Rebol Programming/Design Guide/Use the shell

The command shell is a good way to test an idea or find a quick answer about a function.

In the shell, you can quickly display information about a particular function and its arguments.

In addition the SOURCE function can show you how other functions are written.

>> help func USAGE: FUNC spec body DESCRIPTION: Defines a user function with given spec and body. FUNC is a function value. ARGUMENTS: spec -- Help string (opt) followed by arg words (and opt type and string) (Type: block) body -- The body block of the function (Type: block) (SPECIAL ATTRIBUTES) catch

>> source func func: func [ "Defines a user function with given spec and body." [catch] spec [block!] {Help string (opt) followed by arg words (and opt type and string)} body [block!] "The body block of the function" ][   throw-on-error [make function! spec body] ]