Module: RubyPython::Conversion
- Defined in:
- lib/rubypython/conversion.rb
Overview
Acts as a namespace for methods to bidirectionally convert between native Ruby types and native Python types. Unsupported conversions raise UnsupportedConversion.
The methods in this module should be considered internal implementation to RubyPython as they all return FFI pointers to Python objects.
Defined Under Namespace
Classes: ConversionError, UnsupportedConversion
Class Method Summary collapse
-
.ptorDict(pDict) ⇒ Object
Convert an FFI::Pointer to a Python Dictionary (PyDictObject) to a Ruby Hash.
-
.ptorFloat(pNum) ⇒ Object
Convert an FFI::Pointer to a Python Float (PyFloatObject) to a Ruby Float.
-
.ptorInt(pNum) ⇒ Object
Convert an FFI::Pointer to a Python Int (PyIntObject) to a Ruby Fixnum.
-
.ptorList(pList) ⇒ Object
Convert an FFI::Pointer to a Python List (PyListObject) to a Ruby Array.
-
.ptorLong(pNum) ⇒ Object
Convert an FFI::Pointer to a Python Long (PyLongObject) to a Ruby Fixnum.
-
.ptorObject(pObj) ⇒ Object
Converts a pointer to a Python object into a native Ruby type, if possible.
-
.ptorString(pString) ⇒ Object
Convert an FFI::Pointer to a Python String (PyStringObject) to a Ruby String.
-
.ptorTuple(pTuple) ⇒ Object
Convert an FFI::Pointer to a Python Tuple (PyTupleObject) to an instance of RubyPython::Tuple, a subclass of the Ruby Array class.
-
.rtopArrayToList(rArray) ⇒ Object
Convert a Ruby Array to Python List.
-
.rtopArrayToTuple(rArray) ⇒ Object
Convert a Ruby Array (including the subclass RubyPython::Tuple) to Python tuple.
-
.rtopBigNum(rNum) ⇒ Object
Convert a Ruby Bignum to a Python Long.
-
.rtopFalse ⇒ Object
Returns a Python False value (equivalent to Ruby’s
false
). -
.rtopFixnum(rNum) ⇒ Object
Convert a Ruby Fixnum to a Python Int.
-
.rtopFloat(rNum) ⇒ Object
Convert a Ruby float to a Python Float.
-
.rtopFunction(rObj) ⇒ Object
Convert a Ruby Proc to a Python Function.
-
.rtopHash(rHash) ⇒ Object
Convert a Ruby Hash to a Python Dict.
-
.rtopNone ⇒ Object
Returns a Python None value (equivalent to Ruby’s
nil
). -
.rtopObject(rObj, is_key = false) ⇒ Object
This will attempt to convert a Ruby object to an equivalent Python native type.
-
.rtopString(rString) ⇒ Object
Convert a Ruby string to a Python string.
-
.rtopSymbol(rSymbol) ⇒ Object
Convert a Ruby Symbol to a Python String.
-
.rtopTrue ⇒ Object
Returns a Python True value (equivalent to Ruby’s
true
).
Class Method Details
.ptorDict(pDict) ⇒ Object
Convert an FFI::Pointer to a Python Dictionary (PyDictObject) to a Ruby Hash.
277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 |
# File 'lib/rubypython/conversion.rb', line 277 def self.ptorDict(pDict) rb_hash = {} pos = ::FFI::MemoryPointer.new :ssize_t pos.write_int 0 key = ::FFI::MemoryPointer.new :pointer val = ::FFI::MemoryPointer.new :pointer while RubyPython::Python.PyDict_Next(pDict, pos, key, val) != 0 #PyDict_Next sets key and val to borrowed references. We do not care #if we are able to convert them to native ruby types, but if we wind up #wrapping either in a proxy we better IncRef it to make sure it stays #around. pKey = key.read_pointer pVal = val.read_pointer rKey = ptorObject(pKey) rVal = ptorObject(pVal) RubyPython.Py_IncRef pKey if rKey.kind_of? ::FFI::Pointer RubyPython.Py_IncRef pVal if rVal.kind_of? ::FFI::Pointer rb_hash[rKey] = rVal end rb_hash end |
.ptorFloat(pNum) ⇒ Object
Convert an FFI::Pointer to a Python Float (PyFloatObject) to a Ruby Float.
