add `make-environment-variables'

Swap order of argument for `environment-variables-get'
and `environment-variables-set!', so that the environment
variables come first --- which follows the usual order.
This change means that the parameter isn't used to get
the default environment variables, but that seems ok; the
convenient interface is `getenv' and `putenv'.

On Windows, case-normalized environment variable names.

Also, change the implementation to use an immutable hash
internally.

collects/racket/private/misc.rkt

@@ -203,7 +203,8 @@
   (define (getenv s)
     (unless (string-environment-variable-name? s)
       (raise-argument-error 'getenv "string-environment-variable-name?" s))
-    (let ([v (environment-variables-get (string->bytes/locale s (char->integer #\?)))])
+    (let ([v (environment-variables-get (current-environment-variables)
+                                        (string->bytes/locale s (char->integer #\?)))])
       (and v
            (bytes->string/locale v #\?))))
 
@@ -213,9 +214,9 @@
     (unless (string-no-nuls? t)
       (raise-argument-error 'putenv "string-no-nuls?" 1 s t))
     (and
-     (environment-variables-set! (string->bytes/locale s (char->integer #\?))
+     (environment-variables-set! (current-environment-variables)
+                                 (string->bytes/locale s (char->integer #\?))
                                  (string->bytes/locale t (char->integer #\?))
-                                 (current-environment-variables)
                                  (lambda () #f))
      #t))
 

collects/scribblings/reference/envvars.scrbl

@@ -9,6 +9,12 @@ from byte strings to bytes strings. A Racket process's initial
 environment variables: accesses or changes to the set read or change
 operating-system environment variables for the Racket process.
 
+Since Windows environment variables are case-insensitive, and
+@tech{environment variable set}'s key byte strings on Windows are
+case-folded. More precisely, key byte strings are coerced to a UTF-8
+encoding of characters that are converted to lowercase via
+@racket[string-locale-downcase].
+
 The current @tech{environment variable set}, which is determined by
 the @racket[current-environment-variables] parameter, is propagated to
 a @tech{subprocess} when the @tech{subprocess} is created.
@@ -24,8 +30,7 @@ set}, @racket[#f] otherwise.}
 
 A @tech{parameter} that determines the @tech{environment variable set}
 that is propagated to a @tech{subprocess} and that is used as the
-default set for functions such as @racket[environment-variables-get] or
+default set for @racket[getenv] and @racket[putenv].}
-@racket[getenv].}
 
 
 @defproc[(bytes-environment-variable-name? [v any/c]) boolean?]{
@@ -37,9 +42,17 @@ contain no bytes with the value @racket[0] or @racket[61], where
 environment variable name also must have a non-zero length.}
 
 
-@defproc[(environment-variables-get [name bytes-environment-variable-name?]
+@defproc[(make-environment-variables [name bytes-environment-variable-name?]
-                                    [env environment-variables?
+                                     [val bytes-no-nuls?]
-                                         (current-environment-variables)])
+                                     ... ...)
+         environment-variables?]{
+
+Creates a fresh @tech{environment variable set} that is initialized
+with the given @racket[name] to @racket[val] mappings.}
+
+
+@defproc[(environment-variables-get [env environment-variables?]
+                                    [name bytes-environment-variable-name?])
          (or/c #f (and/c bytes-no-nuls? immutable?))]{
 
 Returns the mapping for @racket[name] in @racket[env], returning
@@ -47,14 +60,12 @@ Returns the mapping for @racket[name] in @racket[env], returning
 
 Normally, @racket[name] should be a byte-string encoding of a string
 using the default encoding of the current @tech{locale}. On Windows,
-@racket[name] is coerced to a UTF-8 encoding if @racket[env] is the
+@racket[name] is coerced to a UTF-8 encoding and case-normalized.}
-initial @tech{environment variable set} of the Racket process.}
 
 
-@defproc[(environment-variables-set! [name bytes-environment-variable-name?]
+@defproc[(environment-variables-set! [env environment-variables?]
+                                     [name bytes-environment-variable-name?]
                                      [maybe-bstr (or/c bytes-no-nuls? #f)]
-                                     [env environment-variables?
-                                          (current-environment-variables)]
                                      [fail (-> any)
                                            (lambda ()
                                              (raise (make-exn:fail ....)))])
@@ -68,8 +79,9 @@ for @racket[name] is removed.
 
