RFC for String Manipulating Cmdlets

X-Withdrawn/RFC0054-String-Manipulating-Cmdlets.md

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+---
+RFC: '0054'
+Author: Friedrich Weinmann
+Status: Withdrawn
+SupercededBy: n/a
+Version: 1.0
+Area: cmdlets/data manipulation
+Comments Due: 
+Plan to implement: Yes
+---
+
+# String Manipulating Cmdlets
+
+Add cmdlets that manipulate strings and are capable of doing so on the pipeline.
+
+## Motivation
+
+Existing tools to manipulate strings - the most common data type manipulated in PowerShell are lacking in usability.
+The .NET tools available through string and regex are inconvenient to use.
+String-manipulating operators (such as `-split`) are unintuitive to explore, as their options are not easily discoverable.
+Neither option allows use on the pipeline, forcing interruption of the pipeline or use of inefficient `ForEach-Object` calls.
+
+From this come two main pain points this RFC is aimed to resolve:
+
+Current string data manipulation ...
+
+ - is technically insufficient from a performance perspective.
+ - is unintuitive and inconvenient for the end user.
+
+Given that this is a universal problem affecting literally all users and most code, this should be implemented as part of the core application, not an external third party module.
+
+## Specification
+
+### New Cmdlets
+
+The solution should provide cmdlets that allow string manipulation on the pipeline.
+
+The following operations should be supported:
+
+ - `Add-String`    | Implements partial `-f` functionality to add content to strings, as well as the `.PadLeft()` and `.PadRight()` methods.
+ - `Format-String` | Implements full `-f` functionality or the `String.Format()` method. Supports gathering multiple items from the pipeline before formatting.
+ - `Get-SubString` | Implements the `.SubString()` method, the `-Trim` operator as well as the `.TrimStart()` and `.TrimEnd()` methods.
+ - `Join-String`   | Implements the `-join` operator, allowing specifying the number of items to join in each batch.
+ - `Set-String`    | Implements the `-Replace` operator as well as the `.Replace()` method.
+ - `Split-String`  | Implements the `-Split` operator as well as the `.Split()` method.
+
+### New Aliases
+
+Given that part of the goal is to improve the user experience, introducing aliases - especially for those mapping operators where users are used to it - will improve user experience and accelerate adoption.
+
+Thus here a proposed list of aliases:
+
+ - `Add-String`    | `wrap` or `add`
+ - `Format-String` | `format`
+ - `Get-SubString` | None needed - `substring` will automatically resolve to `Get-SubString`
+ - `Join-String`   | `join`
+ - `Set-String`    | `replace`
+ - `Split-String`  | `split`
+
+## Alternate Proposals and Considerations
+
+### Distribution as part of a module
+
+Theoretically, these cmdlets could also be released and distributed as part of an external module.
+
+The same could really be said of every single cmdlet that is shipped as part of the core PowerShell.
+What makes a cmdlet core then?
+Not bound to a specific use-case? Check.
+Relevant to the vast majority of users? Check. (In fact vastly more so than quite a few other core cmdlets)
+
+### Status Quo
+
+The status quo - having users keep using operators and .NET methods -would have several disadvantages:
+
+ - More coding effort to use
+ - Additional resource cost (memory when interrupting pipeline, CPU when using `ForEach-Object` instead)
+ - Harder to maintain code
+ - Less discoverability for users
+ - Harder to find documentation for users
+
+## Notes:
+
+ - This topic has already been discussed in an issue](https://github.com/PowerShell/PowerShell/issues/6697)
+ - For an experimental implementation, [see the following PR](https://github.com/PowerShell/PowerShell/pull/6753)