
| 204 | PyMODINIT_FUNC |
| 205 | initfunctional(void) |
| 206 | { |
| 207 | int i; |
| 208 | PyObject *m; |
| 209 | char *name; |
| 210 | PyTypeObject *typelist[] = { |
| 211 | &partial_type, |
| 212 | NULL |
| 213 | }; |
| 214 | |
| 215 | m = Py_InitModule3("functional", module_methods, module_doc); |
| 216 | |
| 217 | for (i=0 ; typelist[i] != NULL ; i++) { |
| 218 | if (PyType_Ready(typelist[i]) < 0) |
| 219 | return; |
| 220 | name = strchr(typelist[i]->tp_name, '.'); |
| 221 | assert (name != NULL); |
| 222 | Py_INCREF(typelist[i]); |
| 223 | PyModule_AddObject(m, name+1, (PyObject *)typelist[i]); |
| 224 | } |
| 225 | } |