avoid Where() enumerators when possible

src/SMAPI.Installer/InteractiveInstaller.cs

@@ -377,8 +377,11 @@ internal class InteractiveInstaller
             {
                 // copy SMAPI files to game dir
                 this.PrintDebug("Adding SMAPI files...");
-                foreach (FileSystemInfo sourceEntry in paths.BundleDir.EnumerateFileSystemInfos().Where(this.ShouldCopy))
+                foreach (FileSystemInfo sourceEntry in paths.BundleDir.EnumerateFileSystemInfos())
                 {
+                    if (!this.ShouldCopy(sourceEntry))
+                        continue;
+
                     this.InteractivelyDelete(Path.Combine(paths.GameDir.FullName, sourceEntry.Name), allowUserInput);
                     this.RecursiveCopy(sourceEntry, paths.GameDir);
                 }

src/SMAPI.Toolkit/Framework/ModScanning/ModScanner.cs

@@ -329,8 +329,11 @@ public class ModScanner
     {
         bool hasXnbFile = false;
 
-        foreach (FileInfo file in files.Where(this.IsRelevant))
+        foreach (FileInfo file in files)
         {
+            if (!this.IsRelevant(file))
+                continue;
+
             if (this.StrictXnbModExtensions.Contains(file.Extension))
             {
                 hasXnbFile = true;

src/SMAPI.Web/Framework/Caching/Mods/ModCacheMemoryRepository.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using StardewModdingAPI.Toolkit.Framework.UpdateData;
 
 namespace StardewModdingAPI.Web.Framework.Caching.Mods;
@@ -13,7 +12,7 @@ internal class ModCacheMemoryRepository : BaseCacheRepository, IModCacheReposito
     ** Fields
     *********/
     /// <summary>The cached mod data indexed by <c>{site key}:{ID}</c>.</summary>
-    private readonly IDictionary<string, Cached<IModPage>> Mods = new Dictionary<string, Cached<IModPage>>(StringComparer.OrdinalIgnoreCase);
+    private readonly Dictionary<string, Cached<IModPage>> Mods = new(StringComparer.OrdinalIgnoreCase);
 
 
     /*********
@@ -57,13 +56,11 @@ internal class ModCacheMemoryRepository : BaseCacheRepository, IModCacheReposito
     {
         DateTimeOffset minDate = DateTimeOffset.UtcNow.Subtract(age);
 
-        string[] staleKeys = this.Mods
-            .Where(p => p.Value.LastRequested < minDate)
-            .Select(p => p.Key)
-            .ToArray();
-
-        foreach (string key in staleKeys)
-            this.Mods.Remove(key);
+        foreach ((string key, var modPage) in this.Mods)
+        {
+            if (modPage.LastRequested < minDate)
+                this.Mods.Remove(key);
+        }
     }
 
 

src/SMAPI/Framework/ContentCoordinator.cs

@@ -499,8 +499,11 @@ internal class ContentCoordinator : IDisposable
         return this.ContentManagerLock.InReadLock(() =>
         {
             List<object> values = [];
-            foreach (IContentManager content in this.ContentManagers.Where(p => !p.IsNamespaced && p.IsLoaded(assetName)))
+            foreach (IContentManager content in this.ContentManagers)
             {
+                if (content.IsNamespaced || !content.IsLoaded(assetName))
+                    continue;
+
                 object value = content.LoadExact<object>(assetName, useCache: true);
                 values.Add(value);
             }

src/SMAPI/Framework/Logging/LogManager.cs

@@ -281,7 +281,7 @@ internal class LogManager : IDisposable
     /// <param name="logParanoidWarnings">Whether to log issues for mods which directly use potentially sensitive .NET APIs like file or shell access.</param>
     /// <param name="logTechnicalDetailsForBrokenMods">Whether to include more technical details about broken mods in the TRACE logs. This is mainly useful for creating compatibility rewriters.</param>
     /// <param name="hasHarmonyFix">Whether Harmony was fixed to work with Stardew Valley.</param>
-    public void LogModInfo(IModMetadata[] loaded, IModMetadata[] loadedContentPacks, IModMetadata[] loadedMods, IReadOnlyList<IModMetadata> skippedMods, bool logParanoidWarnings, bool logTechnicalDetailsForBrokenMods, bool hasHarmonyFix)
+    public void LogModInfo(IReadOnlyList<IModMetadata> loaded, IReadOnlyList<IModMetadata> loadedContentPacks, IReadOnlyList<IModMetadata> loadedMods, IReadOnlyList<IModMetadata> skippedMods, bool logParanoidWarnings, bool logTechnicalDetailsForBrokenMods, bool hasHarmonyFix)
     {
         // report malicious mod
         foreach (IModMetadata mod in skippedMods)
@@ -300,7 +300,7 @@ internal class LogManager : IDisposable
         }
 