260 261 262 |
# File 'lib/rubypython/conversion.rb', line 260 def self.ptorFloat(pNum) RubyPython::Python.PyFloat_AsDouble(pNum) end |
.ptorInt(pNum) ⇒ Object
Convert an FFI::Pointer to a Python Int (PyIntObject) to a Ruby Fixnum.
247 248 249 |
# File 'lib/rubypython/conversion.rb', line 247 def self.ptorInt(pNum) RubyPython::Python.PyInt_AsLong(pNum) end |
.ptorList(pList) ⇒ Object
Convert an FFI::Pointer to a Python List (PyListObject) to a Ruby Array.
233 234 235 236 237 238 239 240 241 242 243 244 |
# File 'lib/rubypython/conversion.rb', line 233 def self.ptorList(pList) rb_array = [] list_size = RubyPython::Python.PyList_Size(pList) list_size.times do |i| element = RubyPython::Python.PyList_GetItem(pList, i) rObject = ptorObject(element) rb_array.push rObject end rb_array end |
.ptorLong(pNum) ⇒ Object
Convert an FFI::Pointer to a Python Long (PyLongObject) to a Ruby Fixnum. This version does not do overflow checking, but probably should.
253 254 255 256 |
# File 'lib/rubypython/conversion.rb', line 253 def self.ptorLong(pNum) RubyPython::Python.PyLong_AsLong(pNum) # TODO Overflow Checking end |
.ptorObject(pObj) ⇒ Object
Converts a pointer to a Python object into a native Ruby type, if possible. If the conversion cannot be done, the Python object will be returned unmodified.
- pObj
-
An FFI::Pointer to a Python object.
307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 |
# File 'lib/rubypython/conversion.rb', line 307 def self.ptorObject(pObj) if RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyString_Type.to_ptr) != 0 ptorString pObj elsif RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyList_Type.to_ptr) != 0 ptorList pObj elsif RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyInt_Type.to_ptr) != 0 ptorInt pObj elsif RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyLong_Type.to_ptr) != 0 ptorLong pObj elsif RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyFloat_Type.to_ptr) != 0 ptorFloat pObj elsif RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyTuple_Type.to_ptr) != 0 ptorTuple pObj elsif RubyPython::Macros.PyObject_TypeCheck(pObj, RubyPython::Python.PyDict_Type.to_ptr) != 0 ptorDict pObj elsif pObj == RubyPython::Macros.Py_True true elsif pObj == RubyPython::Macros.Py_False false elsif pObj == RubyPython::Macros.Py_None nil else pObj end end |
.ptorString(pString) ⇒ Object
Convert an FFI::Pointer to a Python String (PyStringObject) to a Ruby String.
208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 |
# File 'lib/rubypython/conversion.rb', line 208 def self.ptorString(pString) #strPtr is a pointer to a pointer to the internal character array. #FFI will free strPtr when we are done but the internal array MUST #not be modified strPtr = ::FFI::MemoryPointer.new(:pointer) sizePtr = ::FFI::MemoryPointer.new(:ssize_t) RubyPython::Python.PyString_AsStringAndSize(pString, strPtr, sizePtr) size = case ::FFI.find_type(:ssize_t) when ::FFI.find_type(:long) sizePtr.read_long when ::FFI.find_type(:int) sizePtr.read_int when ::FFI.find_type(:long_long) sizePtr.read_long_long else nil end strPtr.read_pointer.read_string(size) end |
.ptorTuple(pTuple) ⇒ Object
Convert an FFI::Pointer to a Python Tuple (PyTupleObject) to an instance of RubyPython::Tuple, a subclass of the Ruby Array class.
