Warning: This is the manual of the legacy Guile 2.0 series. You may want to read the manual of the current stable series instead.

6.23.1 Using Other Languages

There are currently only two ways to access other languages from within Guile: at the REPL, and programmatically, via compile, read-and-compile, and compile-file.

The REPL is Guile’s command prompt (see Using Guile Interactively). The REPL has a concept of the “current language”, which defaults to Scheme. The user may change that language, via the meta-command ,language.

For example, the following meta-command enables Emacs Lisp input:

scheme@(guile-user)> ,language elisp
Happy hacking with Emacs Lisp!  To switch back, type `,L scheme'.
elisp@(guile-user)> (eq 1 2)
$1 = #nil

Each language has its short name: for example, elisp, for Elisp. The same short name may be used to compile source code programmatically, via compile:

elisp@(guile-user)> ,L scheme
Happy hacking with Guile Scheme!  To switch back, type `,L elisp'.
scheme@(guile-user)> (compile '(eq 1 2) #:from 'elisp)
$2 = #nil

Granted, as the input to compile is a datum, this works best for Lispy languages, which have a straightforward datum representation. Other languages that need more parsing are better dealt with as strings.

The easiest way to deal with syntax-heavy language is with files, via compile-file and friends. However it is possible to invoke a language’s reader on a port, and then compile the resulting expression (which is a datum at that point). For more information, See Compilation.

For more details on introspecting aspects of different languages, See Compiler Tower.