Files
midas/midas/checker/midas.py

199 lines
6.8 KiB
Python

import logging
from pathlib import Path
from typing import Optional
import midas.ast.midas as m
from midas.checker.builtins import define_builtins
from midas.checker.registry import TypesRegistry
from midas.checker.reporter import FileReporter, Reporter
from midas.checker.types import (
AliasType,
ComplexType,
ExtensionType,
Function,
GenericType,
Type,
TypeVar,
UnknownType,
)
from midas.lexer.midas import MidasLexer
from midas.lexer.token import Token
from midas.parser.midas import MidasParser
class MidasTyper(m.Stmt.Visitor[None], m.Expr.Visitor[None], m.Type.Visitor[Type]):
"""A resolver which evaluates Midas type definitions and build a registry"""
def __init__(self, types: TypesRegistry, reporter: Reporter) -> None:
self.logger: logging.Logger = logging.getLogger("MidasTyper")
self.reporter: FileReporter = reporter.for_file(None)
self.types: TypesRegistry = types
self._local_variables: dict[str, TypeVar] = {}
self._current_name: Optional[str] = None
define_builtins(self.types)
builtins_path: Path = (Path(__file__).parent / "builtins.midas").resolve()
self.process(builtins_path.read_text(), str(builtins_path))
def process(self, source: str, path: Optional[str]):
self.reporter = self.reporter.for_file(path)
lexer: MidasLexer = MidasLexer(source)
tokens: list[Token] = lexer.process()
parser: MidasParser = MidasParser(tokens)
stmts: list[m.Stmt] = parser.parse()
for error in parser.errors:
self.reporter.error(error.token.get_location(), error.message)
self.resolve(stmts)
def get_type(self, name: str) -> Type:
"""Get a type from its name
Args:
name (str): the name of the type
Raises:
NameError: if the type is not defined
Returns:
Type: the type
"""
if name in self._local_variables:
return self._local_variables[name]
return self.types.get_type(name)
def resolve(self, stmts: list[m.Stmt]):
"""Process a sequence of statements
Args:
stmts (list[m.Stmt]): the statements
"""
for stmt in stmts:
stmt.accept(self)
def visit_type_stmt(self, stmt: m.TypeStmt) -> None:
name: str = stmt.name.lexeme
self._current_name = name
params: list[TypeVar] = self._resolve_type_params(stmt.params)
type: Type = stmt.type.accept(self)
if len(params) != 0:
type = GenericType(name=name, params=params, body=type)
else:
type = AliasType(name=name, type=type)
self.types.define_type(name, type)
self._local_variables.clear()
self._current_name = None
def visit_member_stmt(self, stmt: m.MemberStmt) -> None: ...
def visit_extend_stmt(self, stmt: m.ExtendStmt) -> None:
self._resolve_type_params(stmt.params)
base_name: str = stmt.name.lexeme
try:
_ = self.get_type(base_name)
except NameError:
self.reporter.error(stmt.name.get_location(), f"Unknown type '{base_name}'")
for member in stmt.members:
member_type: Type = member.type.accept(self)
self.types.define_member(
base_name,
member.name.lexeme,
member_type,
member.kind == m.MemberKind.METHOD,
)
def visit_predicate_stmt(self, stmt: m.PredicateStmt) -> None: ...
def visit_logical_expr(self, expr: m.LogicalExpr) -> None: ...
def visit_binary_expr(self, expr: m.BinaryExpr) -> None: ...
def visit_unary_expr(self, expr: m.UnaryExpr) -> None: ...
def visit_get_expr(self, expr: m.GetExpr) -> None: ...
def visit_variable_expr(self, expr: m.VariableExpr) -> None: ...
def visit_grouping_expr(self, expr: m.GroupingExpr) -> None:
return expr.expr.accept(self)
def visit_literal_expr(self, expr: m.LiteralExpr) -> None: ...
def visit_wildcard_expr(self, expr: m.WildcardExpr) -> None: ...
def visit_named_type(self, type: m.NamedType) -> Type:
name: str = type.name.lexeme
try:
return self.get_type(name)
except NameError:
msg: str = f"Undefined type {name}"
if self._current_name == name:
msg += ". Recursive types are not supported, use an extend block"
self.reporter.error(type.name.get_location(), msg)
return UnknownType()
def visit_generic_type(self, type: m.GenericType) -> Type:
type_: Type = type.type.accept(self)
args: list[Type] = [arg.accept(self) for arg in type.args]
try:
return self.types.apply_generic(type_, args)
except Exception as e:
self.reporter.error(type.location, f"Cannot apply generic type: {e}")
return UnknownType()
def visit_constraint_type(self, type: m.ConstraintType) -> Type:
type_: Type = type.type.accept(self)
type.constraint.accept(self)
# TODO
return UnknownType()
def visit_complex_type(self, type: m.ComplexType) -> ComplexType:
return ComplexType(
members={
member.name.lexeme: member.type.accept(self) for member in type.members
}
)
def visit_extension_type(self, type: m.ExtensionType) -> Type:
return ExtensionType(
base=type.base.accept(self),
extension=self.visit_complex_type(type.extension),
)
def visit_function_type(self, type: m.FunctionType) -> Type:
n_pos_args: int = len(type.pos_args)
n_args: int = len(type.args)
def process_arg(arg: m.FunctionType.Argument, i: int) -> Function.Argument:
return Function.Argument(
pos=i,
name=arg.name.lexeme if arg.name is not None else str(i),
type=arg.type.accept(self),
required=arg.required,
)
return Function(
pos_args=[process_arg(arg, i) for i, arg in enumerate(type.pos_args)],
args=[process_arg(arg, i + n_pos_args) for i, arg in enumerate(type.args)],
kw_args=[
process_arg(arg, i + n_pos_args + n_args)
for i, arg in enumerate(type.kw_args)
],
returns=type.returns.accept(self),
)
def _resolve_type_params(self, params: list[m.TypeParam]):
vars: list[TypeVar] = []
for param in params:
name: str = param.name.lexeme
bound: Optional[Type] = None
if param.bound is not None:
bound = param.bound.accept(self)
var = TypeVar(name=name, bound=bound)
self._local_variables[name] = var
vars.append(var)
return vars