Change new Slice() so C# compiler can infer type arguments

Also fix something resembling a bug in BList/BDictionary/BMultiMap

Core/AssemblyVersion.cs

@@ -14,5 +14,5 @@
 // command to change the version number which, I guess, produces an incompatible 
 // assembly in the presence of strong names (strong naming prevents two assemblies 
 // from linking together without an exact match.)
-[assembly: AssemblyVersion("2.7.1.4")]
-[assembly: AssemblyFileVersion("2.7.1.4")]
+[assembly: AssemblyVersion("2.7.1.5")]
+[assembly: AssemblyFileVersion("2.7.1.5")]

Core/Loyc.Collections/ALists/BListInner.cs

@@ -42,6 +42,8 @@ protected BListInner(BListInner<K, T> original, uint index, uint count, AListBas
 		#endregion
 
 		/// <summary>Stores the highest key that applies to the node with the same index.</summary>
+		/// <remarks>The highest key of the rightmost node is not tracked (can't remember 
+		/// why not - maybe just because it is traditional not to track it in B+ trees.)</remarks>
 		protected K[] _highestKey;
 
 		public override long CountSizeInBytes(int sizeOfT, int sizeOfK) =>
@@ -140,12 +142,26 @@ internal override int DoSingleOperation(ref AListSingleOperation<K, T> op, out A
 							flagParent = true;
 						}
 					}
+					else if (i + 1 == LocalCount && i > 0 && _children[i].Node.LocalCount == 0)
+					{   // (2020/03 fix) The last item in the last node was removed, so the highest 
+						// key of this node may have decreased. AssertValid() failed in the parent
+						// on rare occasions when the max node size was 3, because the parent node 
+						// could have a _highestKey value that was too high. No malfunctions were 
+						// observed as a result, and I'm hard pressed to think of anything that 
+						// could go wrong when the highest-key value is too high but lower than the 
+						// next sibling. Note: don't update _highestKey[i] here because the highest 
+						// key of the final node is never tracked.
+						Debug.Assert(sizeChange == -1);
+						flagParent = true;
+						op.AggregateChanged |= 1;
+						op.AggregateKey = GetHighestKey(_children[i - 1].Node);
+					}
 
 					if (splitLeft.IsUndersized)
 						flagParent |= HandleUndersized(i, tob);
 
 					if (flagParent)
-						splitLeft = this;
+						splitLeft = this; // inform parent about highest-key change or undersized node
 					else
 						splitLeft = null;
 				}

Core/Loyc.Essentials/Collections/Adapters/ROLSlice.cs

@@ -9,8 +9,11 @@ namespace Loyc.Collections
 {
 	public static partial class ListExt
 	{
-		public static ROLSlice<TList, T> Slice<TList, T>(this TList list, int start, int count = int.MaxValue) where TList : IReadOnlyList<T>
-			=> new ROLSlice<TList, T>(list, start, count);
+		// C# generally can't infer the arguments
+		//public static ROLSlice<TList, T> Slice<TList, T>(this TList list, int start, int count = int.MaxValue) where TList : IReadOnlyList<T>
+		//	=> new ROLSlice<TList, T>(list, start, count);
+		public static ROLSlice<IReadOnlyList<T>, T> Slice<T>(this IReadOnlyList<T> list, int start, int count = int.MaxValue)
+			=> new ROLSlice<IReadOnlyList<T>, T>(list, start, count);
 	}
 
 	/// <summary>Adapter: a random-access range for a slice of an <see cref="IReadOnlyList{T}"/>.</summary>

Main/LeMP/MacroProcessorTask.cs

@@ -770,15 +770,15 @@ private void GetApplicableMacros(LNode curNode, List<InternalMacroInfo> foundMac
 							for (j = i + 1; j < foundMacros.Count; j++)
 								if (foundMacros[j].Attr.Priority != p)
 									break;
-							var newNode = ApplyMacrosFound2(s, foundMacros.Slice(i, j - i));
+							var newNode = ApplyMacrosFound2(s, ((IList<InternalMacroInfo>)foundMacros).Slice(i, j - i));
 							if (newNode != null)
 								return newNode;
 						}
 						return null;
 					}
 				}
 			}
-			return ApplyMacrosFound2(s, foundMacros.Slice(0));
+			return ApplyMacrosFound2(s, ((IList<InternalMacroInfo>)foundMacros).Slice(0));
 		}
 
 		private MacroResult? ApplyMacrosFound2(CurNodeState s, ListSlice<InternalMacroInfo> foundMacros)

appveyor.yml

@@ -12,7 +12,7 @@ before_build:
 build_script:
     # First, set some environment variables.
     # SEMVER is set manually. Not sure how this can be automated.
-    - set SEMVER=27.1.4
+    - set SEMVER=27.1.5
     - echo %APPVEYOR_REPO_TAG%
     # Build packages as SEMVER-ci{build}
     - ps: if ($env:APPVEYOR_REPO_TAG -eq $True) { $env:PKG_VERSION = $env:SEMVER; } else { $env:PKG_VERSION = "$($env:SEMVER)-ci$($env:APPVEYOR_BUILD_NUMBER)"; }