Files
midas/midas/checker/frames.py

155 lines
5.0 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING, Optional, TypeGuard, cast
import midas.ast.python as p
from midas.ast.location import Location
from midas.checker.frame_methods import Call, MethodRegistry
from midas.checker.reporter import FileReporter
from midas.checker.types import ColumnType, DataFrameType, TupleType, Type, UnknownType
if TYPE_CHECKING:
from midas.checker.python import PythonTyper, TypedExpr
def is_list_of_literals(exprs: list[p.Expr]) -> TypeGuard[list[p.LiteralExpr]]:
return all(isinstance(expr, p.LiteralExpr) for expr in exprs)
class FrameManager:
def __init__(self, typer: PythonTyper) -> None:
self.typer: PythonTyper = typer
self.method_resolver: MethodRegistry = MethodRegistry(self.typer)
def assign(
self,
reporter: FileReporter,
location: Location,
frame: DataFrameType,
index: p.Expr,
value_type: Type,
) -> Type:
match index:
case p.LiteralExpr(value=str() as name):
return self.assign_column(reporter, location, frame, name, value_type)
case p.ListExpr(items=indices) if is_list_of_literals(indices) and all(
isinstance(idx, str) for idx in indices
):
raise NotImplementedError
case _:
reporter.error(location, f"Invalid index type {index} on {frame}")
return UnknownType()
def assign_column(
self,
reporter: FileReporter,
location: Location,
frame: DataFrameType,
name: str,
type: Type,
) -> Type:
if not isinstance(type, ColumnType):
reporter.error(
location,
f"Cannot assign {type} to dataframe column. Must be a ColumnType",
)
return frame
return self._set_column(frame, name, type)
def get(
self,
reporter: FileReporter,
location: Location,
frame: DataFrameType,
index: p.Expr,
) -> Type:
match index:
case p.LiteralExpr(value=str() as name):
column: Optional[ColumnType] = FrameManager._get_column(frame, name)
if column is None:
reporter.error(location, f"Unknown column '{name}' on {frame}")
return UnknownType()
return column
case p.ListExpr(items=indices) if is_list_of_literals(indices) and all(
isinstance(index.value, str) for index in indices
):
names: list[str] = [cast(str, index.value) for index in indices]
columns: list[ColumnType] = []
for name in names:
column: Optional[ColumnType] = FrameManager._get_column(frame, name)
if column is None:
reporter.error(location, f"Unknown column '{name}' on {frame}")
return UnknownType()
columns.append(column)
return TupleType(items=tuple(columns))
case _:
reporter.error(location, f"Invalid index type {index} on {frame}")
return UnknownType()
@classmethod
def _set_column(
cls, frame: DataFrameType, name: str, column: ColumnType
) -> DataFrameType:
new_columns: list[DataFrameType.Column] = []
index: int = len(frame.columns)
replace: bool = False
for i, col in enumerate(frame.columns):
if col.name == name:
index = i
replace = True
# TODO: check column type here to prevent changing it
new_columns.append(col)
new_col: DataFrameType.Column = DataFrameType.Column(
index=index,
name=name,
type=column,
)
if replace:
new_columns[index] = new_col
else:
new_columns.append(new_col)
return DataFrameType(columns=new_columns)
@classmethod
def _set_columns(
cls, frame: DataFrameType, names: list[str], columns: list[ColumnType]
) -> DataFrameType:
for name, col in zip(names, columns):
frame = cls._set_column(frame, name, col)
return frame
@classmethod
def _get_column(cls, frame: DataFrameType, name: str) -> Optional[ColumnType]:
for col in frame.columns:
if col.name == name:
return col.type
return None
@classmethod
def _get_columns(
cls, frame: DataFrameType, names: list[str]
) -> list[Optional[ColumnType]]:
return [cls._get_column(frame, name) for name in names]
def call(
self,
method: str,
location: Location,
frame: DataFrameType,
positional: list[TypedExpr],
keywords: dict[str, TypedExpr],
) -> Type:
call: Call = Call(
location=location,
frame=frame,
positional=positional,
keywords=keywords,
)
return self.method_resolver.call(method, call)