main

docs/document/Articles/docs/Make Nix Derivation.md

@@ -0,0 +1,13 @@
+# Make Nix Derivation
+
+Making a nix derivation typically includes following steps.
+
+1. **Choose a derivation function**: `pkgs` has some wrapper functions of `mkDerivation` for different frameworks. See:[Languages and Frameworks](https://nixos.org/manual/nixpkgs/stable/#chap-language-support)  
+  - `mkDerivation` is a wrapper of `derivation` function.
+2. **Find a source**: where the source code come from? github repo or tarball or any other available from url.
+  - If the source is precompiled, should set a appropriate value for `meta.sourceProvenance`. See: [Source provenance](https://ryantm.github.io/nixpkgs/stdenv/meta/#sec-meta-sourceProvenance) 
+3. **Choose a fetcher**: use a appropriate fetcher to download the source. See [Fetchers](https://nixos.org/manual/nixpkgs/unstable/#chap-pkgs-fetchers) 
+4. **Generate lock file**: if you'd build from source, this might require a lock file so nix can download dependencies during build.
+  - If the source is precompiled, this is probably not necessary.
+  - Lock file is typically required when using a wrapper function of `mkDerivation` for certain framework.
+5. 

docs/document/PowerShell/docs/Language/Array.md

@@ -221,6 +221,19 @@ Keyword operators has special functionalities on collections.
 > [!NOTE]
 > If current item for `-match` or `-notmatch` is not a string, Powershell evaluates it to string by certain strategy.
 
+> [!TIP]
+> Match and replace is case-insensitive by default. Use `-cmatch`, `-cnotmatch`, `-creplace`, `-csplit` for **case-sensitive** scenarios.
+
+## Deconstruction
+
+```ps1
+$a, $b, $c = 1,2,3 # $a = 1, $b = 2, $c = 3
+$a, $b = 1,2,3 # $a = 1, $b = 3 This might not be expected # [!code warning] 
+```
+
+> [!WARNING]
+> You should only use deconstruction when **you need the first and the last item returned** or **you're pretty sure there's only two element will be returned**.
+
 ## Multi-Dim Array
 
 You'll have to create Multi-Dim array from .NET type constructor only.

docs/document/PowerShell/docs/Language/Control Flow.md

@@ -75,6 +75,25 @@ cd ..; gci -rec -file; echo hello
 
 In PowerShell 7, `&&` and `||` were introduced to do the same command chaining as bash does.
 
+## Null-Conditional Operator <Badge type="info" text="PowerShell 7+" />
+
+This feature is basically the same as in `C#` except a bracing `{}` is required around variable because `?` is valid as part of variable name.
+
+```ps1
+$null.Bar() # exception raised # [!code error] 
+${null}?.Bar() # ok
+
+$null[0] # exception raised here # [!code error] 
+${null}?[0] # ok
+
+$null ?? 'I am not null'
+
+$baz ??= 'I am new value'
+```
+
+## Ternary Operator <Badge type="info" text="PowerShell 7+" />
+
+No need to explain, same as in `C#`.
 
 ## Pattern Matching
 

docs/document/PowerShell/docs/Language/String.md

@@ -21,7 +21,7 @@ Use `$` to interpolate:
 ```
 
 > [!NOTE]
-> `$()` is being called **SubExpression Operator** in Powershell.
+> `$()` is being called **SubExpression Operator** in PowerShell.
 
 ## Verbatim String
 
@@ -36,12 +36,12 @@ Can contains new lines and
 ```
 
 > [!NOTE]
-> Verbatim string does not allow interpolation in Powershell which differs from `C#`.
+> Verbatim string does not allow interpolation in PowerShell which differs from `C#`.
 
 ## Raw String
 
 > [!NOTE]
-> Raw string is being called **Here String** in Powershell.
+> Raw string is being called **Here String** in PowerShell.
 
 **Here String** typically allows string contents starting at the second line and truncates the last newline.
 
@@ -93,7 +93,7 @@ Use double `'` to escape `'` in a verbatim string.
 
 ## Arithmetic with Numerics
 
-Powershell will try to convert the string on the right operand to the same type as left operand.
+PowerShell will try to convert the string on the right operand to the same type as left operand.
 Exception will be raised if conversion failed.
 
 ```ps1
@@ -111,6 +111,15 @@ Exception will be raised if conversion failed.
 
 ## Match & Replace
 
+PowerShell has two kinds of matching strategy for strings.
+- `-match` for regex matching.
+- `-like` for wildcard matching.
+
+While `-replace` only supports regex.
+
+> [!TIP]
+> Match and replace is case-insensitive by default. Use `-cmatch`, `-cnotmatch`, `-creplace`, `-csplit` for **case-sensitive** scenarios.
+
 ```ps1
 'Janet is a girl' -match 'Jane' # True
 'Janet is a girl' -replace '^Janet', 'Jane'

docs/document/PowerShell/docs/Object Manipulation/ForEach.md

@@ -25,8 +25,13 @@ If you do want a `$null` return, use `Out-Null` to swallow the value.
 
 ```ps1
 # doesn't make much sense though
-(gci | foreach { $_.Name | Out-Null }) -eq $null # True
+$null -eq (gci | foreach { $_.Name | Out-Null }) # True
 ```
 
