Function evaluate_expression

python/examples/math/program.py:59–91

(expr: JsonValue)

        return asyncio.gather(*[evaluate_expression(e) for e in array])

    async def evaluate_expression(expr: JsonValue) -> JsonValue:
        match expr:
            case bool() | int() | float() | str() | None:
                return expr

            case { "@ref": int(index) } if not isinstance(index, bool):
                if 0 <= index < len(results):
                    return results[index]
                
                raise ValueError(f"Index {index} is out of range [0, {len(results)})")

            case { "@ref": ref_value }:
                raise ValueError(f"'ref' value must be an integer, but was ${ref_value}")

            case { "@func": str(function_name) }:
                args: list[JsonValue]
                match expr:
                    case { "@args": None }:
                        args = []
                    case { "@args": list() }:
                        args = cast(list[JsonValue], expr["@args"]) # TODO
                    case { "@args": _ }:
                        raise ValueError("Given an invalid value for '@args'.")
                    case _:
                        args = []

                return await onCall(function_name, await evaluate_array(args))
            
            case list(array_expression_elements):
                return await evaluate_array(array_expression_elements)    

            case _:
                raise ValueError("This condition should never hit")

    for step in program["@steps"]:
        results.append(await evaluate_expression(cast(JsonValue, step)))