Fix the return value in MLX loader and add named constants for magic numbers

modules/mlx_loader.py

@@ -5,6 +5,10 @@ from pathlib import Path
 import modules.shared as shared
 from modules.logging_colors import logger
 
+# Constants for MLX configuration
+MLX_TOP_P_DISABLED = 0.0  # MLX expects 0.0 to disable top_p
+DEFAULT_MAX_TOKENS = 512  # Default maximum tokens for generation
+
 
 def is_apple_silicon():
     """Check if running on Apple Silicon"""
@@ -46,7 +50,7 @@ class MLXModel:
             instance.tokenizer = tokenizer
             
             logger.info(f"Successfully loaded MLX model: {model_name}")
-            return instance, instance  # Return model, tokenizer tuple for compatibility
+            return instance  # Return instance for compatibility
             
         except Exception as e:
             error_msg = str(e)
@@ -112,7 +116,7 @@ class MLXModel:
             # Create the sampler
             sampler = make_sampler(
                 temp=temperature,
-                top_p=top_p if top_p < 1.0 else 0.0,  # MLX expects 0.0 to disable
+                top_p=top_p if top_p < 1.0 else MLX_TOP_P_DISABLED,  # MLX expects 0.0 to disable
                 top_k=int(top_k) if top_k > 0 else 0,
                 min_p=min_p,
                 min_tokens_to_keep=1,  # Always keep at least one token
@@ -162,7 +166,7 @@ class MLXModel:
         if 'max_new_tokens' in state and state['max_new_tokens'] > 0:
             mlx_params['max_tokens'] = state['max_new_tokens']
         else:
-            mlx_params['max_tokens'] = 512  # Default
+            mlx_params['max_tokens'] = DEFAULT_MAX_TOKENS  # Default
         
         # Create custom sampler with advanced parameters
         sampler = self._create_mlx_sampler(state)