         // log loaded mods
-        this.Monitor.Log($"Loaded {loadedMods.Length} mods" + (loadedMods.Length > 0 ? ":" : "."), LogLevel.Info);
+        this.Monitor.Log($"Loaded {loadedMods.Count} mods" + (loadedMods.Count > 0 ? ":" : "."), LogLevel.Info);
         foreach (IModMetadata metadata in loadedMods.OrderBy(p => p.DisplayName))
         {
             IManifest manifest = metadata.Manifest;
@@ -319,7 +319,7 @@ internal class LogManager : IDisposable
         {
             string? GetModDisplayName(string id) => loadedMods.FirstOrDefault(p => p.HasId(id))?.DisplayName;
 
-            this.Monitor.Log($"Loaded {loadedContentPacks.Length} content packs:", LogLevel.Info);
+            this.Monitor.Log($"Loaded {loadedContentPacks.Count} content packs:", LogLevel.Info);
             foreach (IModMetadata metadata in loadedContentPacks.OrderBy(p => p.DisplayName))
             {
                 IManifest manifest = metadata.Manifest;

src/SMAPI/Framework/ModLoading/Framework/RecursiveRewriter.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Mono.Cecil;
@@ -69,16 +68,19 @@ internal class RecursiveRewriter
     /// <returns>Returns whether the module was modified.</returns>
     public bool RewriteModule()
     {
-        IEnumerable<TypeDefinition> types = this.Module.GetTypes().Where(type => type.BaseType != null); // skip special types like <Module>
-
         bool changed = false;
 
         try
         {
             changed |= this.RewriteModuleImpl(this.Module);
 
-            foreach (TypeDefinition type in types)
+            foreach (TypeDefinition type in this.Module.GetTypes())
+            {
+                if (type.BaseType is null)
+                    continue; // skip special types like <Module>
+
                 changed |= this.RewriteTypeDefinition(type);
+            }
         }
         catch (Exception ex)
         {
@@ -293,8 +295,7 @@ internal class RecursiveRewriter
                 MethodDefinition? constructor = (newAttrType ?? attribute.AttributeType)
                     .Resolve()
                     ?.Methods
-                    .Where(method => method.IsConstructor)
-                    .FirstOrDefault(ctor => RewriteHelper.HasMatchingSignature(ctor, attribute.Constructor));
+                    .FirstOrDefault(method => method.IsConstructor && RewriteHelper.HasMatchingSignature(method, attribute.Constructor));
                 if (constructor == null)
                     throw new InvalidOperationException($"Can't rewrite attribute type '{attribute.AttributeType.FullName}' to '{newAttrType?.FullName}', no equivalent constructor found.");
 

src/SMAPI/Framework/ModLoading/ModResolver.cs

@@ -225,10 +225,13 @@ internal class ModResolver
         var states = mods.ToDictionary(mod => mod, _ => ModDependencyStatus.Queued);
 
         // handle failed mods
-        foreach (IModMetadata mod in mods.Where(m => m.Status == ModMetadataStatus.Failed))
+        foreach (IModMetadata mod in mods)
         {
-            states[mod] = ModDependencyStatus.Failed;
-            sortedMods.Push(mod);
+            if (mod.Status is ModMetadataStatus.Failed)
+            {
+                states[mod] = ModDependencyStatus.Failed;
+                sortedMods.Push(mod);
+            }
         }
 
         // sort mods

src/SMAPI/Framework/ModLoading/Rewriters/HeuristicMethodRewriter.cs

@@ -47,8 +47,11 @@ internal class HeuristicMethodRewriter : BaseInstructionHandler
 
         // get method definition
         MethodDefinition? method = null;
-        foreach (MethodDefinition match in type.Methods.Where(p => p.Name == methodRef.Name))
+        foreach (MethodDefinition match in type.Methods)
         {
+            if (match.Name != methodRef.Name)
+                continue;
+
             // reference matches initial parameters of definition
             if (methodRef.Parameters.Count >= match.Parameters.Count || !this.InitialParametersMatch(methodRef, match))
                 continue;

src/SMAPI/Framework/SCore.cs

@@ -484,10 +484,13 @@ internal class SCore : IDisposable
             {
                 bool anyIgnored = false;
 
-                foreach (IModMetadata mod in mods.Where(p => p.IsIgnored))
+                foreach (IModMetadata mod in mods)
                 {
-                    anyIgnored = true;
-                    this.Monitor.Log($"  Skipped {mod.GetRelativePathWithRoot()} (folder name starts with a dot).");
+                    if (mod.IsIgnored)
+                    {
+                        anyIgnored = true;
+                        this.Monitor.Log($"  Skipped {mod.GetRelativePathWithRoot()} (folder name starts with a dot).");
+                    }
                 }
 
                 if (anyIgnored)
@@ -1982,9 +1985,18 @@ internal class SCore : IDisposable
             }
         }
 
