MicroElements.Collections.Sources 1.10.0

The ID prefix of this package has been reserved for one of the owners of this package by NuGet.org. Prefix Reserved
dotnet add package MicroElements.Collections.Sources --version 1.10.0
NuGet\Install-Package MicroElements.Collections.Sources -Version 1.10.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="MicroElements.Collections.Sources" Version="1.10.0">
  <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add MicroElements.Collections.Sources --version 1.10.0
#r "nuget: MicroElements.Collections.Sources, 1.10.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install MicroElements.Collections.Sources as a Cake Addin
#addin nuget:?package=MicroElements.Collections.Sources&version=1.10.0

// Install MicroElements.Collections.Sources as a Cake Tool
#tool nuget:?package=MicroElements.Collections.Sources&version=1.10.0



MicroElements source only package: Collection extensions: NotNull, Iterate, Execute, WhereNotNull, Materialize, IncludeByWildcardPatterns, ExcludeByWildcardPatterns. Special collections: Cache, TwoLayerCache, PollingCache.



Returns not null (empty) enumeration if input is null.

string? GetFirstValue(IEnumerable<string>? optionalValues) =>


Enumerates only not null values.

string?[] namesWithNulls = {"Alex", null, "John"};
string[] names = namesWithNulls.WhereNotNull().ToArray();


Iterates values and executes action for each value. It's like List.ForEach but works with lazy enumerations and does not forces additional allocations.

// Iterates values and outputs to console.
    .Range(1, 100_000)


Execute extension allows to execute an action on each value while enumerating the source enumeration.

This method is pure LINQ method, with postponed enumeration, also it can be chained.

    .Range(1, 10)


Materializes source enumeration and allows to see intermediate results without changing execute chain. MaterializeDebug is the same as Materialize but works only in Debug mode and does not affect performance for Release builds.

    .Range(1, 10)
    .Materialize(values => { /*set breakpoint here*/ })


Provides methods for wildcard or glob filtering.

See also: https://en.wikipedia.org/wiki/Glob_(programming).

public void WildcardInclude()
    string[] values = { "Microsoft.Extension.Logging", "Microsoft.AspNetCore.Hosting", "FluentAssertions", "System.Collections.Generic" };
    string[] includePatterns = { "Microsoft.AspNetCore.*", "*.Collections.*" };
    string[] result = { "Microsoft.AspNetCore.Hosting", "System.Collections.Generic" };
public void WildcardExclude()
    string[] values = { "Microsoft.Extension.Logging", "Microsoft.AspNetCore.Hosting", "FluentAssertions", "System.Collections.Generic" };
    string[] excludePatterns =  { "Microsoft.AspNetCore.*", "*.Collections.*" };
    string[] result = { "Microsoft.Extension.Logging", "FluentAssertions" };



Represents ThreadSafe cache that holds only limited number of items. Can be used as drop in replacement for ConcurrentDictionary.

Use it when you need simple cache but with memory limit.


  • Cache organized in two layers: hot and cold.
  • Items first added to cold cache.
  • GetValue first checks hot cache. If value not found in hot cache than cold cache uses for search.
  • If value exists in cold cache than item moves to hot cache.
  • If hot cache exceeds item limit then hot cache became cold cache and new hot cache creates.


Global ambient cache extensions. Represents ConcurrentDictionary of some type that is accessed by it's name.

Reason: Use cache from any place of your code without declaring cache (that's so boring and noisy). Best suited for global caches of immutable objects that never changes in application lifecycle.

// Static named cache
var value = Cache
    .Instance<string, string>("Example")
    .GetOrAdd("key1", k => VeryLongFetch(k));
// Cache attached to instance
var value = instance
    .GetWeakCache<string, string>(/*optional name*/)
    .GetOrAdd("key1", k => VeryLongFetch(k));
  • Cache instance is global so use proper cache instance names.
  • For static cache use some const name for example class name or method name
  • Can cause to memory leak if cache grows permanently. For such cases use caches that clears by time or size for example TwoLayerCache
  • Adds one more operation to find cache instance
  • It can be treated as some kind of an "AMBIENT CONTEXT" that becomes an anti-pattern. See: https://freecontent.manning.com/the-ambient-context-anti-pattern/
Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.1 is compatible. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (2)

Showing the top 2 NuGet packages that depend on MicroElements.Collections.Sources:

Package Downloads
MicroElements.Reflection.Sources The ID prefix of this package has been reserved for one of the owners of this package by NuGet.org.

MicroElements source only package: Reflection. Classes: TypeExtensions, TypeCheck, ObjectExtensions, Expressions, CodeCompiler, FriendlyName.

MicroElements.Shared.Sources The ID prefix of this package has been reserved for one of the owners of this package by NuGet.org.

MicroElements source packages metapackage.

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This package is not used by any popular GitHub repositories.

Version Downloads Last updated
1.10.0 356 10/22/2023
1.9.0 234 9/18/2023
1.7.0 413 2/25/2023
1.6.0 965 10/9/2022
1.5.0 517 6/4/2022
1.4.0 573 5/15/2022
1.3.0 1,745 1/12/2022
1.2.1 842 12/13/2021
1.2.0 787 12/11/2021
1.1.0 473 11/1/2021

# Changelog

## [1.10.0] - 2023-10-22
- PollingCache become async only, unified methods, more customizations
- TwoLayerCache fixed maxItemCount for cold cache

## [1.9.0] - 2023-09-17
- PollingCache provides caching that refreshes cached value on retrieve if value was expired
- TwoLayerCache added check for maxItemCount for cold cache

## [1.8.0] - 2023-05-25
- Added: WhereNotNull extension that enumerates only not null values
- Added: Execute extension that allows to execute an action on each value while enumerating the source enumeration

## [1.7.0] - 2023-02-25
- Added: Cache.GetWeakCache - special cache that attaches to instance with weak reference and can be released by GC after the host object release

## [1.6.0] - 2022-10-09
- Added: MicroElements.Collections.Extensions.WildCard. Methods: IsMatchesWildcard, IncludeByWildcardPatterns, ExcludeByWildcardPatterns
- Changed: Cache.Instance and TwoLayerCache.Instance methods unified and become typesafe.

## [1.5.0] - 2022-05-28
- Added: Cache.Instance - global static cache instance

## [1.4.0] - 2022-05-15
- Added: TwoLayerCache.Instance - global static cache instance

## [1.3.0] - 2022-01-12
- Changed: Fixed PureAttribute ambiguity in NotNull extension when JetBrains.Annotations referenced

## [1.2.0] - 2021-12-10
- Added: Materialize extensions
- Changed: TwoLayerCache: Interlocked increments for cache metrics
- Changed: MicroElements.CodeContracts.Sources bumped to 1.1.0

## [1.1.0] - 2021-10-17
- Added: Iterate extensions
- Added: TwoLayerCache
- Changed: Namespaces granularity on file level.

## [1.0.0] - 2021-10-14
- Added: NotNull extensions

Full release notes can be found at: https://github.com/micro-elements/MicroElements.Shared/blob/master/src/MicroElements.Collections.Sources/CHANGELOG.md