diff --git a/contrib/20.r7rs/src/file.c b/contrib/20.r7rs/src/file.c
index dd94803c..9aeae3d4 100644
--- a/contrib/20.r7rs/src/file.c
+++ b/contrib/20.r7rs/src/file.c
@@ -11,7 +11,7 @@ file_error(pic_state *pic, const char *msg)
 {
   struct pic_error *e;
 
-  e = pic_make_error(pic, pic_intern_cstr(pic, "file"), msg, pic_nil_value());
+  e = pic_make_error(pic, pic_intern(pic, "file"), msg, pic_nil_value());
 
   pic_raise(pic, pic_obj_value(e));
 }
diff --git a/contrib/20.r7rs/src/load.c b/contrib/20.r7rs/src/load.c
index f0d65b6e..15cc6cae 100644
--- a/contrib/20.r7rs/src/load.c
+++ b/contrib/20.r7rs/src/load.c
@@ -4,27 +4,20 @@
 
 #include "picrin.h"
 
-void
-pic_load(pic_state *pic, const char *filename)
-{
-  struct pic_port *port;
-
-  port = pic_open_file(pic, filename, PIC_PORT_IN | PIC_PORT_TEXT);
-
-  pic_load_port(pic, port);
-
-  pic_close_port(pic, port);
-}
-
 static pic_value
 pic_load_load(pic_state *pic)
 {
   pic_value envid;
   char *fn;
+  struct pic_port *port;
 
   pic_get_args(pic, "z|o", &fn, &envid);
 
-  pic_load(pic, fn);
+  port = pic_open_file(pic, fn, PIC_PORT_IN | PIC_PORT_TEXT);
+
+  pic_load(pic, port);
+
+  pic_close_port(pic, port);
 
   return pic_undef_value();
 }
diff --git a/contrib/20.r7rs/src/mutable-string.c b/contrib/20.r7rs/src/mutable-string.c
index 85db9be0..01887976 100644
--- a/contrib/20.r7rs/src/mutable-string.c
+++ b/contrib/20.r7rs/src/mutable-string.c
@@ -4,13 +4,16 @@ void
 pic_str_set(pic_state *pic, pic_str *str, size_t i, char c)
 {
   pic_str *x, *y, *z, *tmp;
+  char buf[1];
 
   if (pic_str_len(str) <= i) {
     pic_errorf(pic, "index out of range %d", i);
   }
 
+  buf[0] = c;
+
   x = pic_str_sub(pic, str, 0, i);
-  y = pic_make_str_fill(pic, 1, c);
+  y = pic_make_str(pic, buf, 1);
   z = pic_str_sub(pic, str, i + 1, pic_str_len(str));
 
   tmp = pic_str_cat(pic, x, pic_str_cat(pic, y, z));
diff --git a/extlib/benz/attr.c b/extlib/benz/attr.c
index 3e0bb192..ca11fa07 100644
--- a/extlib/benz/attr.c
+++ b/extlib/benz/attr.c
@@ -22,13 +22,13 @@ pic_attr(pic_state *pic, pic_value obj)
 pic_value
 pic_attr_ref(pic_state *pic, pic_value obj, const char *key)
 {
-  return pic_dict_ref(pic, pic_attr(pic, obj), pic_intern_cstr(pic, key));
+  return pic_dict_ref(pic, pic_attr(pic, obj), pic_intern(pic, key));
 }
 
 void
 pic_attr_set(pic_state *pic, pic_value obj, const char *key, pic_value v)
 {
-  pic_dict_set(pic, pic_attr(pic, obj), pic_intern_cstr(pic, key), v);
+  pic_dict_set(pic, pic_attr(pic, obj), pic_intern(pic, key), v);
 }
 
 static pic_value
diff --git a/extlib/benz/debug.c b/extlib/benz/debug.c
index 040b12a8..7d682f0f 100644
--- a/extlib/benz/debug.c
+++ b/extlib/benz/debug.c
@@ -45,7 +45,7 @@ pic_print_backtrace(pic_state *pic, xFILE *file)
     pic_value elem, it;
 
