From 74b297c89cffd02074521a9e1c50d12bc4948542 Mon Sep 17 00:00:00 2001
From: LordBaryhobal <lordbaryhobal@gmail.com>
Date: Fri, 5 Jun 2026 10:43:52 +0200
Subject: [PATCH] feat(checker): remove custom midas import

remove custom import statement (`midas.using`) in favor of passing type definition files as arguments to the checker
---
 .../00_syntax_prototype/02_custom_types.py    |  4 --
 .../02_simple_types.py                        |  2 -
 midas/checker/checker.py                      | 48 ++++++-------------
 3 files changed, 15 insertions(+), 39 deletions(-)

diff --git a/examples/00_syntax_prototype/02_custom_types.py b/examples/00_syntax_prototype/02_custom_types.py
index 16bf442..8678ba0 100644
--- a/examples/00_syntax_prototype/02_custom_types.py
+++ b/examples/00_syntax_prototype/02_custom_types.py
@@ -2,10 +2,6 @@
 # ruff: disable[F821]
 from __future__ import annotations
 
-# Prototype of custom type import to use valid Python syntax
-import midas
-midas.using("02_custom_types.midas")
-
 # A data-frame using a custom type
 df: Frame[
     location: GeoLocation
diff --git a/examples/01_simple_type_checking/02_simple_types.py b/examples/01_simple_type_checking/02_simple_types.py
index e964159..c015a75 100644
--- a/examples/01_simple_type_checking/02_simple_types.py
+++ b/examples/01_simple_type_checking/02_simple_types.py
@@ -1,8 +1,6 @@
 # type: ignore
 # ruff: disable [F821]
 
-midas.using("02_simple_types.midas")
-
 distance: Meter = cast(Meter, 123.45)
 time: Second = cast(Second, 6.7)
 speed = distance / time
diff --git a/midas/checker/checker.py b/midas/checker/checker.py
index dda91a5..a96b472 100644
--- a/midas/checker/checker.py
+++ b/midas/checker/checker.py
@@ -34,9 +34,15 @@ class Checker(
 ):
     """A type checker which can use custom type definitions"""
 
-    def __init__(self, locals: dict[p.Expr, int], file_path: Path):
+    def __init__(
+        self,
+        locals: dict[p.Expr, int],
+        source_path: Path,
+        types_paths: list[Path],
+    ):
         self.logger: logging.Logger = logging.getLogger("Checker")
-        self.file_path: Path = file_path
+        self.source_path: Path = source_path
+        self.types_paths: list[Path] = types_paths
         self.ctx: MidasResolver = MidasResolver()
         self.global_env: Environment = Environment()
         self.env: Environment = self.global_env
@@ -46,7 +52,7 @@ class Checker(
     def diagnostic(self, type: DiagnosticType, location: Location, message: str):
         self.diagnostics.append(
             Diagnostic(
-                file_path=self.file_path,
+                file_path=self.source_path,
                 location=location,
                 type=type,
                 message=message,
@@ -119,6 +125,12 @@ class Checker(
             list[Diagnostic]: the list of diagnostics (errors, warning, etc.)
         """
         self.diagnostics = []
+
+        for path in self.types_paths:
+            self.import_midas(path)
+        self.logger.debug(f"Midas types: {self.ctx._types}")
+        self.logger.debug(f"Midas operations: {self.ctx._operations}")
+
         for stmt in statements:
             stmt.accept(self)
 
@@ -140,30 +152,6 @@ class Checker(
             return self.env.get_at(distance, name)
         return self.global_env.get(name)
 
-    def parse_midas_import(self, expr: p.CallExpr) -> Optional[Path]:
-        """Parse a Midas import statement
-
-        The statement should be written as `midas.using("path/to/types.midas")`
-
-        Args:
-            expr (p.CallExpr): the import call expression
-
-        Returns:
-            Optional[Path]: the path to the imported file, or None if the expression is malformed
-        """
-        match expr:
-            case p.CallExpr(
-                callee=p.GetExpr(
-                    object=p.VariableExpr(name="midas"),
-                    name="using",
-                ),
-                arguments=[
-                    p.LiteralExpr(value=path),
-                ],
-            ):
-                return Path(path)
-        return None
-
     def import_midas(self, path: Path) -> None:
         """Import Midas definitions from a path
 
@@ -171,14 +159,11 @@ class Checker(
             path (Path): the import path
         """
         self.logger.debug(f"Importing type definitions from {path}")
-        path = (self.file_path.parent / path).resolve()
         lexer: MidasLexer = MidasLexer(path.read_text())
         tokens: list[Token] = lexer.process()
         parser: MidasParser = MidasParser(tokens)
         stmts: list[m.Stmt] = parser.parse()
         self.ctx.resolve(stmts)
-        self.logger.debug(f"Midas types: {self.ctx._types}")
-        self.logger.debug(f"Midas operations: {self.ctx._operations}")
 
     def visit_expression_stmt(self, stmt: p.ExpressionStmt) -> None:
         self.type_of(stmt.expr)
@@ -362,9 +347,6 @@ class Checker(
     def visit_unary_expr(self, expr: p.UnaryExpr) -> Type: ...
 
     def visit_call_expr(self, expr: p.CallExpr) -> Type:
-        if path := self.parse_midas_import(expr):
-            self.import_midas(path)
-            return UnknownType()
         callee: Type = self.type_of(expr.callee)
         if not isinstance(callee, Function):
             self.error(expr.callee.location, "Callee is not a function")