The Interactive Gerbil Shell

The interactive shell that you get when you run gxi is a larger environment than the Gerbil core language. It imports the :gerbil/gambit prelude and also provides some functionality that is mainly useful for interactive development.

Interactive Development Macros

These macros are only available in the interactive shell

(reload module-path ...)

Reloads the module given by the module path and then imports the freshly reloaded module. The module path is the same as you would use in a import form; a string will reload a source loaded module while a library module path will reload a compiled module as applicable in the load path. Top defined modules are ignored.

(enter! module-path)

Starts a repl using the sytnactic context of a given module, which is first evaluated.

(@expand form)
(@expand1 form)

These two macros perfom macro expansion, preety print the result, and return the quoted expanded syntax for inspection. The difference lies in the function used to perform the expansion. @expand uses core-expand* which expands until the outer form is a core macro. @expand1 uses core-expand1 which performs a single step expansion.

Customizing the Interactive Shell

Whenever gxi is run interactively, after loading and initializing the runtime and expander, it loads the library interactive initialization file $GERBIL_HOME/lib/init.ss (source: init.ss) which greets the user, imports the :gerbil/gambit prelude module and provides the interactive development forms documented above.

After loading the library initialization file, gxi checks for a user specific interactive initialization file. If the file ~/.gerbil/init.ss exists, then it is loaded in the top (interaction) environment. This allows you to customize your interactive Gerbil shell.

Here is a small example ~/.gerbil/init.ss that provides useful functionality:

;;; -*- Gerbil -*-

;; add your work environment's source tree to the load path
(add-load-path "/path/to/your/gerbil/project/src")

;; only useful if you intend to do core Gerbil development
;; (add-load-path (path-expand "src" (getenv "GERBIL_HOME")))

;; import your personal gerbil libraries
(import :my/stuff :more/of/my/stuff)