     e = pic_error_ptr(pic->err);
-    if (e->type != pic_intern_cstr(pic, "")) {
+    if (e->type != pic_intern(pic, "")) {
       pic_fwrite(pic, pic_obj_value(e->type), file);
       xfprintf(pic, file, " ");
     }
diff --git a/extlib/benz/error.c b/extlib/benz/error.c
index 1386ab63..c50fc85d 100644
--- a/extlib/benz/error.c
+++ b/extlib/benz/error.c
@@ -47,22 +47,6 @@ pic_errorf(pic_state *pic, const char *fmt, ...)
   pic_error(pic, msg, irrs);
 }
 
-const char *
-pic_errmsg(pic_state *pic)
-{
-  pic_str *str;
-
-  assert(! pic_invalid_p(pic->err));
-
-  if (! pic_error_p(pic->err)) {
-    str = pic_format(pic, "~s", pic->err);
-  } else {
-    str = pic_error_ptr(pic->err)->msg;
-  }
-
-  return pic_str_cstr(pic, str);
-}
-
 pic_value
 pic_native_exception_handler(pic_state *pic)
 {
@@ -158,7 +142,7 @@ pic_error(pic_state *pic, const char *msg, pic_value irrs)
 {
   struct pic_error *e;
 
-  e = pic_make_error(pic, pic_intern_cstr(pic, ""), msg, irrs);
+  e = pic_make_error(pic, pic_intern(pic, ""), msg, irrs);
 
   pic_raise(pic, pic_obj_value(e));
 }
@@ -212,22 +196,6 @@ pic_error_error(pic_state *pic)
   pic_error(pic, str, pic_list_by_array(pic, argc, argv));
 }
 
-static pic_value
-pic_error_make_error_object(pic_state *pic)
-{
-  struct pic_error *e;
-  pic_sym *type;
-  pic_str *msg;
-  size_t argc;
-  pic_value *argv;
-
-  pic_get_args(pic, "ms*", &type, &msg, &argc, &argv);
-
-  e = pic_make_error(pic, type, pic_str_cstr(pic, msg), pic_list_by_array(pic, argc, argv));
-
-  return pic_obj_value(e);
-}
-
 static pic_value
 pic_error_error_object_p(pic_state *pic)
 {
@@ -275,7 +243,6 @@ pic_init_error(pic_state *pic)
   pic_defun(pic, "raise", pic_error_raise);
   pic_defun(pic, "raise-continuable", pic_error_raise_continuable);
   pic_defun(pic, "error", pic_error_error);
-  pic_defun(pic, "make-error-object", pic_error_make_error_object);
   pic_defun(pic, "error-object?", pic_error_error_object_p);
   pic_defun(pic, "error-object-message", pic_error_error_object_message);
   pic_defun(pic, "error-object-irritants", pic_error_error_object_irritants);
diff --git a/extlib/benz/gc.c b/extlib/benz/gc.c
index 878c500e..4651ff35 100644
--- a/extlib/benz/gc.c
+++ b/extlib/benz/gc.c
@@ -487,12 +487,6 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     }
     break;
   }
-  case PIC_TT_BOX: {
-    struct pic_box *box = (struct pic_box *)obj;
-
-    gc_mark(pic, box->value);
-    break;
-  }
   case PIC_TT_NIL:
   case PIC_TT_BOOL:
 #if PIC_ENABLE_FLOAT
@@ -739,9 +733,6 @@ gc_finalize_object(pic_state *pic, struct pic_object *obj)
   case PIC_TT_CP: {
     break;
   }
-  case PIC_TT_BOX: {
-    break;
-  }
   case PIC_TT_NIL:
   case PIC_TT_BOOL:
 #if PIC_ENABLE_FLOAT
diff --git a/extlib/benz/include/picrin.h b/extlib/benz/include/picrin.h
index 585a5dec..54c68494 100644
--- a/extlib/benz/include/picrin.h
+++ b/extlib/benz/include/picrin.h
@@ -144,7 +144,6 @@ void *pic_malloc(pic_state *, size_t);
 void *pic_realloc(pic_state *, void *, size_t);
 void *pic_calloc(pic_state *, size_t, size_t);
 struct pic_object *pic_obj_alloc(pic_state *, size_t, enum pic_tt);
-struct pic_object *pic_obj_alloc_unsafe(pic_state *, size_t, enum pic_tt);
 void pic_free(pic_state *, void *);
 
