Fix seven more JVM divergences (rewrite-clj full suite)

Running the whole rewrite-clj test suite (159 tests) surfaced seven more bugs;
with these it passes 3377/0/0. Each is a general jolt/JVM divergence:

- *out* was pinned to the startup stdout port, so (.write *out* …) escaped a
  with-out-str capture (z/print writes via *out*). It now resolves the live
  current-output-port, like print/__write, so a redirect is seen.
- nth / assoc past the end of a vector or seq threw a bare Chez error (class
  :object). Throw IndexOutOfBoundsException, matching the JVM.
- A number's .toString(radix) ignored the base. Render in the base, lowercase
  (rewrite-clj rebuilds 0xff / 0377 / 2r1001 through it).
- A required namespace's own :as aliases leaked into its requirer: the loaded ns
  form compiles while (chez-current-ns) is still the requirer, so ce-scan-requires!
  registered the loaded ns's aliases under the wrong ns and clobbered a same-named
  alias there. Register an (ns NAME …) form's aliases under NAME.
- A quoted collection dropped its metadata; now it keeps USER metadata (drops the
  reader's :line/:column/:file), like a Clojure quoted constant.
- enumeration-seq only did (seq e); it now drives a java.util.Enumeration through
  hasMoreElements/nextElement, and StringTokenizer implements them.

Regressions: corpus rows (with-out-str/*out*, nth/assoc bounds, toString radix,
quote metadata, enumeration-seq) certified against JVM; a smoke fixture for the
alias leak (a required ns's alias must not leak). tools.reader + rewrite-clj added
to docs/libraries.md. make test green.

host/chez/collections.ss

@@ -130,7 +130,7 @@
                     (vec-set (pvec-tail p) (fxand i pv-mask) x) #f)
            (mk-pvec cnt (pvec-shift p)
                     (pv-assoc-trie (pvec-shift p) (pvec-root p) i x) (pvec-tail p) #f)))
-      (else (error 'assoc "vector index out of bounds")))))
+      (else (jolt-throw (jolt-host-throwable "java.lang.IndexOutOfBoundsException" "vector index out of bounds"))))))
 (define (pvec-peek p)
   (let ((n (pvec-cnt p))) (if (fx=? n 0) jolt-nil (pvec-nth-d p (fx- n 1) jolt-nil))))
 ;; pop the last trie chunk back into the tail; #f means the subtree emptied.
@@ -449,9 +449,9 @@
      (let ((i (->idx i)))
        (cond ((pvec? coll) (let ((v (pvec-v coll)))
                              (if (and (fx>=? i 0) (fx<? i (vector-length v))) (vector-ref v i)
-                                 (error 'nth "index out of bounds"))))
+                                 (jolt-throw (jolt-host-throwable "java.lang.IndexOutOfBoundsException" "index out of bounds")))))
              ((string? coll) (if (and (fx>=? i 0) (fx<? i (string-length coll))) (string-ref coll i)
-                                 (error 'nth "index out of bounds")))
+                                 (jolt-throw (jolt-host-throwable "java.lang.IndexOutOfBoundsException" "index out of bounds"))))
              ((or (cseq? coll) (empty-list-t? coll)) (seq-nth coll i #f jolt-nil))
              ((rec-coll-method coll "nth") => (lambda (m) (jolt-invoke m coll i)))
              (else (error 'nth "unsupported collection")))))

host/chez/compile-eval.ss

@@ -111,6 +111,16 @@
 (let ((scv (var-deref "jolt.backend-scheme" "set-var-cache!")))
   (when (procedure? scv) (scv #t)))
 