 Normally, @racket[name] and @racket[maybe-bstr] should be a
 byte-string encoding of a string using the default encoding of the
-current @tech{locale}. On Windows, @racket[name] and
+current @tech{locale}. On Windows, @racket[name] is 
-@racket[maybe-bstr] are coerced to a UTF-8 encoding if @racket[env] is
+coerced to a UTF-8 encoding and case-normalized, and
+@racket[maybe-bstr] is coerced to a UTF-8 encoding if @racket[env] is
 the initial @tech{environment variable set} of the Racket process.
 
 On success, the result of @racket[environment-variables-set!] is

collects/tests/racket/file.rktl

@@ -1261,6 +1261,8 @@
 (test #t environment-variables? (current-environment-variables))
 (test #f environment-variables? 10)
 (test #t environment-variables? (environment-variables-copy (current-environment-variables)))
+(test #t environment-variables? (make-environment-variables))
+(test #t environment-variables? (make-environment-variables #"A" #"1"))
 (test #t list? (environment-variables-keys (current-environment-variables)))
 (test #t andmap bytes? (environment-variables-keys (current-environment-variables)))
 (test #t = 
@@ -1274,6 +1276,11 @@
 (test #f string-environment-variable-name? "x\0")
 (test (not (eq? 'windows (system-type))) string-environment-variable-name? "")
 
+(test #"1" environment-variables-get (make-environment-variables #"a" #"1" #"b" #"two") #"a")
+(test #"two" environment-variables-get (make-environment-variables #"a" #"1" #"b" #"two") #"b")
+(test #f environment-variables-get (make-environment-variables #"a" #"1" #"b" #"two") #"c")
+(test #f environment-variables-get (make-environment-variables) #"a")
+
 (define (env-var-tests)
   (define success-1? (putenv "APPLE" "AnApple"))
   (define success-2? (putenv "BANANA" "AnotherApple"))
@@ -1290,19 +1297,22 @@
   (test "AnotherApple" getenv "BANANA")
   (test #f getenv "AnUndefinedEnvironmentVariable")
 
-  (test #"AnApple" environment-variables-get #"APPLE")
+  (define env (current-environment-variables))
-  (err/rt-test (environment-variables-get #"=AP=PLE="))
+  (test #"AnApple" environment-variables-get env #"APPLE")
-  (test (void) environment-variables-set! #"APPLE" #"=x=")
+  (err/rt-test (environment-variables-get env #"=AP=PLE="))
-  (test #"=x=" environment-variables-get #"APPLE")
+  (test (void) environment-variables-set! env #"APPLE" #"=x=")
-  (test #"AnotherApple" environment-variables-get #"BANANA")
+  (test #"=x=" environment-variables-get env #"APPLE")
-  (test (void) environment-variables-set! #"BANANA" #f)
+  (test #"AnotherApple" environment-variables-get env #"BANANA")
-  (test #f environment-variables-get #"BANANA")
+  (test (void) environment-variables-set! env #"BANANA" #f)
+  (test #f environment-variables-get env #"BANANA")
   (test #f getenv "BANANA")
 
-  (test #"APPLE" car (member #"APPLE" (environment-variables-keys
+  (let ([apple (if (eq? 'windows (system-type))
-                                       (current-environment-variables))))
+                   #"apple"
-  (test #f member #"BANANA" (environment-variables-keys
+                   #"APPLE")])
-                             (current-environment-variables))))
+    (test apple car (member apple (environment-variables-keys env))))
+  (test #f member #"BANANA" (environment-variables-keys env))
+  (test #f member #"banana" (environment-variables-keys env)))
 
