How do I use swift in Terminal?

I read What's new in Xcode 6. The article introduces some new feature about Xcode 6, and it says:

Command Line

Xcode’s debugger includes an interactive version of the Swift language, known as the REPL (Read-Eval-Print-Loop). Use Swift syntax to evaluate and interact with your running app or write new code in a script-like environment. The REPL is available from within LLDB in Xcode’s console, or from Terminal.

I want to know how to get the REPL?

sudo xcode-select -switch /Applications/

then you can do one of these:

xcrun swift
lldb --repl

As of Xcode 6.1 - typing swift in the terminal launches the REPL as well.