bournish: Allow compilation of multiple expressions.

* guix/build/bournish.scm (%bournish-language): Add a joiner to SCHEME.
Compile only to Scheme.
* tests/bournish.scm: New file.
* Makefile.am (SCM_TESTS): Add it.

1 files changed, 15 insertions, 2 deletions

diff --git a/guix/build/bournish.scm b/guix/build/bournish.scm
index 3bea1c80c2..1f17e0a22d 100644
--- a/guix/build/bournish.scm
+++ b/guix/build/bournish.scm
@@ -149,11 +149,24 @@ code as an sexp."
 
 (define %bournish-language
   (let ((scheme (lookup-language 'scheme)))
+    ;; XXX: The 'scheme' language lacks a "joiner", so we add one here.  This
+    ;; allows us to have 'read-bournish' read one shell statement at a time
+    ;; instead of having to read until EOF.
+    (set! (language-joiner scheme)
+      (lambda (exps env)
+        (match exps
+          (()   '(begin))
+          ((exp) exp)
+          (_    `(begin ,@exps)))))
+
     (make-language #:name 'bournish
                    #:title "Bournish"
+
+                   ;; The reader does all the heavy lifting.
                    #:reader read-bournish
-                   #:compilers (language-compilers scheme)
-                   #:decompilers (language-decompilers scheme)
+                   #:compilers `((scheme . ,(lambda (exp env options)
+                                              (values exp env env))))
+                   #:decompilers '()
                    #:evaluator (language-evaluator scheme)
                    #:printer (language-printer scheme)
                    #:make-default-environment