-        IModMetadata[] loaded = this.ModRegistry.GetAll().ToArray();
-        IModMetadata[] loadedContentPacks = loaded.Where(p => p.IsContentPack).ToArray();
-        IModMetadata[] loadedMods = loaded.Where(p => !p.IsContentPack).ToArray();
+        List<IModMetadata> loaded = [];
+        List<IModMetadata> loadedContentPacks = [];
+        List<IModMetadata> loadedMods = [];
+        foreach (IModMetadata mod in this.ModRegistry.GetAll())
+        {
+            loaded.Add(mod);
+
+            if (mod.IsContentPack)
+                loadedContentPacks.Add(mod);
+            else
+                loadedMods.Add(mod);
+        }
 
         // unlock content packs
         this.ModRegistry.AreAllModsLoaded = true;
@@ -2103,10 +2115,10 @@ internal class SCore : IDisposable
 
         // validate dependencies
         // Although dependencies are validated before mods are loaded, a dependency may have failed to load.
-        foreach (IManifestDependency dependency in manifest!.Dependencies.Where(p => p.IsRequired))
+        foreach (IManifestDependency dependency in manifest!.Dependencies)
         {
             // not missing
-            if (this.ModRegistry.Get(dependency.UniqueID) != null)
+            if (!dependency.IsRequired || this.ModRegistry.Get(dependency.UniqueID) != null)
                 continue;
 
             // ignored in compatibility list (e.g. fully replaced by the game code)
@@ -2319,23 +2331,34 @@ internal class SCore : IDisposable
         mod = null;
 
         // find type
-        TypeInfo[] modEntries = modAssembly.DefinedTypes.Where(type => typeof(Mod).IsAssignableFrom(type) && !type.IsAbstract).Take(2).ToArray();
-        if (modEntries.Length == 0)
+        TypeInfo? modType = null;
+        foreach (TypeInfo type in modAssembly.DefinedTypes)
+        {
+            // skip: not a Mod type
+            if (!typeof(Mod).IsAssignableFrom(type) || type.IsAbstract)
+                continue;
+
+            // fail: multiple Mod types found
+            if (modType is not null)
+            {
+                error = $"its DLL contains multiple '{nameof(Mod)}' subclasses.";
+                return false;
+            }
+
+            // else save mod type
+            modType = type;
+        }
+        if (modType is null)
         {
             error = $"its DLL has no '{nameof(Mod)}' subclass.";
             return false;
         }
-        if (modEntries.Length > 1)
-        {
-            error = $"its DLL contains multiple '{nameof(Mod)}' subclasses.";
-            return false;
-        }
 
         // get implementation
         Context.HeuristicModsRunningCode.Push(metadata);
         try
         {
-            mod = (Mod?)modAssembly.CreateInstance(modEntries[0].ToString());
+            mod = (Mod?)modAssembly.CreateInstance(modType.ToString());
         }
         finally
         {

src/SMAPI/Framework/SMultiplayer.cs

@@ -192,8 +192,11 @@ internal class SMultiplayer : Multiplayer
                     newPeer.SendMessage(new OutgoingMessage((byte)MessageType.ModContext, Game1.player.UniqueMultiplayerID, this.GetContextSyncMessageFields()));
 
                     // reply with other players' context
-                    foreach (MultiplayerPeer otherPeer in this.Peers.Values.Where(p => p.PlayerID != newPeer.PlayerID))
+                    foreach (MultiplayerPeer otherPeer in this.Peers.Values)
                     {
+                        if (otherPeer.PlayerID == newPeer.PlayerID)
+                            continue;
+
                         this.Monitor.VerboseLog($"   Replying with context for player {otherPeer.PlayerID}...");
                         newPeer.SendMessage(new OutgoingMessage((byte)MessageType.ModContext, otherPeer.PlayerID, this.GetContextSyncMessageFields(otherPeer)));
                     }
@@ -202,8 +205,11 @@ internal class SMultiplayer : Multiplayer
                     if (this.Peers.Count > 1)
                     {
                         object[] fields = this.GetContextSyncMessageFields(newPeer);
-                        foreach (MultiplayerPeer otherPeer in this.Peers.Values.Where(p => p.PlayerID != newPeer.PlayerID))
+                        foreach (MultiplayerPeer otherPeer in this.Peers.Values)
                         {
+                            if (otherPeer.PlayerID == newPeer.PlayerID)
+                                continue;
+
                             this.Monitor.VerboseLog($"   Forwarding context to player {otherPeer.PlayerID}...");
                             otherPeer.SendMessage(new OutgoingMessage((byte)MessageType.ModContext, newPeer.PlayerID, fields));
                         }

src/SMAPI/Framework/StateTracking/ChestTracker.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using StardewModdingAPI.Framework.StateTracking.Comparers;
 using StardewModdingAPI.Framework.StateTracking.FieldWatchers;
 using StardewValley;
@@ -16,7 +15,7 @@ internal class ChestTracker : IDisposable
     ** Fields
     *********/
     /// <summary>The item stack sizes as of the last update.</summary>
-    private readonly IDictionary<Item, int> StackSizes;
+    private readonly Dictionary<Item, int> StackSizes = [];
 