 void pic_gc_run(pic_state *);
@@ -173,14 +172,14 @@ bool pic_eq_p(pic_value, pic_value);
 bool pic_eqv_p(pic_value, pic_value);
 bool pic_equal_p(pic_state *, pic_value, pic_value);
 
-pic_sym *pic_intern(pic_state *, pic_str *);
-pic_sym *pic_intern_cstr(pic_state *, const char *);
+pic_sym *pic_intern(pic_state *, const char *);
+pic_sym *pic_intern_str(pic_state *, pic_str *);
 const char *pic_symbol_name(pic_state *, pic_sym *);
 
 pic_value pic_read(pic_state *, struct pic_port *);
 pic_value pic_read_cstr(pic_state *, const char *);
 
-void pic_load_port(pic_state *, struct pic_port *);
+void pic_load(pic_state *, struct pic_port *);
 void pic_load_cstr(pic_state *, const char *);
 
 void pic_define(pic_state *, const char *, pic_value);
@@ -209,7 +208,6 @@ pic_value pic_apply5(pic_state *, struct pic_proc *, pic_value, pic_value, pic_v
 pic_value pic_apply_trampoline(pic_state *, struct pic_proc *, size_t, pic_value *);
 pic_value pic_apply_trampoline_list(pic_state *, struct pic_proc *, pic_value);
 pic_value pic_eval(pic_state *, pic_value, struct pic_env *);
-struct pic_proc *pic_compile(pic_state *, pic_value, struct pic_env *);
 
 struct pic_proc *pic_make_var(pic_state *, pic_value, struct pic_proc *);
 
@@ -233,9 +231,9 @@ void pic_export(pic_state *, pic_sym *);
 PIC_NORETURN void pic_panic(pic_state *, const char *);
 PIC_NORETURN void pic_errorf(pic_state *, const char *, ...);
 void pic_warnf(pic_state *, const char *, ...);
-const char *pic_errmsg(pic_state *);
 pic_str *pic_get_backtrace(pic_state *);
 void pic_print_backtrace(pic_state *, xFILE *);
+
 struct pic_dict *pic_attr(pic_state *, pic_value);
 pic_value pic_attr_ref(pic_state *, pic_value, const char *);
 void pic_attr_set(pic_state *, pic_value, const char *, pic_value);
@@ -271,7 +269,6 @@ pic_value pic_fdisplay(pic_state *, pic_value, xFILE *);
 #include "picrin/symbol.h"
 #include "picrin/vector.h"
 #include "picrin/reg.h"
-#include "picrin/box.h"
 
