Module arepl.aeval

An async-supporting equivalent of eval(…, 'single')

"An async-supporting equivalent of eval(..., 'single')"
from dataclasses import dataclass
from arepl.acompile import compile_to_awaitable, _InternalResult
import ast
import typing as t

class Result:
    pass

@dataclass
class ReturnResult(Result):
    "The statement returned a value."
    value: t.Any

@dataclass
class ExceptionResult(Result):
    "The statement raised an exception."
    exception: BaseException

@dataclass
class ExpressionResult(Result):
    "The statement was actually an expression, and evaluated to a value."
    value: t.Any

@dataclass
class FallthroughResult(Result):
    "The statement was an assignment, or pass, or something, and we've fallen through, with nothing to print."
    pass

async def eval_single(astob: ast.Interactive, global_vars: t.Dict[str, t.Any]) -> Result:
    "Compile and evaluate this snippet of AST, with these globals, and return its result"
    awaitable = compile_to_awaitable(astob, global_vars)
    try:
        val = await awaitable
    except _InternalResult as e:
        if e.is_expression:
            return ExpressionResult(e.value)
        else:
            return FallthroughResult()
    except BaseException as e:
        # We want to skip the innermost frame of the traceback, which shows "await awaitable".
        e.__traceback__ = e.__traceback__.tb_next # type: ignore
        return ExceptionResult(e)
    else:
        return ReturnResult(val)

Functions

async def eval_single(astob: ast.Interactive, global_vars: Dict[str, Any]) ‑> Result

Compile and evaluate this snippet of AST, with these globals, and return its result

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async def eval_single(astob: ast.Interactive, global_vars: t.Dict[str, t.Any]) -> Result:
    "Compile and evaluate this snippet of AST, with these globals, and return its result"
    awaitable = compile_to_awaitable(astob, global_vars)
    try:
        val = await awaitable
    except _InternalResult as e:
        if e.is_expression:
            return ExpressionResult(e.value)
        else:
            return FallthroughResult()
    except BaseException as e:
        # We want to skip the innermost frame of the traceback, which shows "await awaitable".
        e.__traceback__ = e.__traceback__.tb_next # type: ignore
        return ExceptionResult(e)
    else:
        return ReturnResult(val)

Classes

class Result

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class Result:
    pass

Subclasses

• ExceptionResult
• ExpressionResult
• FallthroughResult
• ReturnResult

class ReturnResult (value: Any)

The statement returned a value.

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@dataclass
class ReturnResult(Result):
    "The statement returned a value."
    value: t.Any

Ancestors

• Result

Class variables

var value : Any

class ExceptionResult (exception: BaseException)

The statement raised an exception.

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@dataclass
class ExceptionResult(Result):
    "The statement raised an exception."
    exception: BaseException

Ancestors

• Result

Class variables

var exception : BaseException

class ExpressionResult (value: Any)

The statement was actually an expression, and evaluated to a value.

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@dataclass
class ExpressionResult(Result):
    "The statement was actually an expression, and evaluated to a value."
    value: t.Any

Ancestors

• Result

Class variables

var value : Any

class FallthroughResult

The statement was an assignment, or pass, or something, and we've fallen through, with nothing to print.

Expand source code Browse git

@dataclass
class FallthroughResult(Result):
    "The statement was an assignment, or pass, or something, and we've fallen through, with nothing to print."
    pass

Ancestors

• Result