Field specification possible with two-kinds of dictionaries

7 files changed, 155 insertions, 82 deletions

diff --git a/scipy/base/_internal.py b/scipy/base/_internal.py
index 6d3aa611e..626a8439f 100644
--- a/scipy/base/_internal.py
+++ b/scipy/base/_internal.py
@@ -1,6 +1,6 @@
 
 
-from multiarray import _flagdict
+from multiarray import _flagdict, dtypedescr
 
 _defflags = _flagdict.keys()
 
@@ -186,3 +186,48 @@ class flagsobj(dict):
     carray = property(get_carray, None, "")
     farray = property(get_farray, None, "")
     
+
+
+# make sure the tuple entries are PyArray_Descr
+#	   or convert them
+#
+# make sure offsets are all interpretable 
+#	   as positive integers and
+#	   convert them to positive integers if so 
+#
+#
+# return totalsize from last offset and size
+
+def _usefields(adict):
+    names = []
+    formats = []
+    offsets = []
+    titles = []
+    fnames = adict.keys()
+    for fname in fnames:
+        obj = adict[fname]
+        n = len(obj)
+        if not isinstance(obj, tuple) or n not in [2,3]:
+            raise ValueError, "entry not a 2- or 3- tuple"
+        if (n > 2) and (obj[2] == fname):
+            continue
+        num = int(obj[1])
+        if (num < 0):
+            raise ValueError, "invalid offset."
+        names.append(fname)
+        offsets.append(num)
+        formats.append(dtypedescr(obj[0]))
+        if (n > 2):
+            title = obj[2]
+        else:
+            title = None
+        titles.append(title)
+    return dtypedescr({"names" : names,
+                       "formats" : formats,
+                       "offsets" : offsets,
+                       "titles" : titles})
+    
+        
+        
+        
+        
diff --git a/scipy/base/numeric.py b/scipy/base/numeric.py
index 28e351d66..895b5ce02 100644
--- a/scipy/base/numeric.py
+++ b/scipy/base/numeric.py
@@ -1,5 +1,5 @@
 __all__ = ['newaxis', 'ndarray', 'bigndarray', 'flatiter', 'ufunc',
-           'arange', 'array', 'zeros', 'empty', 'broadcast', 'datadescr',
+           'arange', 'array', 'zeros', 'empty', 'broadcast', 'dtypedescr',
            'fromstring', 'fromfile', 'frombuffer','newbuffer','getbuffer',
            'where', 'concatenate', 'fastCopyAndTranspose',
            'register_dtype', 'set_numeric_ops', 'can_cast',
@@ -48,7 +48,7 @@ ndarray = multiarray.ndarray
 bigndarray = multiarray.bigndarray
 flatiter = multiarray.flatiter
 broadcast = multiarray.broadcast
-datadescr=multiarray.datadescr
+dtypedescr=multiarray.dtypedescr
 ufunc = type(sin)
 
 arange = multiarray.arange
diff --git a/scipy/base/src/arraymethods.c b/scipy/base/src/arraymethods.c
index d4b366709..48979599e 100644
--- a/scipy/base/src/arraymethods.c
+++ b/scipy/base/src/arraymethods.c
@@ -249,8 +249,6 @@ array_swapaxes(PyArrayObject *self, PyObject *args)
 	return PyArray_SwapAxes(self, axis1, axis2);
 }
 
-static int array_type_set(PyArrayObject *, PyObject *);
-
 static char doc_getfield[] = "m.getfield(dtype, offset) returns a field "\
 	" of the given array as a certain type.  A field is a view of "\
 	" the array's data with each itemsize determined by the given type"\
diff --git a/scipy/base/src/arrayobject.c b/scipy/base/src/arrayobject.c
index 739fd5a68..bbcd99a6b 100644
--- a/scipy/base/src/arrayobject.c
+++ b/scipy/base/src/arrayobject.c
@@ -1828,7 +1828,6 @@ array_ass_sub(PyArrayObject *self, PyObject *index, PyObject *op)
                 return -1;
         }
 	
