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