+;; (with-meta sym m) -> sym, else x — an (ns ^:no-doc name …) yields the name with
+;; reader metadata as a with-meta form; strip it to read the bare ns symbol.
+(define (ce-unwrap-meta x)
+  (if (and (cseq? x) (cseq-list? x))
+      (let ((items (seq->list x)))
+        (if (and (pair? items) (symbol-t? (car items))
+                 (string=? (symbol-t-name (car items)) "with-meta") (pair? (cdr items)))
+            (cadr items) x))
+      x))
+
 ;; (quote X) -> X, else x — unwraps a quoted require spec.
 (define (ce-unquote x)
   (if (and (cseq? x) (cseq-list? x))
@@ -135,14 +145,22 @@
             ;; (require spec...) / (use spec...) — specs are quoted
             ((and hn (or (string=? hn "require") (string=? hn "use")))
              (for-each (lambda (a) (chez-register-spec! ns (ce-unquote a))) (cdr items)))
-            ;; (ns name (:require [a :as x]) ...) — clause specs are literal
+            ;; (ns name (:require [a :as x]) ...) — clause specs are literal. Register
+            ;; the aliases under NAME (the ns being defined), not the passed `ns`:
+            ;; when a file is loaded its ns form compiles while (chez-current-ns) is
+            ;; still the requiring ns, so using `ns` would leak the loaded ns's
+            ;; aliases into its requirer and clobber a same-named alias there
+            ;; (rewrite-clj.zip.base's [node.protocols :as node] over the caller's node).
             ((and hn (string=? hn "ns"))
-             (for-each (lambda (clause)
-                         (when (and (cseq? clause) (cseq-list? clause))
-                           (let ((cl (seq->list clause)))
-                             (when (ce-clause-require? cl)
-                               (for-each (lambda (spec) (chez-register-spec! ns spec)) (cdr cl))))))
-                       (if (pair? (cdr items)) (cddr items) '())))
+             (let ((ns-name (if (and (pair? (cdr items)) (symbol-t? (ce-unwrap-meta (cadr items))))
+                                (symbol-t-name (ce-unwrap-meta (cadr items)))
+                                ns)))
+               (for-each (lambda (clause)
+                           (when (and (cseq? clause) (cseq-list? clause))
+                             (let ((cl (seq->list clause)))
+                               (when (ce-clause-require? cl)
+                                 (for-each (lambda (spec) (chez-register-spec! ns-name spec)) (cdr cl))))))
+                         (if (pair? (cdr items)) (cddr items) '()))))
             (else (for-each (lambda (x) (ce-scan-requires! x ns)) items))))))))
 
 ;; Already-read FORM -> Scheme source string (analyze -> emit on Chez).

host/chez/java/host-static-classes.ss

@@ -176,14 +176,26 @@
 ;; push to the port (so (.write *out* s) and (binding [*out* *err*] …) work);
 ;; it isn't a buffer, so toString is empty. Lets libraries that touch *out*/*err*
 ;; (tools.logging, selmer) compile and run.
+;; *out*/*err* resolve their port LIVE — 'out -> (current-output-port), 'err ->
+;; (current-error-port) — so a (.write *out* …) / (.flush *out*) follows a
+;; with-out-str redirect (with-output-to-string rebinds current-output-port) the
+;; same way print/__write do. Storing the startup port instead pinned *out* to the
+;; real stdout, so rewrite-clj's (z/print) — which writes via *out* — escaped the
+;; capture. A stored port object (should any other code make a port-writer) is used
+;; as-is.
+(define (port-writer-port self)
+  (let ((p (vector-ref (jhost-state self) 0)))
+    (cond ((eq? p 'out) (current-output-port))
+          ((eq? p 'err) (current-error-port))
+          (else p))))
 (register-host-methods! "port-writer"
-  (list (cons "write" (lambda (self x) (display (writer-piece x) (vector-ref (jhost-state self) 0)) jolt-nil))
-        (cons "append" (lambda (self x . rest) (display (append-text x rest) (vector-ref (jhost-state self) 0)) self))
-        (cons "flush" (lambda (self) (flush-output-port (vector-ref (jhost-state self) 0)) jolt-nil))
+  (list (cons "write" (lambda (self x) (display (writer-piece x) (port-writer-port self)) jolt-nil))
+        (cons "append" (lambda (self x . rest) (display (append-text x rest) (port-writer-port self)) self))
+        (cons "flush" (lambda (self) (flush-output-port (port-writer-port self)) jolt-nil))
         (cons "close" (lambda (self) jolt-nil))
         (cons "toString" (lambda (self) ""))))
-(def-var! "clojure.core" "*out*" (make-jhost "port-writer" (vector (current-output-port))))
-(def-var! "clojure.core" "*err*" (make-jhost "port-writer" (vector (current-error-port))))
+(def-var! "clojure.core" "*out*" (make-jhost "port-writer" (vector 'out)))
+(def-var! "clojure.core" "*err*" (make-jhost "port-writer" (vector 'err)))
 