-
 	if (PyString_Check(index) || PyUnicode_Check(index)) {
 		if (self->descr->fields) {
 			PyObject *obj;
@@ -4141,57 +4140,6 @@ array_descr_get(PyArrayObject *self)
 	return (PyObject *)self->descr;
 }
 
-static PyObject *
-array_protocol_descr_get(PyArrayObject *self)
-{
-	PyObject *res;
-	PyObject *dobj;
-
-	/* hand this off to the typeobject */
-	/* or give default */
-	if (PyArray_ISUSERDEF(self)) {
-		res = PyObject_GetAttrString((PyObject *)self->descr->typeobj, 
-					     "__array_descr__");
-		if (res) return res;
-		PyErr_Clear();
-	}
-	/* get default */
-	dobj = PyTuple_New(2);
-	if (dobj == NULL) return NULL;
-	PyTuple_SET_ITEM(dobj, 0, PyString_FromString(""));
-	PyTuple_SET_ITEM(dobj, 1, array_typestr_get(self));
-	res = PyList_New(1);
-	if (res == NULL) {Py_DECREF(dobj); return NULL;}
-	PyList_SET_ITEM(res, 0, dobj);
-	return res;
-}
-
-static PyObject *
-array_struct_get(PyArrayObject *self)
-{
-        PyArrayInterface *inter;
-        
-        inter = (PyArrayInterface *)malloc(sizeof(PyArrayInterface));
-        inter->version = 2;
-        inter->nd = self->nd;
-        inter->typekind = self->descr->kind;
-        inter->itemsize = self->descr->elsize;
-        inter->flags = self->flags;
-        /* reset unused flags */
-	inter->flags &= ~(UPDATEIFCOPY | OWNDATA);  
-        inter->strides = self->strides;
-        inter->shape = self->dimensions;
-        inter->data = self->data;
-	Py_INCREF(self);
-        return PyCObject_FromVoidPtrAndDesc(inter, self, gentype_struct_free);
-}
-
-static PyObject *
-array_type_get(PyArrayObject *self)
-{
-        Py_INCREF(self->descr->typeobj);
-        return (PyObject *)self->descr->typeobj;
-}
 
 /* If the type is changed.  
     Also needing change: strides, itemsize
@@ -4204,7 +4152,7 @@ array_type_get(PyArrayObject *self)
 */
 
 static int
-array_type_set(PyArrayObject *self, PyObject *arg)
+array_descr_set(PyArrayObject *self, PyObject *arg)
 {
         PyArray_Descr *newtype=NULL;
         intp newdim;
@@ -4263,16 +4211,25 @@ array_type_set(PyArrayObject *self, PyObject *arg)
 		self->dimensions = temp->dimensions;
 		self->nd = temp->nd;
 		self->strides = temp->strides;
-		self->descr = temp->descr;
+		Py_DECREF(newtype);
+		newtype = temp->descr;
 		/* Fool deallocator */
 		temp->nd = 0;
 		temp->dimensions = NULL;
 		temp->descr = NULL;
 		Py_DECREF(temp);
 	}
-	else {
-		self->descr = newtype;  /* steal the reference */
-	}
+		
+	if ((self->descr->elsize == newtype->elsize) && newtype->fields) {
+		PyArray_Descr *_thetype;
+		_thetype = PyArray_DescrNew(self->descr);
+		Py_XDECREF(_thetype->fields);
+		Py_INCREF(newtype->fields);
+		_thetype->fields = newtype->fields;
+		Py_DECREF(newtype);
+		newtype = _thetype;
+	}
+	self->descr = newtype; 
 	PyArray_UpdateFlags(self, UPDATE_ALL_FLAGS);
 	
         return 0;
@@ -4283,6 +4240,59 @@ array_type_set(PyArrayObject *self, PyObject *arg)
 	return -1;
 }
 