 (parameterize ([current-environment-variables
                 (environment-variables-copy

collects/tests/racket/subprocess.rktl

@@ -470,7 +470,7 @@
                  [current-environment-variables
                   (environment-variables-copy
                    (current-environment-variables))])
-    (environment-variables-set! #"Hola" #"hi, there")
+    (environment-variables-set! (current-environment-variables) #"Hola" #"hi, there")
     (system* self "-e" "(getenv \"Hola\")"))
   (test "\"hi, there\"\n" get-output-string out))
 

doc/release-notes/racket/HISTORY.txt

@@ -1,3 +1,6 @@
+Version 5.3.4.3
+Added make-environment-variables
+
 Version 5.3.4.2
 Added current-environment-variables, environment-variables-get,
  environment-variables-set!, environment-variables-keys,

src/get-libs.rkt

@@ -104,7 +104,8 @@
          ["libpangocairo-1.0-0.dll" 94625]
          ["libpangowin32-1.0-0.dll" 143647]
          ["libpangoft2-1.0-0.dll" 679322]]
-       (if (environment-variables-get #"PLT_WIN_GTK")
+       (if (environment-variables-get (current-environment-variables)
+                                      #"PLT_WIN_GTK")
            '(["libatk-1.0-0.dll" 153763]
              ["libgtk-win32-2.0-0.dll" 4740156]
              ["libgdk-win32-2.0-0.dll" 827670]
@@ -195,7 +196,8 @@
   (define-values (path-size/show)
     (lambda (path)
       (let-values ([(sz) (path-size path)])
-        (if (environment-variables-get #"PLT_SHOW_PATH_SIZES")
+        (if (environment-variables-get (current-environment-variables)
+                                       #"PLT_SHOW_PATH_SIZES")
             (printf "~s ~s\n" path sz)
             (void))
         sz)))

src/racket/src/schminc.h

@@ -14,7 +14,7 @@
 
 #define USE_COMPILED_STARTUP 1
 
-#define EXPECTED_PRIM_COUNT 1092
+#define EXPECTED_PRIM_COUNT 1093
 #define EXPECTED_UNSAFE_COUNT 100
 #define EXPECTED_FLFXNUM_COUNT 69
 #define EXPECTED_EXTFL_COUNT 45

src/racket/src/schpriv.h

@@ -4000,8 +4000,7 @@ void scheme_unused_intptr(intptr_t);
 
 intptr_t scheme_check_overflow(intptr_t n, intptr_t m, intptr_t a);
 
-Scheme_Object *scheme_make_environment_variables(Scheme_Hash_Table *ht);
+Scheme_Object *scheme_make_environment_variables(Scheme_Hash_Tree *ht);
-# define SCHEME_ENVVARS_TABLE(ev) ((Scheme_Hash_Table *)SCHEME_PTR_VAL(ev))
 void *scheme_environment_variables_to_block(Scheme_Object *env, int *_need_free);
 
 /*========================================================================*/

src/racket/src/schvers.h

@@ -13,12 +13,12 @@
    consistently.)
 */
 
-#define MZSCHEME_VERSION "5.3.4.2"
+#define MZSCHEME_VERSION "5.3.4.3"
 
 #define MZSCHEME_VERSION_X 5
 #define MZSCHEME_VERSION_Y 3
 #define MZSCHEME_VERSION_Z 4
-#define MZSCHEME_VERSION_W 2
+#define MZSCHEME_VERSION_W 3
 
