SOLID

It's like Liquid but in C#.

Prelude

Source-generating C# files isn't a trivial task, partially due to how inconvenient the standard StringBuilder is. A typical source generated file requires you to chain a tonne of Append and AppendLine calls, completely obfuscating the real structure of the output file: consider, for example, the standard System.Text.Json context generator or Andrew Lock's wonderful NetEscapades.EnumGenerators.

SOLID provides an alternative approach to generating source files and building complex strings by utilising a custom interpolated string handler, which implements indentation controls, conditional If/Else/End blocks, as well as For loops.

Example

Consider the following.

code.Append(
    $"""
     {If(ingredients.Length > 0)}
     Recipe:
         {For(ingredients.Select(x => $"- {x}")):\n:}
     {Else}
     No ingredients? 🥺
     {End}
     """);

Given a list of ingredients that contains "banana", "oats", and "milk", the example above will produce:

Recipe:
    - banana
    - oats
    - milk

For an empty list of ingredients, it will produce:

No ingredients? 🥺

Breakdown

Code

code is a variable of type Code, the main class in SOLID. It is a simple wrapper around the standard StringBuilder, which handles indentation and interpolation.

If/Else/End

If, Else, and End are the main control blocks, which are used to handle conditional logic within SOLID interpolation templates, and they behave exactly like what you would expect from a standard if/else block in C#.

In the example above, the first If branch of the conditional will only be appended to the code if ingredients.Length > 0 is true; otherwise, the alternative Else branch will be appended. This allows you to control what to append within the interpolated SOLID template itself, instead of branching the logic outside of the template and chaining multiple Append calls.

For

For allows looping over a collection of items and appending each one of them to the code, with the format parameter :\n: indicating the separator character to insert between the items. The indentation before the For loop defines the indentation of every item in the collection.

In the example above, For will append every item in the list, separated by \n, with indentation level of 4.

Note

If, Else, End, and For are defined in the static Solid.Templates.Controls.Fluent class, which you can import via using static.

Licence

The project is licensed under the MIT license.