+static PyObject *
+array_protocol_descr_get(PyArrayObject *self)
+{
+	PyObject *res;
+	PyObject *dobj;
+
+	/* hand this off to the typeobject */
+	/* or give default */
+	if (PyArray_ISUSERDEF(self)) {
+		res = PyObject_GetAttrString((PyObject *)self->descr->typeobj, 
+					     "__array_descr__");
+		if (res) return res;
+		PyErr_Clear();
+	}
+	/* get default */
+	dobj = PyTuple_New(2);
+	if (dobj == NULL) return NULL;
+	PyTuple_SET_ITEM(dobj, 0, PyString_FromString(""));
+	PyTuple_SET_ITEM(dobj, 1, array_typestr_get(self));
+	res = PyList_New(1);
+	if (res == NULL) {Py_DECREF(dobj); return NULL;}
+	PyList_SET_ITEM(res, 0, dobj);
+	return res;
+}
+
+static PyObject *
+array_struct_get(PyArrayObject *self)
+{
+        PyArrayInterface *inter;
+        
+        inter = (PyArrayInterface *)malloc(sizeof(PyArrayInterface));
+        inter->version = 2;
+        inter->nd = self->nd;
+        inter->typekind = self->descr->kind;
+        inter->itemsize = self->descr->elsize;
+        inter->flags = self->flags;
+        /* reset unused flags */
+	inter->flags &= ~(UPDATEIFCOPY | OWNDATA);  
+        inter->strides = self->strides;
+        inter->shape = self->dimensions;
+        inter->data = self->data;
+	Py_INCREF(self);
+        return PyCObject_FromVoidPtrAndDesc(inter, self, gentype_struct_free);
+}
+
+static PyObject *
+array_type_get(PyArrayObject *self)
+{
+        Py_INCREF(self->descr->typeobj);
+        return (PyObject *)self->descr->typeobj;
+}
+
+
 
 static PyObject *
 array_base_get(PyArrayObject *self)
@@ -4537,7 +4547,7 @@ static PyGetSetDef array_getsetlist[] = {
 	 "base object"},
         {"dtype", 
 	 (getter)array_type_get, 
-	 (setter)array_type_set,
+	 NULL,
 	 "get array type class"},
 	{"dtypechar",
 	 (getter)array_typechar_get,
@@ -4547,10 +4557,10 @@ static PyGetSetDef array_getsetlist[] = {
 	 (getter)array_typestr_get,
 	 NULL,
 	 "get array type string"},
-	{"descr", 
+	{"dtypedescr", 
 	 (getter)array_descr_get,
-	 NULL,
-	 "get type descriptor for array"},
+	 (setter)array_descr_set,
+	 "get(set) data-type-descriptor for array"},
         {"real", 
 	 (getter)array_real_get, 
 	 (setter)array_real_set, 
diff --git a/scipy/base/src/arraytypes.inc.src b/scipy/base/src/arraytypes.inc.src
index 04ac493ac..898d391b8 100644
--- a/scipy/base/src/arraytypes.inc.src
+++ b/scipy/base/src/arraytypes.inc.src
@@ -1474,7 +1474,7 @@ static PyArray_Descr @from@_Descr = {
 	PyArray_@from@, 0,
 	_ALIGN(@align@),
 	NULL,
-	Py_NotImplemented,
+	NULL,
 	{
 		
 		(PyArray_VectorUnaryFunc*)@from@_to_BOOL, 
@@ -1533,7 +1533,7 @@ static PyArray_Descr @from@_Descr = {
 	@num@*sizeof(@fromtyp@), 
 	_ALIGN(@fromtyp@),
 	NULL,
-	Py_NotImplemented,
+	NULL,
 	{
 		
 		(PyArray_VectorUnaryFunc*)@from@_to_BOOL, 
diff --git a/scipy/base/src/multiarraymodule.c b/scipy/base/src/multiarraymodule.c
index bfa4967a6..d8fd4bedf 100644
--- a/scipy/base/src/multiarraymodule.c
+++ b/scipy/base/src/multiarraymodule.c
@@ -2775,9 +2775,25 @@ arbitrary.
 What does distinguish a title, however, is that if it is not None, 
 it will be placed at the end of the tuple inserted into the 
 fields dictionary.
+
+If the dictionary does not have "names" and "formats" entries,
+then it will be checked for conformity and used directly. 
 */
 
 static PyArray_Descr *
+_use_fields_dict(PyObject *obj)
+{
+        static PyObject *module=NULL;
+
+        if (module==NULL) {
+                module = PyImport_ImportModule("scipy.base._internal");
+                if (module == NULL) return NULL;
+        }
+        return (PyArray_Descr *)PyObject_CallMethod(module, "_usefields", 
+						    "O", obj);
+}
+
+static PyArray_Descr *
 _convert_from_dict(PyObject *obj)
 {
 	PyArray_Descr *new;
@@ -2786,23 +2802,19 @@ _convert_from_dict(PyObject *obj)
 	int n, i;
 	int totalsize;
 