 #define MZSCHEME_VERSION_MAJOR ((MZSCHEME_VERSION_X * 100) + MZSCHEME_VERSION_Y)
 #define MZSCHEME_VERSION_MINOR ((MZSCHEME_VERSION_Z * 1000) + MZSCHEME_VERSION_W)

src/racket/src/startup.inc

@@ -261,7 +261,8 @@
 "(if(and(relative-path? program)"
 "(let-values(((base name dir?)(split-path program)))"
 "(eq? base 'relative)))"
-" (let ((paths-str (environment-variables-get #\"PATH\"))"
+"(let((paths-str(environment-variables-get(current-environment-variables)"
+" #\"PATH\"))"
 "(win-add(lambda(s)(if(eq?(system-type) 'windows) "
 " (cons (bytes->path #\".\") s) "
 " s))))"
@@ -635,7 +636,8 @@
 "(cons-if(lambda(f r)(if f(cons f r) r))))"
 "(path-list-string->path-list"
 "(if user-too?"
-" (let ((c (environment-variables-get #\"PLTCOLLECTS\")))"
+"(let((c(environment-variables-get(current-environment-variables)"
+" #\"PLTCOLLECTS\")))"
 "(if c"
 "(bytes->string/locale c #\\?)"
 " \"\"))"

src/racket/src/startup.rktl

@@ -316,7 +316,8 @@
 	(if (and (relative-path? program)
 		 (let-values ([(base name dir?) (split-path program)])
 		   (eq? base 'relative)))
-	    (let ([paths-str (environment-variables-get #"PATH")]
+	    (let ([paths-str (environment-variables-get (current-environment-variables)
+                                                        #"PATH")]
 		  [win-add (lambda (s) (if (eq? (system-type) 'windows) 
 					   (cons (bytes->path #".") s) 
 					   s))])
@@ -731,7 +732,8 @@
 	    [cons-if (lambda (f r) (if f (cons f r) r))])
 	(path-list-string->path-list
 	 (if user-too?
-             (let ([c (environment-variables-get #"PLTCOLLECTS")])
+             (let ([c (environment-variables-get (current-environment-variables)
+                                                 #"PLTCOLLECTS")])
                (if c
                    (bytes->string/locale c #\?)
                    ""))

src/racket/src/string.c

@@ -306,6 +306,7 @@ static Scheme_Object *sch_getenv(int argc, Scheme_Object *argv[]);
 static Scheme_Object *sch_getenv_names(int argc, Scheme_Object *argv[]);
 static Scheme_Object *sch_putenv(int argc, Scheme_Object *argv[]);
 static Scheme_Object *env_copy(int argc, Scheme_Object *argv[]);
+static Scheme_Object *env_make(int argc, Scheme_Object *argv[]);
 static Scheme_Object *current_environment_variables(int argc, Scheme_Object *argv[]);
 static Scheme_Object *system_type(int argc, Scheme_Object *argv[]);
 static Scheme_Object *system_library_subpath(int argc, Scheme_Object *argv[]);
@@ -870,13 +871,13 @@ scheme_init_string (Scheme_Env *env)
   scheme_add_global_constant("environment-variables-get",
 			     scheme_make_immed_prim(sch_getenv,
 						    "environment-variables-get",
-						    1, 2),
+						    2, 2),
 			     env);
 
   scheme_add_global_constant("environment-variables-set!",
 			     scheme_make_prim_w_arity(sch_putenv,
                                                       "environment-variables-set!",
-                                                      2, 4),
+                                                      3, 4),
 			     env);
 
   scheme_add_global_constant("environment-variables-keys",
@@ -891,6 +892,12 @@ scheme_init_string (Scheme_Env *env)
 						    1, 1),
 			     env);
 
+  scheme_add_global_constant("make-environment-variables",
+			     scheme_make_immed_prim(env_make,
+						    "make-environment-variables",
+						    0, -1),
+			     env);
+
   /* Don't make these folding, since they're platform-specific: */
 
   scheme_add_global_constant("system-type",
@@ -2093,7 +2100,9 @@ extern char **environ;
 # define GET_ENVIRON_ARRAY environ
 #endif
 
