notes.txt

Questions:

    1. sequences (tuples and lists) are empty (full of NULL values)
       on creation.  On return to Python, nothing is done to check
       whether a sequence has NULL values in it.  NULL values in 
       Python will cause problems.  An alternative is to fill created
       sequences with PyNone.  This is slower, but maybe safer.  I
       believe this is what CXX does.  I need to ask others what they
       think about this.
    2. operator[] presents the biggest problems for C++ Python library
       as far as I can tell.  The problem is we need a different function
       called in the following two cases:
       
         dict_obj["a"] = 1;
         obj = dict_obj["a"];
       
       In the first case, no KeyError should be thrown.  In the 2nd,
       the KeyError should be thrown.  Unfortunately, this is not 
       possible with simple C++.  It may be possible with template
       expressions, but we aren't using those. So, for now, we will
       have to deal with KeyErrors not occurring on the RHS of equations.
       A secondary option here is to have a second argument have a 
       special function for RHS access to values.  This is likely 
       what we will do in auto generated code. 
       
       In the case that IndexErrors occur, these should always be
       thrown.
       
For release:
    1.  Change return_val to be an py::object.  This will get rid of 
        of the need to handle incref/decref on your own most of the time.
        DONE
    2.  Flesh out object to handle all types of values in a generic way:
        a. sequence access.
           DONE
        b. casting from/to standard types
            int, float, double, std::complex, char*, std::string.
           DONE
        c. attr should return a reference?  Not sure about this.
           I DONT THINK SO
    3.  Tests that always thrown exceptions aren't getting cataloged.
        This isn't a big deal in practice, but it needs to be cleaned up.
    4.  Test file conversion for ref counts
    5.  Examine all examples and make sure they make sense (and work).            
    6.  Add iter() and next() to objects.
    7.  check comparisons
        DONE.
    8.  clean up dict objects.
        DONE.
    9.  test dict object.
        DONE 
    9.  test get_item_operator for object, list, tuples, dicts.
        DONE -- but I don't really like the operator[] behavior.
        
base package
    scipy_base
    scipy_distutils
    scipy_test
    gui_thread

scipy
weave
chaco
    
weave

Note on ref counts:
There is some ref count strangness in inline() *if it is called from
a function*.  When called from the command line, the ref counts behave
correctly.  When called from a function, the first call to a
inline() causes the ref count goes up an extra count.  However,
subsequent calls don't cause any further refcount increases.  Checks
put in py::object creation and destruction look like the C++ code is
not losing a ref count.  I'm thinking that some of the stack frame
limbo played in inline() might be to blame???  Anyway, this needs
further investigation.  I'm not sure if the issue is leading to leaks
or not.

Proposed changes to weave:

* change return_val to a py::object
    This could remove almost all of the need of handling PyObject*.
* document changes.    
* review directory structure.
* outline method of aggregating functions into a single file.

EVERYTHING BELOW HERE IS DONE.
* all classes moved to py:: namespace
* made tuples mutable with indexing notation. (handy in weave)
* converted camel case names (setItem -> set_item)
* change class names to reflect boost like names and put each 
  exposed class in its own header file.
    PWOBase     -> py::object   -- object.h     
    PWOList     -> py::list     -- list.h       
    PWOTuple    -> py::tuple    -- tuple.h      
    PWOMapping  -> py::dict     -- dict.h       
    PWOCallable -> py::callable -- callable.h   
    PWOString   -> py::str      -- str.h        
    PWONumber   -> py::number   -- number.h     
    
    py::object public methods:
        int print(FILE *f, int flags) const DONE

        bool hasattr(const char* nm) const  DONE

        py::object_attr attr(const char* nm) const
        py::object_attr attr(const py::object& nm) const

        ??
        int set_attr(const char* nm, py::object& val)
        int set_attr(PyObject* nm, py::object& val)

        int del(const char* nm)
        int del(const py::object& nm)
          
        int cmp(const py::object& other) const

        bool operator == (const py::object& other) const 
        bool operator != (const py::object& other) const 
        bool operator > (const py::object& other) const 
        bool operator < (const py::object& other) const
        bool operator >= (const py::object& other) const
        bool operator <= (const py::object& other) const 
      
        PyObject* repr() const
        /*PyObject* str() const*/ // conflicts with class named str
        PyObject* type() const
        
        int hash() const
        bool is_true() const
        bool is_callable() const
        
        PyObject* disown() 


    py::sequence public methods:
        PWOSequence operator+(const PWOSequence& rhs) const
        //count
        int count(const py::object& value) const
        int count(int value) const;
        int count(double value) const;    
        int count(char* value) const;
        int count(std::string value) const;
        
        py::object operator [] (int i) const
        py::sequence get_slice(int lo, int hi) const
        
        bool in(const py::object& value) const
        bool in(int value);    
        bool in(double value);
        bool in(char* value);
        bool in(std::string value);
  
        int index(const py::object& value) const
        int index(int value) const;
        int index(double value) const;
        int index(char* value) const;
        int index(std::string value) const;    
  
        int len() const
        int length() const  // compatible with std::string

        py::sequence operator * (int count) const //repeat

    class py::tuple
        void set_item(int ndx, py::object& val)
        void set_item(int ndx, int val)
        void set_item(int ndx, double val)
        void set_item(int ndx, char* val)
        void set_item(int ndx, std::string val)
        
        // make tuples mutable like lists
        // much easier to set up call lists, etc.
        py::tuple_member operator [] (int i)
        
    class py::list

        bool del(int i)
        bool del(int lo, int hi)

        py::list_member operator [] (int i)

        void set_item(int ndx, py::object& val)
        void set_item(int ndx, int val)
        void set_item(int ndx, double val)
        void set_item(int ndx, char* val)
        void set_item(int ndx, std::string val)

        void set_slice(int lo, int hi, const py::sequence& slice)

        py::list& append(const py::object& other)
        py::list& append(int other)
        py::list& append(double other)
        py::list& append(char* other)
        py::list& append(std::string other)
  
        py::list& insert(int ndx, py::object& other)
        py::list& insert(int ndx, int other);
        py::list& insert(int ndx, double other);
        py::list& insert(int ndx, char* other);  
        py::list& insert(int ndx, std::string other);

        py::list& reverse()
        py::list& sort()

    class py::dict
        py::dict_member operator [] (const char* key)
        py::dict_member operator [] (std::string key)
  
        py::dict_member operator [] (PyObject* key)
        py::dict_member operator [] (int key)  
        py::dict_member operator [] (double key)
    
        bool has_key(PyObject* key) const
        bool has_key(const char* key) const
        // needs int, std::string, and double versions
  
        int len() const
        int length() const

        void set_item(const char* key, PyObject* val)
        void set_item(PyObject* key, PyObject* val) const
        // need int, std::string and double versions
        void clear()
        
        void del(PyObject* key)
        void del(const char* key)
        // need int, std::string, and double versions
        
        py::list items() const
        py::list keys() const