Factorio: improve error message for config validation (#4421)

worlds/factorio/Options.py

@@ -3,13 +3,23 @@ from __future__ import annotations
 from dataclasses import dataclass
 import typing
 
-from schema import Schema, Optional, And, Or
+from schema import Schema, Optional, And, Or, SchemaError
 
 from Options import Choice, OptionDict, OptionSet, DefaultOnToggle, Range, DeathLink, Toggle, \
     StartInventoryPool, PerGameCommonOptions, OptionGroup
 
 # schema helpers
-FloatRange = lambda low, high: And(Or(int, float), lambda f: low <= f <= high)
+class FloatRange:
+    def __init__(self, low, high):
+        self._low = low
+        self._high = high
+
+    def validate(self, value):
+        if not isinstance(value, (float, int)):
+            raise SchemaError(f"should be instance of float or int, but was {value!r}")
+        if not self._low <= value <= self._high:
+            raise SchemaError(f"{value} is not between {self._low} and {self._high}")
+
 LuaBool = Or(bool, And(int, lambda n: n in (0, 1)))