-Scheme_Object *scheme_make_environment_variables(Scheme_Hash_Table *ht)
+#define SCHEME_ENVVARS_TABLE(ev) ((Scheme_Hash_Tree *)SCHEME_PTR_VAL(ev))
+
+Scheme_Object *scheme_make_environment_variables(Scheme_Hash_Tree *ht)
 {
   Scheme_Object *ev;
 
@@ -2238,25 +2247,32 @@ int byte_string_ok_name(Scheme_Object *o)
   return 1;
 }
 
+static Scheme_Object *normalize_env_case(Scheme_Object *bs)
+{
+#ifdef DOS_FILE_SYSTEM
+  bs = scheme_byte_string_to_char_string(bs);
+  bs = string_locale_downcase(1, &bs);
+  bs = scheme_char_string_to_byte_string(bs);
+#endif
+  return bs;
+}
+
 static Scheme_Object *sch_getenv(int argc, Scheme_Object *argv[])
 {
   char *name;
   char *value;
   Scheme_Object *bs, *ev, *val;
-  Scheme_Hash_Table *ht;
+  Scheme_Hash_Tree *ht;
 
-  bs = argv[0];
+  if (!SAME_TYPE(SCHEME_TYPE(argv[0]), scheme_environment_variables_type))
+    scheme_wrong_contract("environment-variables-get", "environment-variables?", 0, argc, argv);
+
+  bs = argv[1];
   if (!SCHEME_BYTE_STRINGP(bs)
       || !byte_string_ok_name(bs))
-    scheme_wrong_contract("environment-variables-get", "bytes-environment-variable-name?", 0, argc, argv);
+    scheme_wrong_contract("environment-variables-get", "bytes-environment-variable-name?", 1, argc, argv);
-  if ((argc > 1)
-      && !SAME_TYPE(SCHEME_TYPE(argv[1]), scheme_environment_variables_type))
-    scheme_wrong_contract("environment-variables-get", "environment-variables?", 1, argc, argv);
 
-  if (argc > 1)
+  ev = argv[0];
-    ev = argv[1];
-  else
-    ev = scheme_get_param(scheme_current_config(), MZCONFIG_CURRENT_ENV_VARS);
   ht = SCHEME_ENVVARS_TABLE(ev);
 
   if (!ht) {
@@ -2270,7 +2286,8 @@ static Scheme_Object *sch_getenv(int argc, Scheme_Object *argv[])
 
     return value ? scheme_make_byte_string(value) : scheme_false;
   } else {
-    val = scheme_hash_get_atomic(ht, bs);
+    bs = normalize_env_case(bs);
+    val = scheme_hash_tree_get(ht, bs);
     return val ? val : scheme_false;
   }
 }
@@ -2320,41 +2337,43 @@ static int sch_unix_putenv(const char *var, const char *val, const intptr_t varl
 static Scheme_Object *sch_putenv(int argc, Scheme_Object *argv[])
 {
   Scheme_Object *varbs, *valbs, *ev;
-  Scheme_Hash_Table *ht;
+  Scheme_Hash_Tree *ht;
   char *var;
   char *val;
   int rc = 0, errid = 0;
 
-  varbs = argv[0];
+  if (!SAME_TYPE(SCHEME_TYPE(argv[0]), scheme_environment_variables_type))
+    scheme_wrong_contract("environment-variables-set!", "environment-variables?", 0, argc, argv);
+  
+  varbs = argv[1];
   if (!SCHEME_BYTE_STRINGP(varbs)
       || !byte_string_ok_name(varbs))
-    scheme_wrong_contract("environment-variables-set!", "bytes-environment-variable-name?", 0, argc, argv);
+    scheme_wrong_contract("environment-variables-set!", "bytes-environment-variable-name?", 1, argc, argv);
-  valbs = argv[1];
+
+  valbs = argv[2];
   if (!SCHEME_FALSEP(valbs)
       && (!SCHEME_BYTE_STRINGP(valbs)
           || scheme_byte_string_has_null(valbs)))
-    scheme_wrong_contract("environment-variables-set!", "(or/c bytes-no-nuls? #f)", 1, argc, argv);
+    scheme_wrong_contract("environment-variables-set!", "(or/c bytes-no-nuls? #f)", 2, argc, argv);
-  if ((argc > 2)
-      && !SAME_TYPE(SCHEME_TYPE(argv[2]), scheme_environment_variables_type))
-    scheme_wrong_contract("environment-variables-set!", "environment-variables?", 1, argc, argv);
   if (argc > 3)
     scheme_check_proc_arity("environment-variables-set!", 0, 3, argc, argv);
 
