Where can I find a list of Powershell .NET Type Accelerators?

Question

In PowerShell you can use [xml] to mean [System.Xml.XmlDocument]. Do you know where I can find a list of these type accelerators?

Are these accelerators specific to PowerShell or .NET?

Answer 1

See the section entitled Type Name Aliases in this blog post. I believe this is a complete list of the aliases.

PowerShell Type Alias   Corresponding .NET Type
[int]                   System.Int32
[int[]]                 System.Int32[]
[long]                  System.Int64
[long[]]                System.Int64[]
[string]                System.String
[string[]]              System.String[]
[char]                  System.Char
[char[]]                System.Char[]
[bool]                  System.Boolean
[bool[]]                System.Boolean[]
[byte]                  System.Byte
[byte[]]                System.Byte[]
[double]                System.Double
[double[]]              System.Double[]
[decimal]               System.Decimal
[decimal[]]             System.Decimal[]
[float]                 System.Single
[single]                System.Single
[regex]                 System.Text.RegularExpression.Regex
[array]                 System.Array
[xml]                   System.Xml.XmlDocument
[scriptblock]           System.Management.Automation.ScriptBlock
[switch]                System.Management.Automation.SwitchParameter
[hashtable]             System.Collections.Hashtable
[psobject]              System.Management.Automation.PSObject
[type]                  System.Type
[type[]]                System.Type[]

Answer 2

@Noldorin has a good list of some of the Type Accelerators, with some.

PowerShell also allows you to use type literals to cast objects, call static methods, access static properties, reflect over, and anything else you might do with an instance of a System.Type object.

In order to use a type literal, you just enclose the full name (namespace and class name) of the class (or struct or enum) (with a period separating the namespace and the class name) enclosed in brackets like:

[System.Net.NetworkInformation.IPStatus]

PowerShell will also provide a leading "System." in its attempt to resolve the name, so you don't need to explicitly use that if you are using something in a System* namespace.

[Net.NetworkInformation.IPStatus]

Oisin Grehan (a PowerShell MVP) also has a blog post about creating your own type accelerators.

Answer 3

The definitive way is to do what Oisin demontrates in this excellent blog post:

PS> $acceleratorsType = [type]::gettype("System.Management.Automation.TypeAccelerators")
PS> $acceleratorsType

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
False    False    TypeAccelerators                         System.Object


PS> $acceleratorsType::Add("accelerators", $acceleratorsType)
PS> [accelerators]::Get

Key                                                         Value
---                                                         -----
int                                                         System.Int32
...

Note that you have to add the new 'accelerators' accelerator to the dictionary because the TypeAccelerators type is not public. Amazing what you can do with .NET Reflector and a lot of spare time. :-) You rock Oisin!

Answer 4

What does it mean when there are two brackets in front of the type name (ex. [byte[]])?