transform: handle ./source.

gash/grammar.scm

@@ -245,6 +245,8 @@
     (('compound compound) (transform compound))
     (('compound compound ...) `(begin ,@(map transform compound)))
 
+    (('command (word (or "." "source")) file-name)
+     `(source ,(transform file-name)))
     (('command word ... ('io-redirect ('io-here "<<" ('io-here-document string))))
      `(pipeline (cut display ,string) (command ,@word)))
     (('command word ... ('io-redirect filedes ... ('io-file ">" file-name)))

gash/script.scm

@@ -59,6 +59,7 @@
             script-status
             sequence
             singlequotes
+            source
             splice
             split
             substitution
@@ -72,6 +73,11 @@
     (('pipeline command) (pke 'background: `(pipeline+ #f ,command)))
     (_ term)))
 
+(define (source file-name)
+  (let* ((string (with-input-from-file file-name read-string))
+         (ast (parse-string string)))
+    (run ast)))
+
 (define (command . args)
   (define (exec command)
     (cond ((procedure? command) command)