-  if (argc > 2)
+  ev = argv[0];
-    ev = argv[2];
-  else
-    ev = scheme_get_param(scheme_current_config(), MZCONFIG_CURRENT_ENV_VARS);
   ht = SCHEME_ENVVARS_TABLE(ev);
 
   if (ht) {
+    varbs = normalize_env_case(varbs);
+
     if (SCHEME_FALSEP(valbs)) {
-      scheme_hash_set_atomic(ht, varbs, NULL);
+      ht = scheme_hash_tree_set(ht, varbs, NULL);
     } else {
       varbs = byte_string_to_immutable(1, &varbs);
       valbs = byte_string_to_immutable(1, &valbs);
-      scheme_hash_set_atomic(ht, varbs, valbs);
+      ht = scheme_hash_tree_set(ht, varbs, valbs);
     }
 
+    SCHEME_PTR_VAL(ev) = (Scheme_Object *)ht;
+
     return scheme_void;
   } else {
     var = SCHEME_BYTE_STR_VAL(varbs);
@@ -2391,22 +2410,22 @@ static Scheme_Object *sch_putenv(int argc, Scheme_Object *argv[])
 
 static Scheme_Object *env_copy(int argc, Scheme_Object *argv[])
 {
-  Scheme_Hash_Table *ht;
+  Scheme_Hash_Tree *ht;
 
   if (!SAME_TYPE(SCHEME_TYPE(argv[0]), scheme_environment_variables_type))
     scheme_wrong_contract("environment-variables-copy", "environment-variables?", 0, argc, argv);
 
   ht = SCHEME_ENVVARS_TABLE(argv[0]);
   if (ht)
-    return scheme_make_environment_variables(scheme_clone_hash_table(ht));
+    return scheme_make_environment_variables(ht);
   
   /* copy system environment variables into a hash table: */
-  ht = scheme_make_hash_table_equal();
+  ht = scheme_make_hash_tree(1);
 
 #ifdef DOS_FILE_SYSTEM
   {
     char *p;
-    wchar_t *e;
+    GC_CAN_IGNORE wchar_t *e;
     int i, start, j;
     Scheme_Object *var, *val;
 
@@ -2414,16 +2433,15 @@ static Scheme_Object *env_copy(int argc, Scheme_Object *argv[])
 
     for (i = 0; e[i]; ) {
       start = i;
-      while (e[i]) {
+      while (e[i]) { i++; }
-        i++;
-      }
       p = NARROW_PATH(e XFORM_OK_PLUS start);
       for (j = 0; p[j] && p[j] != '='; j++) {
       }
-      if (p[j]) {
+      if (j && p[j]) {
         var = scheme_make_immutable_sized_byte_string(p, j, 1);
         val = scheme_make_immutable_sized_byte_string(p XFORM_OK_PLUS j + 1, -1, 1);
-        scheme_hash_set(ht, var, val);
+        var = normalize_env_case(var);
+        ht = scheme_hash_tree_set(ht, var, val);
       }
       i++;
     }
@@ -2445,7 +2463,7 @@ static Scheme_Object *env_copy(int argc, Scheme_Object *argv[])
       if (p[j]) {
         var = scheme_make_immutable_sized_byte_string(p, j, 1);
         val = scheme_make_immutable_sized_byte_string(p XFORM_OK_PLUS j + 1, -1, 1);
-        scheme_hash_set(ht, var, val);
+        ht = scheme_hash_tree_set(ht, var, val);
       }
     }
   }
@@ -2454,10 +2472,48 @@ static Scheme_Object *env_copy(int argc, Scheme_Object *argv[])
   return scheme_make_environment_variables(ht);
 }
 
