Source code for franz.openrdf.model.value

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# pylint: disable-msg=C0103 

################################################################################
# Copyright (c) 2006-2017 Franz Inc.  
# All rights reserved. This program and the accompanying materials are
# made available under the terms of the MIT License which accompanies
# this distribution, and is available at http://opensource.org/licenses/MIT
################################################################################

from __future__ import absolute_import
from __future__ import unicode_literals

from future.utils import python_2_unicode_compatible
from past.builtins import basestring
from builtins import object

from ..exceptions import IllegalArgumentException
from ..util import uris, strings


@python_2_unicode_compatible
class Value(object):
    """
    Top class in the org.openrdf.model interfaces.
    """
    
    def __str__(self):
        return self.toNTriples()

    def __repr__(self):
        return self.toNTriples()

    def get_cmp_key(self):
        """
        Return a key that will be used to compare and hash this object.
        """
        raise NotImplementedError()

    # Comparison methods rely on get_cmp_key.
    def __eq__(self, other):
        return type(self) == type(other) and self.get_cmp_key() == other.get_cmp_key()

    def __ne__(self, other):
        return not self == other

    def __hash__(self):
        return hash(self.get_cmp_key())

    def __lt__(self, other):
        if type(self) == type(other):
            return self.get_cmp_key() < other.get_cmp_key()
        else:
            return type(self) < type(other)

    def __gt__(self, other):
        if type(self) == type(other):
            return self.get_cmp_key() > other.get_cmp_key()
        else:
            return type(self) > type(other)

    def __le__(self, other):
        return not self > other

    def __ge__(self, other):
        return not self < other

    def toNTriples(self):
        """
        Return an NTriples representation of an open rdf term
        """
        raise NotImplementedError("Failed to implement 'toNTriples' on instance of type %s" % type(self).__name__)
    
    
class Resource(Value):
    pass

class URI(Resource):
    """
    Lightweight implementation of the class 'URI'.
    """
    def __init__(self, uri=None, namespace=None, localname=None):
        if uri and not isinstance(uri, basestring):
            raise IllegalArgumentException("Object of type %s passed to URI constructor where string expected: %s"
                                           % (type(uri), uri))
        if uri:
            if uri[0] == '<' and uri[len(uri) - 1] == '>':
                ## be kind and trim the uri:
                uri = uri[1:-1]
        elif namespace and localname:
            uri = namespace + localname

        self._uri = uri

    def get_cmp_key(self):
        return self.uri
    
    def getURI(self):
        """
        Return the URI (string) for 'self'.  This method is typically
        overloaded by subclasses, which may use lazy evaluation to
        retrieve the string.
        """
        return self._uri

    uri = property(getURI)
    
    def getValue(self):
        return self.getURI()

    value = property(getValue)
    
    def getLocalName(self):
        pos = uris.getLocalNameIndex(self.getURI())
        return self.uri[pos:]
    
    localname = property(getLocalName)

    def getNamespace(self):
        pos = uris.getLocalNameIndex(self.getURI())
        return self.uri[0:pos]

    namespace = property(getNamespace)

    def toNTriples(self):
        """
        Return an NTriples representation of a resource, in this case, wrap
        it in angle brackets.
        """
        return strings.encode_ntriple_uri(self.uri)


class BNode(Resource):
    """
    A blank node.
    """
    def __init__(self, id=None):
        self.id = id
        
    def getId(self):
        return self.id

    def getID(self):
        return self.id

    getValue = getID
    
    def get_cmp_key(self):
        return self.id
    
    def toNTriples(self):
        return "_:%s" % self.id


@python_2_unicode_compatible
class Namespace(object):
    """
    """
    def __init__(self, prefix, name):
        self.setPrefix(prefix)
        self.setName(name)
    
    def getName(self):
        """
        Gets the name of the current namespace (i.e. it's URI).
        """
        return self.name

    def setName(self, name): self.name = name
    
    def getPrefix(self):
        """
        Gets the prefix of the current namespace.
        """
        return self.prefix

    def setPrefix(self, prefix): self.prefix = prefix
    
    def __str__(self):
        """
        Return an odd name (that's what the RDF4J code does).
        """
        return self.prefix + " :: " + self.name