 ;; PrintWriter — a thin wrapper over a target writer. write/append/print forward
 ;; the rendered text to the target. clojure.data.json's pretty printer builds
@@ -443,7 +455,15 @@
                             (let ((toks (vector-ref (jhost-state self) 0)) (p (vector-ref (jhost-state self) 1)))
                               (if (< p (length toks))
                                   (begin (vector-set! (jhost-state self) 1 (+ p 1)) (list-ref toks p))
-                                  (error #f "NoSuchElementException")))))))
+                                  (error #f "NoSuchElementException")))))
+        ;; StringTokenizer implements java.util.Enumeration — enumeration-seq drives
+        ;; it through these, so alias them onto the token methods.
+        (cons "hasMoreElements" (lambda (self) (< (vector-ref (jhost-state self) 1) (length (vector-ref (jhost-state self) 0)))))
+        (cons "nextElement" (lambda (self)
+                              (let ((toks (vector-ref (jhost-state self) 0)) (p (vector-ref (jhost-state self) 1)))
+                                (if (< p (length toks))
+                                    (begin (vector-set! (jhost-state self) 1 (+ p 1)) (list-ref toks p))
+                                    (error #f "NoSuchElementException")))))))
 
 ;; ---- String / BigInteger / MapEntry constructors ----------------------------
 ;; (String. bytes [charset]) decodes bytes (a bytevector OR a jolt byte-array)

host/chez/java/host-static.ss

@@ -117,7 +117,12 @@
     ((string=? method "longValue") (->num (jnum->exact n)))
     ((string=? method "doubleValue") (->num n))
     ((string=? method "floatValue") (->num n))
-    ((string=? method "toString") (jolt-num->string n))
+    ;; .toString(radix) — BigInteger/Integer render in a base, lowercase like the
+    ;; JVM (rewrite-clj's integer node reconstructs 0xff / 0377 / 2r1001 this way).
+    ((string=? method "toString")
+     (if (pair? args)
+         (string-downcase (number->string (jnum->exact n) (jnum->exact (car args))))
+         (jolt-num->string n)))
     ((string=? method "hashCode") (->num (jnum->exact n)))
     ;; Double/Float .isNaN / .isInfinite (a non-flonum is neither).
     ((string=? method "isNaN") (and (flonum? n) (not (= n n))))

host/chez/seq.ss

@@ -152,9 +152,9 @@
                            (if (jolt-nil? s) last (loop (jolt-seq (seq-more s)) (seq-first s)))))
 ;; nth over a seq (walks; forces lazily). default? selects the 3-arg behavior.
 (define (seq-nth coll i default? d)
-  (if (fx<? i 0) (if default? d (error 'nth "index out of bounds"))
+  (if (fx<? i 0) (if default? d (jolt-throw (jolt-host-throwable "java.lang.IndexOutOfBoundsException" "index out of bounds")))
       (let loop ((s (jolt-seq coll)) (i i))
-        (cond ((jolt-nil? s) (if default? d (error 'nth "index out of bounds")))
+        (cond ((jolt-nil? s) (if default? d (jolt-throw (jolt-host-throwable "java.lang.IndexOutOfBoundsException" "index out of bounds"))))
               ((fx=? i 0) (seq-first s))
               (else (loop (jolt-seq (seq-more s)) (fx- i 1)))))))
 

host/chez/smoke.sh

@@ -93,6 +93,17 @@ else
   fails=$((fails + 1))
 fi
 
+# A required namespace's own :as aliases must not leak into the requirer: fix.main
+# aliases clojure.string as ss and requires fix.lib (which aliases clojure.set as
+# ss); (ss/upper-case "hi") in main must stay clojure.string -> "HI #{1 2}".
+al_out="$(JOLT_PWD="$root/test/chez/alias-leak-app" bin/joltc run -m fix.main 2>/dev/null | tail -1)"
+if [ "$al_out" = "HI #{1 2}" ]; then
+  pass=$((pass + 1))
+else
+  echo "  FAIL: a loaded ns's alias leaked into its requirer — got \`$al_out\`, want \`HI #{1 2}\`"
+  fails=$((fails + 1))
+fi
+
 # Unit-checks the REPL read-until-complete predicate over balanced/unbalanced,
 # string, comment and regex-literal inputs. A multi-form `joltc run` so jolt.main
 # is loaded and its private var resolves; the file self-checks and prints a sentinel.