Planck Namespaces

In order to make Planck more useful for doing actual work and interacting with your computer and the outside world, some native I/O facilities have been added to the JavaScriptCore instance running in Planck and these have been exposed via a few namespaces. To make things easier to use, the functions in these namespaces adhere fairly closely to existing Clojure / ClojureScript analogs.

The code for these namespaces is included directly in the Planck binary, so they are always available—you just need to require them.

These namespaces comprise

• planck.core
• planck.environ
• planck.http
• planck.io
• planck.repl
• planck.shell

To explore these namespaces, you can evaluate (dir planck.core), for example, to see the symbols in planck.core, and then use the doc macro to see the docs for any of the symbols.

planck.core

This namespace primarily collects functions that are part of Clojure's clojure.core but are not part of ClojureScript. This includes basic I/O capabilities like slurp, spit and read-line as well as functions useful for console scripting like file-seq (directory listing), read-password (password input) and exit (exit values).

The I/O facilities are expressed in protocols defined in planck.core modeled after those in Clojure, like IReader, IOutputStream, etc., and these capabilities cooperate with facilities defined in planck.io.

The planck.core namespace also defines dynamic functions like resolve, ns-resolve, and intern. Some dynamic vars of interest like *in* and *out* are defined here as well.

planck.environ

This namespace provided access to environment variables, modeled after Environ. For example

(:home planck.environ/env)

will access the HOME environment variable.

planck.http

This namespace provides facilities for interacting with HTTP servers. For example:

(planck.http/get "https://planck-repl.org")

will fetch the main page of the Planck website, returning the status code, headers, and body in a map structure.

planck.io

This namespace defines a lot of the IOFactory machinery, imitating clojure.java.io. File system facilities like file, delete-file, and file-attributes are also made available.

planck.repl

This namespace includes a few macros that are useful when working at the REPL, such as doc, dir, source, etc.

planck.shell

This namespace imitates clojure.shell, and defining the sh function and with-sh-dir / with-sh-env macros that can be used to execute external command-line functions.

With this escape hatch, you can do nearly anything: move files to remote hosts using scp, etc.