Creating buffer type

Cython/Compiler/Nodes.py

@@ -607,15 +607,29 @@ class CSimpleBaseTypeNode(CBaseTypeNode):
             return PyrexTypes.error_type
 
 class CBufferAccessTypeNode(Node):
-    #  base_type_node   CBaseTypeNode
+    #  After parsing:
     #  positional_args  [ExprNode]        List of positional arguments
     #  keyword_args     DictNode          Keyword arguments
+    #  base_type_node   CBaseTypeNode
 
-    child_attrs = ["base_type_node", "positional_args", "keyword_args"]
+    #  After PostParse:
+    #  dtype_node       CBaseTypeNode
+    #  ndim             int
 
-    def analyse(self, env):
+    #  After analysis:
+    #  type             PyrexType.PyrexType
 
-        return self.base_type_node.analyse(env)
+    child_attrs = ["base_type_node", "positional_args", "keyword_args",
+                   "dtype_node"]
+
+    dtype_node = None
+    
+    def analyse(self, env):
+        base_type = self.base_type_node.analyse(env)
+        dtype = self.dtype_node.analyse(env)
+        options = PyrexTypes.BufferOptions(dtype=dtype, ndim=self.ndim)
+        self.type = PyrexTypes.create_buffer_type(base_type, options)
+        return self.type
 
 class CComplexBaseTypeNode(CBaseTypeNode):
     # base_type   CBaseTypeNode

Cython/Compiler/ParseTreeTransforms.py

@@ -124,7 +124,7 @@ class PostParse(CythonTransform):
         # get dtype
         dtype = options.get("dtype")
         if dtype is None: raise PostParseError(node.pos, ERR_BUF_MISSING % 'dtype')
-        node.dtype = dtype
+        node.dtype_node = dtype
 
         # get ndim
         if "ndim" in provided:
@@ -143,8 +143,6 @@ class PostParse(CythonTransform):
         node.keyword_args = None
         return node
 
-
-
 class WithTransform(CythonTransform):
 
     # EXCINFO is manually set to a variable that contains

Cython/Compiler/PyrexTypes.py

@@ -4,6 +4,7 @@
 
 from Cython import Utils
 import Naming
+import copy
 
 class BaseType:
     #
@@ -183,6 +184,20 @@ class CTypedefType(BaseType):
     def __getattr__(self, name):
         return getattr(self.typedef_base_type, name)
 
+class BufferOptions:
+    # dtype         PyrexType
+    # ndim          int
+    def __init__(self, dtype, ndim):
+        self.dtype = dtype
+        self.ndim = ndim
+
+
+def create_buffer_type(base_type, buffer_options):
+    # Make a shallow copy of base_type and then annotate it
+    # with the buffer information
+    result = copy.copy(base_type)
+    result.buffer_options = buffer_options
+    return result
 
 class PyObjectType(PyrexType):
     #
@@ -193,6 +208,7 @@ class PyObjectType(PyrexType):
     default_value = "0"
     parsetuple_format = "O"
     pymemberdef_typecode = "T_OBJECT"
+    buffer_options = None # can contain a BufferOptions instance
     
     def __str__(self):
         return "Python object"

Cython/Compiler/Tests/TestBuffer.py

+from Cython.TestUtils import CythonTest
+import Cython.Compiler.Errors as Errors
+from Cython.Compiler.Nodes import *
+from Cython.Compiler.ParseTreeTransforms import *
+
+
+class TestBufferParsing(CythonTest):
+    # First, we only test the raw parser, i.e.
+    # the number and contents of arguments are NOT checked.
+    # However "dtype"/the first positional argument is special-cased
+    #  to parse a type argument rather than an expression
+
+    def parse(self, s):
+        return self.should_not_fail(lambda: self.fragment(s)).root
+
+    def not_parseable(self, expected_error, s):
+        e = self.should_fail(lambda: self.fragment(s),  Errors.CompileError)
+        self.assertEqual(expected_error, e.message_only)
+    
+    def test_basic(self):
+        t = self.parse(u"cdef object[float, 4, ndim=2, foo=foo] x")
+        bufnode = t.stats[0].base_type
+        self.assert_(isinstance(bufnode, CBufferAccessTypeNode))
+        self.assertEqual(2, len(bufnode.positional_args))
+#        print bufnode.dump()
+        # should put more here...
+        
+    def test_type_fail(self):
+        self.not_parseable("Expected: type",
+                           u"cdef object[2] x")
+    
+    def test_type_pos(self):
+        self.parse(u"cdef object[short unsigned int, 3] x")
+
+    def test_type_keyword(self):
+        self.parse(u"cdef object[foo=foo, dtype=short unsigned int] x")
+
+    def test_notype_as_expr1(self):
+        self.not_parseable("Expected: expression",
+                           u"cdef object[foo2=short unsigned int] x")
+
+    def test_notype_as_expr2(self):
+        self.not_parseable("Expected: expression",
+                           u"cdef object[int, short unsigned int] x")
+
+    def test_pos_after_key(self):
+        self.not_parseable("Non-keyword arg following keyword arg",
+                           u"cdef object[foo=1, 2] x")
+
+class TestBufferOptions(CythonTest):
+    # Tests the full parsing of the options within the brackets
+
+    def parse_opts(self, opts):
+        s = u"cdef object[%s] x" % opts
+        root = self.fragment(s, pipeline=[PostParse(self)]).root
+        buftype = root.stats[0].base_type
+        self.assert_(isinstance(buftype, CBufferAccessTypeNode))
+        self.assert_(isinstance(buftype.base_type_node, CSimpleBaseTypeNode))
+        self.assertEqual(u"object", buftype.base_type_node.name)
+        return buftype
+
+    def non_parse(self, expected_err, opts):
+        e = self.should_fail(lambda: self.parse_opts(opts))
+        self.assertEqual(expected_err, e.message_only)
+        
+    def test_basic(self):
+        buf = self.parse_opts(u"unsigned short int, 3")
+        self.assert_(isinstance(buf.dtype_node, CSimpleBaseTypeNode))
+        self.assert_(buf.dtype_node.signed == 0 and buf.dtype_node.longness == -1)
+        self.assertEqual(3, buf.ndim)
+
+    def test_dict(self):
+        buf = self.parse_opts(u"ndim=3, dtype=unsigned short int")
+        self.assert_(isinstance(buf.dtype_node, CSimpleBaseTypeNode))
+        self.assert_(buf.dtype_node.signed == 0 and buf.dtype_node.longness == -1)
+        self.assertEqual(3, buf.ndim)
+        
+    def test_dtype(self):
+        self.non_parse(ERR_BUF_MISSING % 'dtype', u"")
+    
+    def test_ndim(self):
+        self.parse_opts(u"int, 2")
+        self.non_parse(ERR_BUF_INT % 'ndim', u"int, 'a'")
+        self.non_parse(ERR_BUF_NONNEG % 'ndim', u"int, -34")
+
+    def test_use_DEF(self):
+        t = self.fragment(u"""
+        DEF ndim = 3
+        cdef object[int, ndim] x
+        cdef object[ndim=ndim, dtype=int] y
+        """, pipeline=[PostParse(self)]).root
+        self.assert_(t.stats[1].base_type.ndim == 3)
+        self.assert_(t.stats[2].base_type.ndim == 3)
+
+    # add exotic and impossible combinations as they come along