-	new = PyArray_DescrNewFromType(PyArray_VOID);
-	if (new == NULL) return NULL;
 	fields = PyDict_New();
-	if (fields == NULL) goto fail;
-
+	if (fields == NULL) return (PyArray_Descr *)PyErr_NoMemory();
+	
 	names = PyDict_GetItemString(obj, "names");
 	descrs = PyDict_GetItemString(obj, "formats");
-	offsets = PyDict_GetItemString(obj, "offsets");
-	titles = PyDict_GetItemString(obj, "titles");
 
 	if (!names || !descrs) {
-		PyErr_SetString(PyExc_ValueError, 
-				"dictionary must have at least 'names', and"\
-				" 'descrs' as keys");
-		goto fail;
+		Py_DECREF(fields);
+		return _use_fields_dict(obj);
 	}
 	n = PyObject_Length(names);
+	offsets = PyDict_GetItemString(obj, "offsets");
+	titles = PyDict_GetItemString(obj, "titles");
 	if ((n > PyObject_Length(descrs)) ||			\
 	    (offsets && (n > PyObject_Length(offsets))) ||	\
 	    (titles && (n > PyObject_Length(titles)))) {
@@ -2851,12 +2863,13 @@ _convert_from_dict(PyObject *obj)
 		if ((ret == PY_FAIL) || (newdescr->elsize == 0)) goto fail;
 	}
 
+	new = PyArray_DescrNewFromType(PyArray_VOID);
+	if (new == NULL) goto fail;
 	new->elsize = totalsize;
 	new->fields = fields;
 	return new;
 
  fail:
-	Py_XDECREF(new);
 	Py_XDECREF(fields);
 	return NULL;
 }
@@ -4290,8 +4303,6 @@ setup_scalartypes(PyObject *dict)
 
 	/* Clean up string and unicode array types so they act more like
 	   strings -- get their tables from the standard types.
-	   
-	   
 	*/
 }
 
@@ -4401,7 +4412,7 @@ DL_EXPORT(void) initmultiarray(void) {
 	PyDict_SetItemString(d, "broadcast", 
 			     (PyObject *)&PyArrayMultiIter_Type);
 	Py_INCREF(&PyArrayDescr_Type);
-	PyDict_SetItemString(d, "datadescr", (PyObject *)&PyArrayDescr_Type);
+	PyDict_SetItemString(d, "dtypedescr", (PyObject *)&PyArrayDescr_Type);
 
 	/* Doesn't need to be exposed to Python 
         Py_INCREF(&PyArrayMapIter_Type);
diff --git a/scipy/base/src/scalartypes.inc.src b/scipy/base/src/scalartypes.inc.src
index c73bea9af..2fdec9b84 100644
--- a/scipy/base/src/scalartypes.inc.src
+++ b/scipy/base/src/scalartypes.inc.src
@@ -758,6 +758,11 @@ gentype_type_get(PyObject *self)
 	return (PyObject *)self->ob_type;
 }
 
+static PyObject *
+gentype_typedescr_get(PyObject *self)
+{
+	return (PyObject *)PyArray_DescrFromScalar(self);
+}
 
 static PyObject *
 gentype_base_get(PyObject *self)
@@ -890,6 +895,10 @@ static PyGetSetDef gentype_getsets[] = {
 	 (getter)gentype_typestr_get,
 	 NULL,
 	 "get array type string"},
+	{"dtypedescr",
+	 (getter)gentype_typedescr_get,
+	 NULL,
+	 "get array data-descriptor"},
         {"real", 
 	 (getter)gentype_real_get, 
 	 (setter)0,