266 267 268 269 270 271 272 273 |
# File 'lib/rubypython/conversion.rb', line 266 def self.ptorTuple(pTuple) #PySequence_List returns a new list. Since we are only using it as a temporary #here, we will have to DecRef it once we are done. pList = RubyPython::Python.PySequence_List pTuple rArray = ptorList pList RubyPython::Python.Py_DecRef pList RubyPython::Tuple.tuple(rArray) end |
.rtopArrayToList(rArray) ⇒ Object
Convert a Ruby Array to Python List. Returns an FFI::Pointer to a PyListObject.
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 |
# File 'lib/rubypython/conversion.rb', line 31 def self.rtopArrayToList(rArray) size = rArray.length pList = RubyPython::Python.PyList_New size if pList.null? raise ConversionError.new "Python failed to create list of size #{size}" end rArray.each_with_index do |el, i| # PyList_SetItem steals a reference, but rtopObject creates a new reference # So we wind up with giving a new reference to the Python interpreter for every # object ret = RubyPython::Python.PyList_SetItem pList, i, rtopObject(el) raise ConversionError.new "Failed to set item #{el} in array conversion" if ret == -1 end pList end |
.rtopArrayToTuple(rArray) ⇒ Object
Convert a Ruby Array (including the subclass RubyPython::Tuple) to Python tuple. Returns an FFI::Pointer to a PyTupleObject.
49 50 51 52 53 54 55 56 57 |
# File 'lib/rubypython/conversion.rb', line 49 def self.rtopArrayToTuple(rArray) pList = rtopArrayToList(rArray) pTuple = RubyPython::Python.PyList_AsTuple(pList) RubyPython::Python.Py_DecRef(pList) if pTuple.null? raise Conversion.new "Python failed to convert an intermediate list of #{rArray} to a tuple" end pTuple end |
.rtopBigNum(rNum) ⇒ Object
Convert a Ruby Bignum to a Python Long. Returns an FFI::Pointer to a PyLongObject.
94 95 96 97 98 |
# File 'lib/rubypython/conversion.rb', line 94 def self.rtopBigNum(rNum) num = RubyPython::Python.PyLong_FromLongLong(rNum) raise ConversionError.new "Failed to convert #{rNum}" if num.null? num end |
.rtopFalse ⇒ Object
Returns a Python False value (equivalent to Ruby’s false
). Returns an FFI::Pointer to Py_ZeroStruct.
110 111 112 |
# File 'lib/rubypython/conversion.rb', line 110 def self.rtopFalse RubyPython::Macros.Py_RETURN_FALSE end |
.rtopFixnum(rNum) ⇒ Object
Convert a Ruby Fixnum to a Python Int. Returns an FFI::Pointer to a PyIntObject.
86 87 88 89 90 |
# File 'lib/rubypython/conversion.rb', line 86 def self.rtopFixnum(rNum) num = RubyPython::Python.PyInt_FromLong(rNum) raise ConversionError.new "Failed to convert #{rNum}" if num.null? num end |
.rtopFloat(rNum) ⇒ Object
Convert a Ruby float to a Python Float. Returns an FFI::Pointer to a PyFloatObject.
102 103 104 105 106 |
# File 'lib/rubypython/conversion.rb', line 102 def self.rtopFloat(rNum) num = RubyPython::Python.PyFloat_FromDouble(rNum) raise ConversionError.new "Failed to convert #{rNum}" if num.null? num end |
.rtopFunction(rObj) ⇒ Object
Convert a Ruby Proc to a Python Function. Returns an FFI::Pointer to a PyCFunction.
134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 |
# File 'lib/rubypython/conversion.rb', line 134 def self.rtopFunction(rObj) proc = ::FFI::Function.new(:pointer, [:pointer, :pointer]) do |p_self, p_args| retval = rObj.call(*ptorTuple(p_args)) pObject = retval.is_a?(RubyPython::RubyPyProxy) ? retval.pObject : RubyPython::PyObject.new(retval) # make sure the refcount is >1 when pObject is destroyed pObject.xIncref pObject.pointer end defn = RubyPython::Python::PyMethodDef.new defn[:ml_name] = ::FFI::MemoryPointer.from_string("RubyPython::Proc::%s" % rObj.object_id) defn[:ml_meth] = proc defn[:ml_flags] = RubyPython::Python::METH_VARARGS defn[:ml_doc] = nil return RubyPython::Python.PyCFunction_New(defn, nil) end |
.rtopHash(rHash) ⇒ Object
Convert a Ruby Hash to a Python Dict. Returns an FFI::Pointer to a PyDictObject.
