gresb-cel-python 0.0.3

Evaluate expression

To use the CEL parser and evaluator, you can instantiate the Runtime class with a CEL expression, and then evaluate it with a given context.

from gresb_cel_pyhon import Runtime

# Define a CEL expression
expression = "a + b * 10"

# Create a Runtime instance with the expression
runtime = Runtime(expression)

# Define a context with variables
context = {
  "a": 5,
  "b": 3
}

# Evaluate the expression with the context
result = runtime.evaluate(context)
print(f"Result: {result}")  # Output: Result: 35

Parsing Valiation

from cel_in_py import Runtime

# Define a CEL expression
expression = "a + b * 10"

# Create a Runtime instance with the expression
runtime = Runtime(expression)

# Define a context with variables
context = {
    "a": 5,
    "b": 3
}

# Evaluate the expression with the context
result = runtime.evaluate(context)

print(f"Result: {result}")  # Output: Result: 35

Advanced Usage

The VisitorInterp class allows for extending the functionality by adding custom functions or modifying the evaluation logic.

from cel_in_py.visitor_interp import VisitorInterp

# Define a custom function
def custom_function(x):
    return x * x

# Extend the visitor with the custom function
class CustomVisitor(VisitorInterp):
    def __init__(self, context):
        super().__init__(context)
        self.function_registry["custom_function"] = custom_function

# Use the custom visitor in the runtime
expression = "custom_function(5)"
runtime = Runtime(expression)
visitor = CustomVisitor({})
result = visitor.visit(runtime.ast)

print(f"Result: {result}")  # Output: Result: 25