+static Scheme_Object *env_make(int argc, Scheme_Object *argv[])
+{
+  Scheme_Hash_Tree *ht;
+  Scheme_Object *varbs, *valbs;
+  int i;
+
+  ht = scheme_make_hash_tree(1);
+
+  for (i = 0; i < argc; i += 2) {
+    varbs = argv[i];
+    if (!SCHEME_BYTE_STRINGP(varbs)
+        || !byte_string_ok_name(varbs))
+      scheme_wrong_contract("make-environment-variables", "bytes-environment-variable-name?", i, argc, argv);
+
+    if (i+1 >= argc) {
+      scheme_contract_error("make-environment-variables",
+                            "key does not have a value (i.e., an odd number of arguments were provided)",
+                            "key", 1, argv[i],
+                            NULL);
+      return NULL;
+    }
+
+    valbs = argv[i+1];
+    if (!SCHEME_FALSEP(valbs)
+        && (!SCHEME_BYTE_STRINGP(valbs)
+            || scheme_byte_string_has_null(valbs)))
+      scheme_wrong_contract("make-environment-variables", "(or/c bytes-no-nuls? #f)", i+1, argc, argv);
+
+    varbs = normalize_env_case(varbs);
+
+    varbs = byte_string_to_immutable(1, &varbs);
+    valbs = byte_string_to_immutable(1, &valbs);
+    ht = scheme_hash_tree_set(ht, varbs, valbs);
+  }
+
+  return scheme_make_environment_variables(ht);
+}
+
 static Scheme_Object *sch_getenv_names(int argc, Scheme_Object *argv[])
 {
-  Scheme_Object *ev, *r = scheme_null;
+  Scheme_Object *ev, *r = scheme_null, *key, *val;
-  Scheme_Hash_Table *ht;
+  Scheme_Hash_Tree *ht;
   int i;
 
   ev = argv[0];
@@ -2470,10 +2526,9 @@ static Scheme_Object *sch_getenv_names(int argc, Scheme_Object *argv[])
     ht = SCHEME_ENVVARS_TABLE(ev);
   }
 
-  for (i = ht->size; i--; ) {
+  for (i = scheme_hash_tree_next(ht, -1); i != -1; i = scheme_hash_tree_next(ht, i)) {
-    if (ht->vals[i]) {
+    scheme_hash_tree_index(ht, i, &key, &val);
-      r = scheme_make_pair(ht->keys[i], r);
+    r = scheme_make_pair(key, r);
-    }
   }
 
   return r;
@@ -2490,7 +2545,8 @@ static int wc_strlen(const wchar_t *ws)
 
 void *scheme_environment_variables_to_block(Scheme_Object *ev, int *_need_free)
 {
-  Scheme_Hash_Table *ht;
+  Scheme_Hash_Tree *ht;
+  Scheme_Object *key, *val;
   
   ht = SCHEME_ENVVARS_TABLE(ev);
   if (!ht) {
@@ -2510,32 +2566,30 @@ void *scheme_environment_variables_to_block(Scheme_Object *ev, int *_need_free)
     int len = 0, slen;
     GC_CAN_IGNORE wchar_t *r, *s;
 
