Module: RubyPython::Conversion

Defined in:
lib/rubypython/conversion.rb

Overview

This modules encapsulates the work of converting between native Ruby and Python types. Unsupported conversions raise UnsupportedConversion.

Defined Under Namespace

Classes: UnsupportedConversion

Class Method Summary collapse

Class Method Details

.ptorDict(pDict) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 164

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 Python.PyDict_Next(pDict, pos, key, val) != 0
    pKey = key.read_pointer
    pVal = val.read_pointer
    rKey = ptorObject(pKey)
    rVal = ptorObject(pVal)
    rb_hash[rKey] = rVal
  end

  rb_hash
end

.ptorFloat(pNum) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 153

def self.ptorFloat(pNum)
  Python.PyFloat_AsDouble(pNum)
end

.ptorInt(pNum) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 144

def self.ptorInt(pNum)
  Python.PyInt_AsLong pNum
end

.ptorList(pList) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 130

def self.ptorList(pList)
  rb_array = []
  list_size = Python.PyList_Size(pList)

  list_size.times do |i|
    element = Python.PyList_GetItem(pList, i)
    Python.Py_IncRef element
    rObject = ptorObject(element)
    rb_array.push rObject
  end

  rb_array
end

.ptorLong(pNum) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 148

def self.ptorLong(pNum)
  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. Otherwise raises an error.

Parameters:

  • pObj (FFI::Pointer) —

    a pointer to a Python object

Returns:

  • a native ruby object.

Raises:



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# File 'lib/rubypython/conversion.rb', line 189

def self.ptorObject(pObj)
  if Macros.PyObject_TypeCheck(pObj, Python.PyString_Type.to_ptr) != 0
    ptorString pObj
  elsif Macros.PyObject_TypeCheck(pObj, Python.PyList_Type.to_ptr) != 0
    ptorList pObj
  elsif Macros.PyObject_TypeCheck(pObj, Python.PyInt_Type.to_ptr) != 0
    ptorInt pObj
  elsif Macros.PyObject_TypeCheck(pObj, Python.PyLong_Type.to_ptr) != 0
    ptorLong pObj
  elsif Macros.PyObject_TypeCheck(pObj, Python.PyFloat_Type.to_ptr) != 0
    ptorFloat pObj
  elsif Macros.PyObject_TypeCheck(pObj, Python.PyTuple_Type.to_ptr) != 0
    ptorTuple pObj
  elsif Macros.PyObject_TypeCheck(pObj, Python.PyDict_Type.to_ptr) != 0
    ptorDict pObj
  elsif pObj == Macros.Py_True
    true
  elsif pObj == Macros.Py_False
    false
  elsif pObj == Macros.Py_None
    nil
  else
    pObj
  end
end

.ptorString(pString) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 126

def self.ptorString(pString)
  Python.PyString_AsString(pString)
end

.ptorTuple(pTuple) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 157

def self.ptorTuple(pTuple)
  pList = Python.PySequence_List pTuple
  rArray = ptorList pList
  Python.Py_DecRef pList
  rArray
end

.rtopArrayToList(rArray) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 16

def self.rtopArrayToList(rArray)
  size = rArray.length
  pList = Python.PyList_New size
  rArray.each_with_index do |el, i|
    Python.PyList_SetItem pList, i, rtopObject(el)
  end
  pList
end

.rtopArrayToTuple(rArray) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 25

def self.rtopArrayToTuple(rArray)
  pList = rtopArrayToList(rArray)
  pTuple = Python.PySequence_Tuple(pList)
  Python.Py_DecRef(pList)
  pTuple
end

.rtopBigNum(rNum) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 44

def self.rtopBigNum(rNum)
  Python.PyLong_FromLong(rNum)
end

.rtopFalse ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 52

def self.rtopFalse
  Macros.Py_RETURN_FALSE
end

.rtopFixnum(rNum) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 40

def self.rtopFixnum(rNum)
  Python.PyInt_FromLong(rNum)
end

.rtopFloat(rNum) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 48

def self.rtopFloat(rNum)
  Python.PyFloat_FromDouble(rNum)
end

.rtopHash(rHash) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 32

def self.rtopHash(rHash)
  pDict = Python.PyDict_New
  rHash.each do |k,v|
    Python.PyDict_SetItem pDict, rtopObject(k, key=true), rtopObject(v)
  end
  pDict
end

.rtopNone ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 60

def self.rtopNone
  Macros.Py_RETURN_NONE
end

.rtopObject(rObj, is_key = false) ⇒ FFI::Pointer

If possible converts a ruby type to an equivalent python native type.

Parameters:

  • rObj —

    a native ruby type

  • is_key (Boolean) (defaults to: false) —

    whether this object will be used as a key in a python dict.

Returns:

  • (FFI::Pointer) —

    a pointer to a C PyObject*

Raises:



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# File 'lib/rubypython/conversion.rb', line 89

def self.rtopObject(rObj, is_key=false)
  case rObj
  when String
    rtopString 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 nil
    rtopNone
  when Proc, Method
    raise UnsupportedConversion.new("Python to Ruby callbacks not suppported in legacy mode") if RubyPython.legacy_mode
    rtopProc rObj
  else
    raise UnsupportedConversion.new("Unsupported type for RTOP conversion." )
  end
end

.rtopProc(rObj) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 68

def self.rtopProc(rObj)
  pyMethodDef = Python::PyMethodDef.new
  callback = Proc.new do |py_self, py_args|
    ret = rObj.call(*RubyPyProxy.new(py_args).to_a)
    PyObject.convert(ret)[0].pointer
  end
  pyMethodDef[:ml_name] = FFI::MemoryPointer.from_string "Proc::#{rObj.object_id}"
  pyMethodDef[:ml_meth] = callback
  pyMethodDef[:ml_flags] = Python::METH_VARARGS
  pyMethodDef[:ml_doc] = nil

  Python::PyCFunction_New pyMethodDef, nil
end

.rtopString(rString) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 12

def self.rtopString(rString)
  Python.PyString_FromString(rString)
end

.rtopSymbol(rSymbol) ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 64

def self.rtopSymbol(rSymbol)
  Python.PyString_FromString rSymbol.to_s
end

.rtopTrue ⇒ Object 



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# File 'lib/rubypython/conversion.rb', line 56

def self.rtopTrue
  Macros.Py_RETURN_TRUE
end