root/trunk/infrastructure/pyd/iteration.d

Revision 100, 4.3 kB (checked in by KirkMcDonald, 8 years ago)

* Class wrapping API replaced.
* Inheritance "shim" classes now automatically generated.
* Requires DMD 1.005 or newer. Breaks GDC support for the moment.
* Docs not yet updated to reflect changes.
* Copyright notices updated to 2007.

Line 
1 /*
2 Copyright 2006, 2007 Kirk McDonald
3
4 Permission is hereby granted, free of charge, to any person obtaining a copy of
5 this software and associated documentation files (the "Software"), to deal in
6 the Software without restriction, including without limitation the rights to
7 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
8 of the Software, and to permit persons to whom the Software is furnished to do
9 so, subject to the following conditions:
10
11 The above copyright notice and this permission notice shall be included in all
12 copies or substantial portions of the Software.
13
14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20 SOFTWARE.
21 */
22
23 /**
24  * This module provides the support for wrapping opApply with Python's
25  * iteration interface using Mikola Lysenko's StackThreads package.
26  */
27 module pyd.iteration;
28
29 import python;
30
31 import pyd.class_wrap;
32 import pyd.dg_convert;
33 import pyd.exception;
34 import pyd.make_object;
35
36 import std.traits;
37
38 import st.stackcontext;
39
40 // This exception is for yielding a PyObject* from within a StackContext.
41 class PydYield : Exception {
42     PyObject* m_py;
43     this(PyObject* py) {
44         super("");
45         m_py = py;
46     }
47     PyObject* item() { return m_py; }
48 }
49
50 // Creates an iterator object from an object.
51 PyObject* PydStackContext_FromWrapped(T, alias Iter = T.opApply, iter_t = typeof(&Iter)) (T obj) {
52     // Get the number of args the opApply's delegate argument takes
53     alias ParameterTypeTuple!(iter_t) IInfo;
54     alias ParameterTypeTuple!(IInfo[0]) Info;
55     const uint ARGS = Info.length;
56     auto sc = new StackContext(delegate void() {
57         T o = obj;
58         fn_to_dg!(iter_t) t = dg_wrapper!(T, iter_t)(o, &Iter);
59         // We yield so we can be sure to get the local variables in the
60         // enclosing function's stack frame.
61         StackContext.yield();
62
63         t(delegate int(inout Info i) {
64             StackContext.throwYield(new PydYield(PyTuple_FromItems(i)));
65             return 0;
66         });
67     });
68     // Initialize the StackContext
69     sc.run();
70     return WrapPyObject_FromObject(sc);
71 }
72
73 template wrapped_iter(T, alias Iter, iter_t = typeof(&Iter)) {
74     alias wrapped_class_object!(T) wrap_object;
75
76     // Returns an iterator object for this class
77     extern (C)
78     PyObject* iter(PyObject* _self) {
79         return exception_catcher({
80             wrap_object* self = cast(wrap_object*)_self;
81
82             return PydStackContext_FromWrapped!(T, Iter, iter_t)(self.d_obj);
83         });
84     }
85 }
86
87 // Advances an iterator object
88 extern (C)
89 PyObject* sc_iternext(PyObject* _self) {
90     return exception_catcher(delegate PyObject*() {
91         alias wrapped_class_object!(StackContext) PydSC_object;
92         PydSC_object* self = cast(PydSC_object*)_self;
93
94         try {
95             // If the StackContext is done, cease iteration.
96             if (!self.d_obj.ready()) {
97                 return null;
98             }
99             self.d_obj.run();
100         }
101         // The StackContext class yields values by throwing an exception.
102         // We catch it and pass the converted value into Python.
103         catch (PydYield y) {
104             return y.item();
105         }
106         return null;
107     });
108 }
109
110 /// Readies the iterator class if it hasn't been already.
111 void PydStackContext_Ready() {
112     alias wrapped_class_type!(StackContext) type;
113     alias wrapped_class_object!(StackContext) PydSC_object;
114    
115     if (!is_wrapped!(StackContext)) {
116         type.ob_type = PyType_Type_p;
117         type.tp_basicsize = PydSC_object.sizeof;
118         type.tp_flags     = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE;
119         type.tp_name = "PydOpApplyWrapper";
120
121         type.tp_iter = &PyObject_SelfIter;
122         type.tp_iternext = &sc_iternext;
123
124         PyType_Ready(&type);
125         is_wrapped!(StackContext) = true;
126         //wrapped_classes[typeid(StackContext)] = true;
127     }
128 }
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