     /// <summary>Items added since the last update.</summary>
     private readonly HashSet<Item> Added = new(new ObjectReferenceComparer<Item>());
@@ -46,9 +45,11 @@ internal class ChestTracker : IDisposable
         this.Chest = chest;
         this.InventoryWatcher = WatcherFactory.ForInventory($"{name}.{nameof(chest.Items)}", chest.Items);
 
-        this.StackSizes = this.Chest.Items
-            .Where(n => n != null)
-            .ToDictionary(n => n, n => n.Stack);
+        foreach (Item? item in this.Chest.Items)
+        {
+            if (item is not null)
+                this.StackSizes[item] = item.Stack;
+        }
     }
 
     /// <summary>Update the current values if needed.</summary>

src/SMAPI/Framework/StateTracking/PlayerTracker.cs

@@ -16,10 +16,10 @@ internal class PlayerTracker : IDisposable
     ** Fields
     *********/
     /// <summary>The player's inventory as of the last reset.</summary>
-    private IDictionary<Item, int> PreviousInventory;
+    private readonly Dictionary<Item, int> PreviousInventory;
 
     /// <summary>The player's inventory change as of the last update.</summary>
-    private IDictionary<Item, int> CurrentInventory;
+    private readonly Dictionary<Item, int> CurrentInventory = [];
 
     /// <summary>The player's last valid location.</summary>
     private GameLocation? LastValidLocation;
@@ -50,7 +50,7 @@ internal class PlayerTracker : IDisposable
     {
         // init player data
         this.Player = player;
-        this.CurrentInventory = this.GetInventory();
+        this.SaveInventoryTo(this.CurrentInventory);
         this.PreviousInventory = new Dictionary<Item, int>(this.CurrentInventory);
 
         // init trackers
@@ -81,16 +81,21 @@ internal class PlayerTracker : IDisposable
             watcher.Update();
 
         // update inventory
-        this.CurrentInventory = this.GetInventory();
+        this.CurrentInventory.Clear();
+        this.SaveInventoryTo(this.CurrentInventory);
     }
 
     /// <summary>Reset all trackers so their current values are the baseline.</summary>
     public void Reset()
     {
+        // reset watchers
         foreach (IWatcher watcher in this.Watchers)
             watcher.Reset();
 
-        this.PreviousInventory = this.CurrentInventory;
+        // reset PreviousInventory to match current
+        this.PreviousInventory.Clear();
+        foreach ((Item item, int stack) in this.CurrentInventory)
+            this.PreviousInventory.Add(item, stack);
     }
 
     /// <summary>Get the player's current location, ignoring temporary null values.</summary>
@@ -105,8 +110,8 @@ internal class PlayerTracker : IDisposable
     /// <returns>Returns whether anything changed.</returns>
     public bool TryGetInventoryChanges([NotNullWhen(true)] out SnapshotItemListDiff? changes)
     {
-        ISet<Item> added = new HashSet<Item>(new ObjectReferenceComparer<Item>());
-        ISet<Item> removed = new HashSet<Item>(new ObjectReferenceComparer<Item>());
+        HashSet<Item> added = new(new ObjectReferenceComparer<Item>());
+        HashSet<Item> removed = new(new ObjectReferenceComparer<Item>());
         foreach (Item item in this.PreviousInventory.Keys.Union(this.CurrentInventory.Keys))
         {
             if (!this.PreviousInventory.ContainsKey(item))
@@ -133,10 +138,13 @@ internal class PlayerTracker : IDisposable
     ** Private methods
     *********/
     /// <summary>Get the player's current inventory.</summary>
-    private IDictionary<Item, int> GetInventory()
+    /// <param name="inventory">The dictionary to fill with the player's inventory.</param>
+    private void SaveInventoryTo(Dictionary<Item, int> inventory)
     {
-        return this.Player.Items
-            .Where(n => n != null)
-            .ToDictionary(n => n, n => n.Stack);
+        foreach (Item? item in this.Player.Items)
+        {
+            if (item is not null)
+                inventory[item] = item.Stack;
+        }
     }
 }