-
+> [!NOTE]
+> One exception is `ForEach-Object` can execute method by name.
+> You might expect delegate objects to be returned, but no, values of the method being executed will be returned.
+>```ps1
+>(1,2,3 | % GetType | select -first 1) -is [System.Type] # True
+>```
 

docs/document/PowerShell/docs/Object Manipulation/Select.md

@@ -1,6 +1,8 @@
 # Select
 
-## Overview
+`Select-Object` serves for multiple purposes for object transformation and picking from collection.
+
+The following is a overview:
 
 - Picking composed object by one or more properties with `-Property`.
     - select properties reversely by `-ExcludeProperty`.

docs/document/PowerShell/docs/Terminology.md

@@ -3,7 +3,7 @@
 Powershell has its own terminologies besides other shells like bash.
 It's a shell integrated with .NET, it's not a independent platform.
 
-- `cmdlet`: builtin utils inside powershell, implemented using other languages like `C#`.
+- `cmdlet`: precompiled .NET assemblies work for PowerShell, implemented using other languages typically in `C#`.
 - `function`: a command implemented using powershell language itself.
 - `application`: external executable.
 

docs/document/PowerShell/docs/Type System/Extended Type System.md

@@ -1,11 +1,49 @@
 # Extended Type System
 
-Extended Type System(ETS) is for consistent experience with **some** `.NET` types when working with Powershell.
+Extended Type System(ETS) is for consistent experience with **some** `.NET` types when working with PowerShell.
 
-For this purpose, Powershell wraps the traget object as `PSObject` with two approaches:
+There's two approaches that PowerShell did for implementing the ETS.
 
-- Set the object to be wrapped as a meta object(similar to lua metatable)
-- Add extra members to the containing `PSObject` itself.
+- Intrinsic members for all objects.
+- Dynamic manipulation to members of an object.
+- Potentially wrap an object as `PSObject`.
+
+## Intrinsic Members
+
+There's two kinds of intrinsic members in PowerShell
+- Object views: the mapping of a certain object.
+- Property and methods: intrinsic properties and methods.
+
+All objects in PowerShell have five **object views** members:
+
+- `psobject`: a `MemberSet` containing reflection source of members.
+```ps1
+$foo = 'I am foo'
+[object]::ReferenceEquals($foo, $foo.psobject.BaseObject) # True
+```
+- `psbase`: a `MemberSet` containing members of the object being wrapped.
+```ps1
+$foo = 'I am foo'
+[object]::ReferenceEquals($foo.ToString, $foo.psbase.ToString) # True
+```
+- `psadapted`: a `MemberSet` containing adapted members added by ETS.
+- `psextended`: a `MemberSet` containing extended members **added at runtime**.
+- `pstypenames`: a `CodeProperty` equivalent to `psobject.TypeNames`. Returns a collection containing the type names of inheritance chain.
+```ps1
+$foo = 'I am foo'
+[object]::ReferenceEquals($foo.psobject.TypeNames, $foo.pstypenames) # True
+```
+
+Intrinsic methods and properties are to mimic singular object and collection in a same form.
+- `Where`: a method for filtering or slicing by condition. See [Where](../Object Manipulation/Where.md) 
+- `ForEach`: a method to perform iteration with certain logic or perform casting all items to target type. See [ForEach](../Object Manipulation/ForEach.md) 
+- `Count`
+- `Length`
+
+
+> [!NOTE]
+>**Intrinsic members are not described as part of certain type definition, they're isolated from the object-oriented type system.**
+> Object views are visible to `Get-Member -Force` while intrinsic methods aren't.
 
 A common example would be `Process` type.
 
@@ -16,18 +54,16 @@ A common example would be `Process` type.
 (gps | select -First 1) -is [System.Diagnostics.Process] # True
 ```
 
-The functionality of ETS achieved benifits:
+The functionality of ETS achieved benefits:
 
-- Allow custom behaviours like formatting, sorting for your custom type or object.
+- Allow custom behaviors like formatting, sorting for your custom type or object.
 - Dynamic interpreting a `HashTable` to any `PSObject`
 - Accessibility to the underlying object.
 - Manipulation on extended members.
 
-## What's `PSObject`
-
 ## ETS Members
 
-To represent meta of ETS members, Powershell has an abstract class called `PSMemberInfo`, each concrete member info type is derived from it.
+To represent meta of ETS members, PowerShell has an abstract class called `PSMemberInfo`, each concrete member info type is derived from it.
 
 ```cs
 public abstract class PSMemberInfo { }
@@ -37,4 +73,3 @@ public abstract class PSMemberInfo { }
 The facts of ETS members:
 - each member has a type inherited from `PSMemberInfo`.
 
-## PSObject