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 |
# File 'lib/rubypython/conversion.rb', line 61 def self.rtopHash(rHash) pDict = RubyPython::Python.PyDict_New if pDict.null? raise ConversionError.new "Python failed to create new dict" end rHash.each do |k,v| key = rtopObject(k, :key => true) value = rtopObject(v) # PyDict_SetItem INCREFS both the key and the value passed to it. # Since rtopObject already gives us a new reference, this is not necessary. # Thus, we decref the passed in objects to balancy things out if RubyPython::Python.PyDict_SetItem(pDict, key, value) == -1 raise ConversionError.new "Python failed to set #{key}, #{value} in dict conversion" end RubyPython::Python.Py_DecRef key RubyPython::Python.Py_DecRef value end pDict end |
.rtopNone ⇒ Object
Returns a Python None value (equivalent to Ruby’s nil
). Returns an FFI::Pointer to Py_NoneStruct.
122 123 124 |
# File 'lib/rubypython/conversion.rb', line 122 def self.rtopNone RubyPython::Macros.Py_RETURN_NONE end |
.rtopObject(rObj, is_key = false) ⇒ Object
This will attempt to convert a Ruby object to an equivalent Python native type. Returns an FFI::Pointer to a Python object (the appropriate Py_Object C structure). If the conversion is unsuccessful, will raise UnsupportedConversion.
- rObj
-
A native Ruby object.
- is_key
-
Set to
true
if the provided Ruby object will be used as a key in a Pythondict
. (This primarily matters for Array conversion.)
162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 |
# File 'lib/rubypython/conversion.rb', line 162 def self.rtopObject(rObj, is_key = false) case rObj when String rtopString rObj when RubyPython::Tuple rtopArrayToTuple rObj when Array # If this object is going to be used as a hash key we should make it a # tuple instead of a list if is_key rtopArrayToTuple rObj else rtopArrayToList rObj end when Hash rtopHash rObj when Fixnum rtopFixnum rObj when Bignum rtopBignum rObj when Float rtopFloat rObj when true rtopTrue when false rtopFalse when Symbol rtopSymbol rObj when Proc, Method rtopFunction rObj when nil rtopNone when RubyPython::PyObject rObj.xIncref rObj.pointer when RubyPython::RubyPyProxy rtopObject(rObj.pObject, is_key) when NumRu rtopObject(rObj.np_obj) else raise UnsupportedConversion.new("Unsupported type #{rObj.class} for conversion.") end end |
.rtopString(rString) ⇒ Object
Convert a Ruby string to a Python string. Returns an FFI::Pointer to a PyStringObject.
19 20 21 22 23 24 25 26 27 |
# File 'lib/rubypython/conversion.rb', line 19 def self.rtopString(rString) size = rString.respond_to?(:bytesize) ? rString.bytesize : rString.size ptr = RubyPython::Python.PyString_FromStringAndSize(rString, size) if ptr.null? raise ConversionError.new "Python failed to create a string with contents #{rString}" else ptr end end |
.rtopSymbol(rSymbol) ⇒ Object
Convert a Ruby Symbol to a Python String. Returns an FFI::Pointer to a PyStringObject.
128 129 130 |
# File 'lib/rubypython/conversion.rb', line 128 def self.rtopSymbol(rSymbol) rtopString rSymbol.to_s end |
.rtopTrue ⇒ Object
Returns a Python True value (equivalent to Ruby’s true
). Returns an FFI::Pointer to Py_TrueStruct.
116 117 118 |
# File 'lib/rubypython/conversion.rb', line 116 def self.rtopTrue RubyPython::Macros.Py_RETURN_TRUE end |