Host completeness for the ring stack (ring-app)

Gaps surfaced loading ring-core / hiccup / config / tools.logging on Chez:

- clojure.java.io/resource — resolve a named resource against the loader's
  source roots (no classpath), returning a slurp-able File.
- (Object.) constructor — a fresh distinct value (lock / unique sentinel).
- *out* / *err* as dynamic vars over a port-writer, so (binding [*out* *err*] …)
  and #'*out* compile and run (tools.logging, selmer).
- :refer :all now registers a refer-all relation, so an unqualified var from a
  (require '[ns :refer :all]) resolves at compile time — including #'var.
- java.lang.Character interop ((.toString \+) etc.).
- StringReader accepts a char[] ((StringReader. (char-array s))), not just a
  String.
- the \p{L} translation stops just below the UTF-16 surrogate gap (\x{D7FF})
  instead of \x{10FFFF} — a range across the surrogates made irregex's char-set
  construction call integer->char on a surrogate and crash.

host/chez/io.ss

@@ -263,4 +263,15 @@
 (def-var! "clojure.java.io" "writer" jolt-io-writer)
 (def-var! "clojure.java.io" "input-stream" jolt-io-reader)
 (def-var! "clojure.java.io" "output-stream" jolt-io-writer)
+;; resource: jolt has no classpath, so a named resource is resolved against the
+;; loader's source roots (a project's :paths, e.g. "resources"). Returns a File
+;; (slurp/reader-able) for the first match, else nil. get-source-roots is the
+;; loader's accessor (loader.ss), resolved at call time — the runtime CLI loads it.
+(define (jolt-io-resource name)
+  (let ((nm (jolt-str-render-one name)))
+    (let loop ((roots (get-source-roots)))
+      (cond ((null? roots) jolt-nil)
+            ((file-exists? (string-append (car roots) "/" nm)) (make-jfile (string-append (car roots) "/" nm)))
+            (else (loop (cdr roots)))))))
+(def-var! "clojure.java.io" "resource" jolt-io-resource)
 (def-var! "clojure.java.io" "as-url" (lambda (x) (if (and (jhost? x) (string=? (jhost-tag x) "url")) x (make-url (jolt-str-render-one x)))))