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# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022)
#
# Licensed 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
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import numbers
from typing import Optional, Union
class JSNumberBoundsException(Exception):
pass
class JSNumber(object):
"""Utility class for exposing JavaScript Number constants."""
# The largest int that can be represented with perfect precision
# in JavaScript.
MAX_SAFE_INTEGER = (1 << 53) - 1
# The smallest int that can be represented with perfect precision
# in JavaScript.
MIN_SAFE_INTEGER = -((1 << 53) - 1)
# The largest float that can be represented in JavaScript.
MAX_VALUE = 1.7976931348623157e308
# The closest number to zero that can be represented in JavaScript.
MIN_VALUE = 5e-324
# The largest negative float that can be represented in JavaScript.
MIN_NEGATIVE_VALUE = -MAX_VALUE
@classmethod
def validate_int_bounds(cls, value: int, value_name: Optional[str] = None) -> None:
"""Validate that an int value can be represented with perfect precision
by a JavaScript Number.
Parameters
----------
value : int
value_name : str or None
The name of the value parameter. If specified, this will be used
in any exception that is thrown.
Raises
------
JSNumberBoundsException
Raised with a human-readable explanation if the value falls outside
JavaScript int bounds.
"""
if value_name is None:
value_name = "value"
if value < cls.MIN_SAFE_INTEGER:
raise JSNumberBoundsException(
"%s (%s) must be >= -((1 << 53) - 1)" % (value_name, value)
)
elif value > cls.MAX_SAFE_INTEGER:
raise JSNumberBoundsException(
"%s (%s) must be <= (1 << 53) - 1" % (value_name, value)
)
@classmethod
def validate_float_bounds(
cls, value: Union[int, float], value_name: Optional[str]
) -> None:
"""Validate that a float value can be represented by a JavaScript Number.
Parameters
----------
value : float
value_name : str or None
The name of the value parameter. If specified, this will be used
in any exception that is thrown.
Raises
------
JSNumberBoundsException
Raised with a human-readable explanation if the value falls outside
JavaScript float bounds.
"""
if value_name is None:
value_name = "value"
if not isinstance(value, (numbers.Integral, float)):
raise JSNumberBoundsException(
"%s (%s) is not a float" % (value_name, value)
)
elif value < cls.MIN_NEGATIVE_VALUE:
raise JSNumberBoundsException(
"%s (%s) must be >= -1.797e+308" % (value_name, value)
)
elif value > cls.MAX_VALUE:
raise JSNumberBoundsException(
"%s (%s) must be <= 1.797e+308" % (value_name, value)
)
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