From 5e87ba2cd16e07062dc1afb5853c8551391f39e3 Mon Sep 17 00:00:00 2001
From: LordBaryhobal <lordbaryhobal@gmail.com>
Date: Tue, 7 Jul 2026 10:02:52 +0200
Subject: [PATCH] fix(checker): report predicate argument errors

---
 midas/checker/evaluator.py | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/midas/checker/evaluator.py b/midas/checker/evaluator.py
index de8f9ad..baefc0d 100644
--- a/midas/checker/evaluator.py
+++ b/midas/checker/evaluator.py
@@ -2,6 +2,7 @@ from dataclasses import dataclass
 from typing import Any, Callable, Optional
 
 import midas.ast.midas as m
+from midas.ast.location import Location
 from midas.checker.preamble import Preamble
 from midas.checker.registry import TypesRegistry
 from midas.checker.reporter import FileReporter
@@ -143,7 +144,7 @@ class Evaluator(m.Expr.Visitor[Any]):
 
         match callee:
             case Predicate():
-                return self._evaluate_predicate(callee, args, kwargs)
+                return self._evaluate_predicate(expr.location, callee, args, kwargs)
             case _ if callable(callee):
                 return callee(*args, **kwargs)
             case _:
@@ -181,6 +182,7 @@ class Evaluator(m.Expr.Visitor[Any]):
 
     def _evaluate_predicate(
         self,
+        location: Location,
         predicate: Predicate,
         args: list[Any],
         kwargs: dict[str, Any],
@@ -202,7 +204,7 @@ class Evaluator(m.Expr.Visitor[Any]):
             self.scopes.append({})
         match predicate.type:
             case Function(returns=Function() as inner):
-                self._map_args(predicate.type, args, kwargs)
+                self._map_args(location, predicate.type, args, kwargs)
                 res = PartialPredicate(
                     type=inner,
                     body=predicate.body,
@@ -211,7 +213,7 @@ class Evaluator(m.Expr.Visitor[Any]):
                 )
 
             case Function():
-                self._map_args(predicate.type, args, kwargs)
+                self._map_args(location, predicate.type, args, kwargs)
                 res = self.evaluate(predicate.body)
 
             case _:
@@ -219,7 +221,13 @@ class Evaluator(m.Expr.Visitor[Any]):
         self.scopes.pop()
         return res
 
-    def _map_args(self, function: Function, args: list[Any], kwargs: dict[str, Any]):
+    def _map_args(
+        self,
+        location: Location,
+        function: Function,
+        args: list[Any],
+        kwargs: dict[str, Any],
+    ):
         """Map call arguments to a function's parameters and set their values in context
 
         Each argument is mapped to a parameter of the function, then its value
@@ -238,9 +246,20 @@ class Evaluator(m.Expr.Visitor[Any]):
         }
 
         for i, arg in enumerate(args):
+            if i >= len(positional):
+                if self.reporter is not None:
+                    self.reporter.error(
+                        location,
+                        f"Too many positional arguments, expected at most {len(positional)}, got {len(args)}",
+                    )
+                break
             param: Function.Parameter = positional[i]
             self.set_value(param.name, arg)
 
         for name, arg in kwargs.items():
+            if name not in keywords:
+                if self.reporter is not None:
+                    self.reporter.error(location, f"Unknown keyword argument '{name}'")
+                break
             param: Function.Parameter = keywords[name]
             self.set_value(param.name, arg)