built-ins: read: Port to Mes.

* gash/built-ins/read.scm (define-module): Import SRFI 14.
(right-pad): New procedure.
(main): Use it in place of a 'circular-list' trick.

gash/built-ins/read.scm

@@ -23,6 +23,7 @@
   #:use-module (gash environment)
   #:use-module (ice-9 match)
   #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-14)
   #:use-module (srfi srfi-26))
 
 ;;; Commentary:
@@ -84,6 +85,12 @@ field, while contiguous sequences of characters from the set
                        (reverse! (cons field acc)))))))))
    (else '())))
 
+(define (right-pad lst n)
+  (let ((m (length lst)))
+    (if (< m n)
+        (append lst (make-list (- n m) ""))
+        lst)))
+
 (define (main . args)
   (match-let* (((vars . get-line)
                 (match args
@@ -102,7 +109,7 @@ field, while contiguous sequences of characters from the set
                 ;; XXX: Verify that VAR is a valid variable name.
                 (setvar! var field))
               vars
-              (append fields (circular-list "")))
+              (right-pad fields (length vars)))
     (if (eof-object? delimiter)
         EXIT_FAILURE
         EXIT_SUCCESS)))