import: crate: Add '--recursive'.

* guix/scripts/import/crate.scm (show-help, guix-import-crate): Add '--recursive'.
* doc/guix.texi (Invoking guix import): Mention '--recursive'.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

doc/guix.texi

@@ -9083,6 +9083,16 @@ The crate importer also allows you to specify a version string:
 guix import crate constant-time-eq@@0.1.0
 @end example
 
+Additional options include:
+
+@table @code
+@item --recursive
+@itemx -r
+Traverse the dependency graph of the given upstream package recursively
+and generate package expressions for all those packages that are not yet
+in Guix.
+@end table
+
 @item opam
 @cindex OPAM
 @cindex OCaml

guix/scripts/import/crate.scm

@@ -28,6 +28,7 @@
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-37)
+  #:use-module (srfi srfi-41)
   #:use-module (ice-9 match)
   #:use-module (ice-9 format)
   #:export (guix-import-crate))
@@ -43,6 +44,9 @@
 (define (show-help)
   (display (G_ "Usage: guix import crate PACKAGE-NAME
 Import and convert the crate.io package for PACKAGE-NAME.\n"))
+  (display (G_ "
+  -r, --recursive        import packages recursively"))
+  (newline)
   (display (G_ "
   -h, --help             display this help and exit"))
   (display (G_ "
@@ -59,6 +63,9 @@ Import and convert the crate.io package for PACKAGE-NAME.\n"))
          (option '(#\V "version") #f #f
                  (lambda args
                    (show-version-and-exit "guix import crate")))
+         (option '(#\r "recursive") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'recursive #t result)))
          %standard-import-options))
 
 
@@ -88,13 +95,22 @@ Import and convert the crate.io package for PACKAGE-NAME.\n"))
        (define-values (name version)
          (package-name->name+version spec))
 
+       (if (assoc-ref opts 'recursive)
+           (map (match-lambda
+                  ((and ('package ('name name) . rest) pkg)
+                   `(define-public ,(string->symbol name)
+                      ,pkg))
+                  (_ #f))
+                (reverse
+                 (stream->list
+                  (crate-recursive-import name))))
            (let ((sexp (crate->guix-package name version)))
              (unless sexp
                (leave (G_ "failed to download meta-data for package '~a'~%")
                       (if version
                           (string-append name "@" version)
                           name)))
-         sexp))
+             sexp)))
       (()
        (leave (G_ "too few arguments~%")))
       ((many ...)