-    for (i = ht->size; i--; ) {
+    for (i = scheme_hash_tree_next(ht, -1); i != -1; i = scheme_hash_tree_next(ht, i)) {
-      if (ht->vals[i]) {
+      scheme_hash_tree_index(ht, i, &key, &val);
-        len += wc_strlen(WIDE_PATH(SCHEME_BYTE_STR_VAL(ht->keys[i])));
+      len += wc_strlen(WIDE_PATH(SCHEME_BYTE_STR_VAL(key)));
-        len += wc_strlen(WIDE_PATH(SCHEME_BYTE_STR_VAL(ht->vals[i])));
+      len += wc_strlen(WIDE_PATH(SCHEME_BYTE_STR_VAL(val)));
       len += 2;
     }
-    }
 
     r = (wchar_t *)malloc((len + 1) * sizeof(wchar_t));
 
     len = 0;
 
-    for (i = ht->size; i--; ) {
+    for (i = scheme_hash_tree_next(ht, -1); i != -1; i = scheme_hash_tree_next(ht, i)) {
-      if (ht->vals[i]) {
+      scheme_hash_tree_index(ht, i, &key, &val);
-        s = WIDE_PATH(SCHEME_BYTE_STR_VAL(ht->keys[i]));
+      s = WIDE_PATH(SCHEME_BYTE_STR_VAL(key));
       slen = wc_strlen(s);
       memcpy(r XFORM_OK_PLUS len, s, slen * sizeof(wchar_t));
       len += slen;
       r[len++] = '=';
-        s = WIDE_PATH(SCHEME_BYTE_STR_VAL(ht->vals[i]));
+      s = WIDE_PATH(SCHEME_BYTE_STR_VAL(val));
       slen = wc_strlen(s);
       memcpy(r XFORM_OK_PLUS len, s, slen * sizeof(wchar_t));
       len += slen;
       r[len++] = 0;
     }
-    }
     r[len] = 0;
 
     return r;
@@ -2545,29 +2599,29 @@ void *scheme_environment_variables_to_block(Scheme_Object *ev, int *_need_free)
     GC_CAN_IGNORE char **r, *s;
     intptr_t i, len = 0, slen, c;
 
-    for (i = ht->size; i--; ) {
+    for (i = scheme_hash_tree_next(ht, -1); i != -1; i = scheme_hash_tree_next(ht, i)) {
-      if (ht->vals[i]) {
+      scheme_hash_tree_index(ht, i, &key, &val);
-        len += SCHEME_BYTE_STRLEN_VAL(ht->keys[i]);
+      len += SCHEME_BYTE_STRLEN_VAL(key);
-        len += SCHEME_BYTE_STRLEN_VAL(ht->vals[i]);
+      len += SCHEME_BYTE_STRLEN_VAL(val);
       len += 2;
     }
-    }
 
     r = (char **)malloc((ht->count+1) * sizeof(char*) + len);
     s = (char *)(r + (ht->count+1));
-    for (i = ht->size, c = 0; i--; ) {
+    c = 0;
-      if (ht->vals[i]) {
+    for (i = scheme_hash_tree_next(ht, -1); i != -1; i = scheme_hash_tree_next(ht, i)) {
+      scheme_hash_tree_index(ht, i, &key, &val);
       r[c++] = s;
-        slen = SCHEME_BYTE_STRLEN_VAL(ht->keys[i]);
+      slen = SCHEME_BYTE_STRLEN_VAL(key);
-        memcpy(s, SCHEME_BYTE_STR_VAL(ht->keys[i]), slen);
+      memcpy(s, SCHEME_BYTE_STR_VAL(key), slen);
       s[slen] = '=';
       s = s XFORM_OK_PLUS (slen + 1);
-        slen = SCHEME_BYTE_STRLEN_VAL(ht->vals[i]);
+      slen = SCHEME_BYTE_STRLEN_VAL(val);
-        memcpy(s, SCHEME_BYTE_STR_VAL(ht->vals[i]), slen);
+      memcpy(s, SCHEME_BYTE_STR_VAL(val), slen);
       s[slen] = 0;
       s = s XFORM_OK_PLUS (slen + 1);
     }
-    }
+    r[c] = NULL;
 
     return r;
   }