gremlin-python/src/main/python/gremlin_python/statics.py

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# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
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# KIND, either express or implied.  See the License for the
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#
import decimal
from types import FunctionType
from aenum import Enum


class long(int):
    pass


class bigint(int):
    pass


class short(int):
    pass


FloatType = float
ShortType = short
IntType = int
LongType = long
BigIntType = bigint
TypeType = type
ListType = list
DictType = dict
SetType = set
ByteBufferType = bytes


class timestamp(float):
    """
    In Python a timestamp is simply a float. This dummy class (similar to long), allows users to wrap a float
    in a GLV script to make sure the value is serialized as a Gremlin timestamp.
    """
    pass


class SingleByte(int):
    """
    Provides a way to pass a single byte via Gremlin.
    """
    def __new__(cls, b):
        if -128 <= b < 128:
            return int.__new__(cls, b)
        else:
            raise ValueError("value must be between -128 and 127 inclusive")


class SingleChar(str):
    """
    Provides a way to pass a single character via Gremlin.
    """
    def __new__(cls, c):
        if len(c) == 1:
            return str.__new__(cls, c)
        else:
            raise ValueError("string must contain a single character")


class GremlinType(object):
    """
    Provides a way to represent a "Java class" for Gremlin.
    """
    def __init__(self, gremlin_type):
        self.gremlin_type = gremlin_type


class BigDecimal(object):
    """
    Provides a way to represent a BigDecimal for Gremlin.
    """
    def __init__(self, scale, unscaled_value):
        self.scale = scale
        self.unscaled_value = unscaled_value

    @property
    def value(self):
        self._as_decimal = decimal.Decimal(self.unscaled_value)
        precision = len(self._as_decimal.as_tuple().digits)
        with decimal.localcontext(decimal.Context(prec=precision)):
            return self._as_decimal.scaleb(-self.scale)

    def __eq__(self, other):
        if not isinstance(other, BigDecimal):
            return False
        return self.scale == other.scale and self.unscaled_value == other.unscaled_value

    def __hash__(self):
        return hash((self.scale, self.unscaled_value))

    def __repr__(self):
        return f"BigDecimal(scale={self.scale}, unscaled_value={self.unscaled_value})"

    def __str__(self):
        return str(self.value)

"""
Create a BigDecimal from a number that can be converted to a Decimal. Note precision may be lost during the conversion.
"""
def bigdecimal(value):
    try:
        decimal_value = value if isinstance(value, decimal.Decimal) else decimal.Decimal(str(value))
        scale = -decimal_value.as_tuple().exponent
        unscaled_value = int("".join(map(str, decimal_value.as_tuple().digits)))
    except TypeError:
        raise ValueError("BigDecimal does not support NaN, Infinity or -Infinity")
    except Exception as err:
        raise ValueError(f'Encountered error: {err}. Value must be able to convert to a Decimal.')
    return BigDecimal(scale, unscaled_value if decimal_value >= 0 else -unscaled_value)


staticMethods = {}
staticEnums = {}
default_lambda_language = "gremlin-groovy"


def add_static(key, value):
    if isinstance(value, Enum):
        staticEnums[key] = value
    else:
        staticMethods[key] = value


def load_statics(global_dict):
    for key in staticMethods:
        global_dict[key] = staticMethods[key]
    for key in staticEnums:
        global_dict[key] = staticEnums[key]


def unload_statics(global_dict):
    for key in staticMethods:
        if key in global_dict:
            del global_dict[key]
    for key in staticEnums:
        if key in global_dict:
            del global_dict[key]