Standalone runner implementation in racket

Better name TBD. This is the file that is compiled to produce the
self-contained executable that can evaluate and hopefully compile unison
code, without the user having to separately install racket.

scheme-libs/racket/runner.rkt

@@ -0,0 +1,88 @@
+#!racket/base
+
+(require
+  (except-in racket false true unit any)
+  compiler/embed
+  unison/boot
+  unison/data
+  unison/data-info
+  unison/chunked-seq
+  unison/primops
+  unison/primops-generated
+  unison/builtin-generated)
+
+(define (grab-bytes)
+  (let* ([size-bytes (read-bytes 4)]
+         [size (integer-bytes->integer size-bytes #f #t 0 4)])
+    (read-bytes size)))
+
+(define (decode-input)
+  (let ([bs (grab-bytes)])
+    (match (builtin-Value.deserialize (bytes->chunked-bytes bs))
+      [(unison-data _ t (list q))
+       (= t unison-either-right:tag)
+       (apply
+         values
+         (unison-tuple->list (reify-value (unison-quote-val q))))]
+      [else
+        (raise "unexpected input")])))
+
+(define (build-main-module main-def)
+  `(module unison-main racket/base
+     (require
+       unison/boot)
+
+     (provide main)
+
+     (define (main)
+       (handle ['ref-4n0fgs00] top-exn-handler
+               (,(termlink->name main-def))))))
+
+(define (do-evaluate)
+  (let-values ([(code main-ref) (decode-input)])
+    (add-runtime-code 'unison-main code)
+    (handle ['ref-4n0fgs00] top-exn-handler
+            ((termlink->proc main-ref))
+            (data 'unit 0))))
+
+; stub implementation
+(define (do-compile output) (void))
+  ; (let-values ([(code main-ref) (decode-input)])
+  ;   (create-embedding-executable
+  ;     output
+  ;     #:modules '((#f unison-main))
+  ;     #:literal-expression '(begin (require unison-main) (main)))))
+
+(define runtime-namespace
+  (let ([ns (variable-reference->namespace (#%variable-reference))])
+    (namespace-require ''#%kernel ns)
+    ns))
+
+(define (chunked-list->list cl)
+  (vector->list (chunked-list->vector cl)))
+
+(define (list->chunked-list l)
+  (vector->chunked-list (list->vector l)))
+
+(define (join ls)
+  (cond
+    [(null? ls) '()]
+    [else (append (car ls) (join (cdr ls)))]))
+
+(define compile (make-parameter #f))
+
+(define (handle-command-line)
+  (command-line
+    #:program "runner"
+    #:once-any
+    [("-o" "--output")
+       file
+       "compile to <file>"
+       (compile file)]
+    #:args ()
+    (compile)))
+
+(let ([out (handle-command-line)])
+  (if out
+    (do-compile out)
+    (do-evaluate)))