ccwl: Implement js-expression.

js-expression corresponds to ExpressionTool in the CWL specification.

* ccwl/ccwl.scm (<js-expression>): New type.
(js-expression): New macro.
(function-inputs, function-outputs, function-object): Support
<js-expression> objects.
(function-input-keys): Mention <js-expression> objects in docstring.
* ccwl/cwl.scm (function->cwl, workflow->cwl-scm): Support
<js-expression> objects.
(command->cwl-scm): Move staging requirements handling to ...
(staging-requirements): ... this new function.
(js-expression->cwl, js-expression->cwl-scm): New functions.
* ccwl/graphviz.scm (function->dot): Support <js-expression> objects.
(command->graph): Abstract to ...
(single-node-workflow->graph): ... this new function.
(js-expression->dot, js-expression->graph): New functions.
* scripts/ccwl (main): Support <js-expression> objects.
* doc/ccwl.skb (Cookbook){Javascript expressions via ExpressionTool}:
New section.
* doc/js-expression-iota.scm: New file.

1 files changed, 2 insertions, 1 deletions

diff --git a/scripts/ccwl b/scripts/ccwl
index 43cf224..984d22a 100755
--- a/scripts/ccwl
+++ b/scripts/ccwl
@@ -123,10 +123,11 @@ Compile SOURCE-FILE.
                 (let ((result (load (canonicalize-path (assq-ref args 'source-file))
                                       read-syntax)))
                   (if (or (command? result)
+                          (js-expression? result)
                           (workflow? result))
                       result
                       (raise-exception
-                       (condition (formatted-message "Last expression in file ~a returns neither workflow nor command"
+                       (condition (formatted-message "Last expression in file ~a returns none of workflow, command or js-expression"
                                                      (assq-ref args 'source-file)))))))
               (current-output-port)))))
         ((program args ...)