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author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
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committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/celpy/__init__.py | |
parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
download | gn-ai-master.tar.gz |
Diffstat (limited to '.venv/lib/python3.12/site-packages/celpy/__init__.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/celpy/__init__.py | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/celpy/__init__.py b/.venv/lib/python3.12/site-packages/celpy/__init__.py new file mode 100644 index 00000000..0306530f --- /dev/null +++ b/.venv/lib/python3.12/site-packages/celpy/__init__.py @@ -0,0 +1,293 @@ +# SPDX-Copyright: Copyright (c) Capital One Services, LLC +# SPDX-License-Identifier: Apache-2.0 +# Copyright 2020 Capital One Services, LLC +# +# 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. + +""" +Pure Python implementation of CEL. + +.. todo:: Consolidate __init__ and parser into one module? + +Visible interface to CEL. This exposes the :py:class:`Environment`, +the :py:class:`Evaluator` run-time, and the :py:mod:`celtypes` module +with Python types wrapped to be CEL compatible. + +Example +======= + +Here's an example with some details:: + + >>> import celpy + + # A list of type names and class bindings used to create an environment. + >>> types = [] + >>> env = celpy.Environment(types) + + # Parse the code to create the CEL AST. + >>> ast = env.compile("355. / 113.") + + # Use the AST and any overriding functions to create an executable program. + >>> functions = {} + >>> prgm = env.program(ast, functions) + + # Variable bindings. + >>> activation = {} + + # Final evaluation. + >>> try: + ... result = prgm.evaluate(activation) + ... error = None + ... except CELEvalError as ex: + ... result = None + ... error = ex.args[0] + + >>> result # doctest: +ELLIPSIS + DoubleType(3.14159...) + +Another Example +=============== + +See https://github.com/google/cel-go/blob/master/examples/simple_test.go + +The model Go we're sticking close to:: + + d := cel.Declarations(decls.NewVar("name", decls.String)) + env, err := cel.NewEnv(d) + if err != nil { + log.Fatalf("environment creation error: %v\\n", err) + } + ast, iss := env.Compile(`"Hello world! I'm " + name + "."`) + // Check iss for compilation errors. + if iss.Err() != nil { + log.Fatalln(iss.Err()) + } + prg, err := env.Program(ast) + if err != nil { + log.Fatalln(err) + } + out, _, err := prg.Eval(map[string]interface{}{ + "name": "CEL", + }) + if err != nil { + log.Fatalln(err) + } + fmt.Println(out) + // Output:Hello world! I'm CEL. + +Here's the Pythonic approach, using concept patterned after the Go implementation:: + + >>> from celpy import * + >>> decls = {"name": celtypes.StringType} + >>> env = Environment(annotations=decls) + >>> ast = env.compile('"Hello world! I\\'m " + name + "."') + >>> out = env.program(ast).evaluate({"name": "CEL"}) + >>> print(out) + Hello world! I'm CEL. + +""" +import json # noqa: F401 +import logging +import sys +from typing import Any, Dict, Optional, Type, cast + +import lark + +import celpy.celtypes +from celpy.adapter import (CELJSONDecoder, CELJSONEncoder, # noqa: F401 + json_to_cel) +from celpy.celparser import CELParseError, CELParser # noqa: F401 +from celpy.evaluation import (Activation, Annotation, # noqa: F401 + CELEvalError, CELFunction, Context, Evaluator, + Result, base_functions) + +# A parsed AST. +Expression = lark.Tree + + +class Runner: + """Abstract runner. + + Given an AST, this can evaluate the AST in the context of a specific activation + with any override function definitions. + + .. todo:: add type adapter and type provider registries. + """ + def __init__( + self, + environment: 'Environment', + ast: lark.Tree, + functions: Optional[Dict[str, CELFunction]] = None + ) -> None: + self.logger = logging.getLogger(self.__class__.__name__) + self.environment = environment + self.ast = ast + self.functions = functions + + def new_activation(self, context: Context) -> Activation: + """ + Builds the working activation from the environmental defaults. + """ + return self.environment.activation().nested_activation(vars=context) + + def evaluate(self, activation: Context) -> celpy.celtypes.Value: # pragma: no cover + raise NotImplementedError + + +class InterpretedRunner(Runner): + """ + Pure AST expression evaluator. Uses :py:class:`evaluation.Evaluator` class. + + Given an AST, this evauates the AST in the context of a specific activation. + + The returned value will be a celtypes type. + + Generally, this should raise an :exc:`CELEvalError` for most kinds of ordinary problems. + It may raise an :exc:`CELUnsupportedError` for future features. + + .. todo:: Refractor the Evaluator constructor from evaluation. + """ + def evaluate(self, context: Context) -> celpy.celtypes.Value: + e = Evaluator( + ast=self.ast, + activation=self.new_activation(context), + functions=self.functions + ) + value = e.evaluate() + return value + + +class CompiledRunner(Runner): + """ + Python compiled expression evaluator. Uses Python byte code and :py:func:`eval`. + + Given an AST, this evauates the AST in the context of a specific activation. + + Transform the AST into Python, uses :py:func:`compile` to create a code object. + Uses :py:func:`eval` to evaluate. + """ + def __init__( + self, + environment: 'Environment', + ast: lark.Tree, + functions: Optional[Dict[str, CELFunction]] = None + ) -> None: + super().