Installation

Fickl is a .NET tool. It needs the .NET SDK 10 or later, and Node.js or a browser to run what it produces.

Install the compiler

Install it in the project's tool manifest, so everyone on the project uses the same version:

dotnet new tool-manifest
dotnet tool install fickl

The command is dotnet fickl. It takes the same arguments as dotnet fable.

Compile a project

Point it at a project file or its folder. -o sets the output folder:

dotnet fickl src/App.fsproj -o dist

Each .fs file compiles to a .js file in dist, and the runtime library is copied to dist/fable_modules. Run the compiler in watch mode while you work:

dotnet fickl watch src/App.fsproj -o dist

TypeScript is a language choice, and declaration files are a flag on JavaScript output:

dotnet fickl src/App.fsproj -o dist --lang ts
dotnet fickl src/App.fsproj -o dist --declaration

Compiler flags lists the rest.

To compile as part of dotnet build instead, use the Fickl.Sdk package: see Compiling with dotnet build.

Add Fickl.Core

Fable.Core keeps working. Fickl's own attributes, computation expressions and bindings are in the Fickl.Core package:

dotnet add src/App.fsproj package Fickl.Core

Open Fickl.Core in a file to use them. Its version matches the compiler's, so update both together.

Coming from Fable

Replace dotnet fable with dotnet fickl in your scripts. Nothing else has to change: your project file, your packages and your attributes stay the same. Fickl's own behaviour changes are opt-in, through flags and through attributes in the Fickl namespaces; Compatibility explains how to write code that compiles with both.