"""A more or less complete dictionary like interface for the RISC OS environment."""

import riscos

class _Environ:

    def __init__(self, initial = None):

        pass

    def __repr__(self):

        return repr(riscos.getenvdict())

    def __cmp__(self, dict):

        return cmp(riscos.getenvdict(), dict)

    def __len__(self):

        return len(riscos.getenvdict())

    def __getitem__(self, key):

        ret = riscos.getenv(key)

        if ret<>None:

            return ret

        else:

            raise KeyError

    def __setitem__(self, key, item):

        riscos.putenv(key, item)

    def __delitem__(self, key):

        riscos.delenv(key)

    def clear(self):

        # too dangerous on RISC OS

        pass

    def copy(self):

        return riscos.getenvdict()

    def keys(self): return riscos.getenvdict().keys()

    def items(self): return riscos.getenvdict().items()

    def values(self): return riscos.getenvdict().values()

    def has_key(self, key):

        value = riscos.getenv(key)

        return value<>None

    def __contains__(self, key):

        return riscos.getenv(key) is not None

    def update(self, dict):

        for k, v in dict.items():

            riscos.putenv(k, v)

    def get(self, key, failobj=None):

        value = riscos.getenv(key)

        if value<>None:

            return value

        else:

            return failobj