__init__(environment, ast, functions) + # Transform AST to Python. + # compile() + # cache executable code object. + + def evaluate(self, activation: Context) -> celpy.celtypes.Value: + # eval() code object with activation as locals, and built-ins as gobals. + return super().evaluate(activation) + + +# TODO: Refactor classes into a separate "cel_protobuf" module. +# TODO: Becomes cel_protobuf.Int32Value +class Int32Value(celpy.celtypes.IntType): + def __new__( + cls: Type['Int32Value'], + value: Any = 0, + ) -> 'Int32Value': + """TODO: Check range. This seems to matter for protobuf.""" + if isinstance(value, celpy.celtypes.IntType): + return cast(Int32Value, super().__new__(cls, value)) + # TODO: elif other type conversions... + else: + convert = celpy.celtypes.int64(int) + return cast(Int32Value, super().__new__(cls, convert(value))) + + +# The "well-known" types in a google.protobuf package. +# We map these to CEl types instead of defining additional Protobuf Types. +# This approach bypasses some of the range constraints that are part of these types. +# It may also cause values to compare as equal when they were originally distinct types. +googleapis = { + 'google.protobuf.Int32Value': celpy.celtypes.IntType, + 'google.protobuf.UInt32Value': celpy.celtypes.UintType, + 'google.protobuf.Int64Value': celpy.celtypes.IntType, + 'google.protobuf.UInt64Value': celpy.celtypes.UintType, + 'google.protobuf.FloatValue': celpy.celtypes.DoubleType, + 'google.protobuf.DoubleValue': celpy.celtypes.DoubleType, + 'google.protobuf.BoolValue': celpy.celtypes.BoolType, + 'google.protobuf.BytesValue': celpy.celtypes.BytesType, + 'google.protobuf.StringValue': celpy.celtypes.StringType, + 'google.protobuf.ListValue': celpy.celtypes.ListType, + 'google.protobuf.Struct': celpy.celtypes.MessageType, +} + + +class Environment: + """Compiles CEL text to create an Expression object. + + From the Go implementation, there are things to work with the type annotations: + + - type adapters registry make other native types available for CEL. + + - type providers registry make ProtoBuf types available for CEL. + + .. todo:: Add adapter and provider registries to the Environment. + """ + def __init__( + self, + package: Optional[str] = None, + annotations: Optional[Dict[str, Annotation]] = None, + runner_class: Optional[Type[Runner]] = None + ) -> None: + """ + Create a new environment. + + This also increases the default recursion limit to handle the defined minimums for CEL. + + :param package: An optional package name used to resolve names in an Activation + :param annotations: Names with type annotations. + There are two flavors of names provided here. + + - Variable names based on :py:mod:``celtypes`` + + - Function names, using ``typing.Callable``. + :param runner_class: the class of Runner to use, either InterpretedRunner or CompiledRunner + """ + sys.setrecursionlimit(2500) + self.logger = logging.getLogger(self.__class__.__name__) + self.package: Optional[str] = package + self.annotations: Dict[str, Annotation] = annotations or {} + self.logger.info("Type Annotations %r", self.annotations) + self.runner_class: Type[Runner] = runner_class or InterpretedRunner + self.cel_parser = CELParser() + self.runnable: Runner + + # Fold in standard annotations. These (generally) define well-known protobuf types. + self.annotations.update(googleapis) + # We'd like to add 'type.googleapis.com/google' directly, but it seems to be an alias + # for 'google', the path after the '/' in the uri. + + def compile(self, text: str) -> Expression: + """Compile the CEL source. This can raise syntax error exceptions.""" + ast = self.cel_parser.parse(text) + return ast + + def program( + self, + expr: lark.Tree, + functions: Optional[Dict[str, CELFunction]] = None + ) -> Runner: + """Transforms the AST into an executable runner.""" + self.logger.info("Package %r", self.package) + runner_class = self.runner_class + self.runnable = runner_class(self, expr, functions) + return self.runnable + + def activation(self) -> Activation: + """Returns a base activation""" + activation = Activation(package=self.package, annotations=self.annotations) + return activation |