 #if defined(__cplusplus)
 }
diff --git a/extlib/benz/include/picrin/box.h b/extlib/benz/include/picrin/box.h
deleted file mode 100644
index edce0f0d..00000000
--- a/extlib/benz/include/picrin/box.h
+++ /dev/null
@@ -1,53 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_BOX_H
-#define PICRIN_BOX_H
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_box {
-  PIC_OBJECT_HEADER
-  pic_value value;
-};
-
-#define pic_box_p(v) (pic_type(v) == PIC_TT_BOX)
-#define pic_box_ptr(o) ((struct pic_box *)pic_ptr(o))
-
-PIC_INLINE pic_value
-pic_box(pic_state *pic, pic_value value)
-{
-  struct pic_box *box;
-
-  box = (struct pic_box *)pic_obj_alloc(pic, sizeof(struct pic_box), PIC_TT_BOX);
-  box->value = value;
-
-  return pic_obj_value(box);
-}
-
-PIC_INLINE pic_value
-pic_unbox(pic_state *pic, pic_value box)
-{
-  if (! pic_box_p(box)) {
-    pic_errorf(pic, "box required");
-  }
-  return pic_box_ptr(box)->value;
-}
-
-PIC_INLINE void
-pic_set_box(pic_state *pic, pic_value box, pic_value value)
-{
-  if (! pic_box_p(box)) {
-    pic_errorf(pic, "box required");
-  }
-  pic_box_ptr(box)->value = value;
-}
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/extlib/benz/include/picrin/irep.h b/extlib/benz/include/picrin/irep.h
index aa230848..246a84e2 100644
--- a/extlib/benz/include/picrin/irep.h
+++ b/extlib/benz/include/picrin/irep.h
@@ -35,6 +35,7 @@ pic_sym *pic_resolve(pic_state *, pic_value, struct pic_env *);
 pic_value pic_expand(pic_state *, pic_value, struct pic_env *);
 pic_value pic_analyze(pic_state *, pic_value);
 struct pic_irep *pic_codegen(pic_state *, pic_value);
+struct pic_proc *pic_compile(pic_state *, pic_value, struct pic_env *);
 
 #if defined(__cplusplus)
 }
diff --git a/extlib/benz/include/picrin/string.h b/extlib/benz/include/picrin/string.h
index 2728e97b..b7448783 100644
--- a/extlib/benz/include/picrin/string.h
+++ b/extlib/benz/include/picrin/string.h
@@ -22,7 +22,6 @@ void pic_rope_decref(pic_state *, struct pic_rope *);
 
 pic_str *pic_make_str(pic_state *, const char * /* nullable */, size_t);
 pic_str *pic_make_str_cstr(pic_state *, const char *);
-pic_str *pic_make_str_fill(pic_state *, size_t, char);
 
 char pic_str_ref(pic_state *, pic_str *, size_t);
 size_t pic_str_len(pic_str *);
diff --git a/extlib/benz/include/picrin/type.h b/extlib/benz/include/picrin/type.h
index 65156780..e6626960 100644
--- a/extlib/benz/include/picrin/type.h
+++ b/extlib/benz/include/picrin/type.h
@@ -2,8 +2,8 @@
  * See Copyright Notice in picrin.h
  */
 
-#ifndef PICRIN_VALUE_H
-#define PICRIN_VALUE_H
+#ifndef PICRIN_TYPE_H
+#define PICRIN_TYPE_H
 
 #if defined(__cplusplus)
 extern "C" {
@@ -163,7 +163,6 @@ enum pic_tt {
   PIC_TT_DATA,
   PIC_TT_DICT,
   PIC_TT_REG,
-  PIC_TT_BOX,
   PIC_TT_RECORD,
   PIC_TT_CXT,
   PIC_TT_IREP,
@@ -338,8 +337,6 @@ pic_type_repr(enum pic_tt tt)
     return "reg";
   case PIC_TT_RECORD:
     return "record";
-  case PIC_TT_BOX:
-    return "box";
   case PIC_TT_CP:
     return "checkpoint";
   }
diff --git a/extlib/benz/include/picrin/vector.h b/extlib/benz/include/picrin/vector.h
index 514ecb4b..2d845308 100644
--- a/extlib/benz/include/picrin/vector.h
+++ b/extlib/benz/include/picrin/vector.h
@@ -18,8 +18,7 @@ struct pic_vector {
 #define pic_vec_p(v) (pic_type(v) == PIC_TT_VECTOR)
 #define pic_vec_ptr(o) ((struct pic_vector *)pic_ptr(o))
 
-struct pic_vector *pic_make_vec(pic_state *, size_t);
-struct pic_vector *pic_make_vec_from_list(pic_state *, pic_value);
+pic_vec *pic_make_vec(pic_state *, size_t);
 
 #if defined(__cplusplus)
 }
diff --git a/extlib/benz/load.c b/extlib/benz/load.c
index cd609afe..32e6f152 100644
--- a/extlib/benz/load.c
+++ b/extlib/benz/load.c
@@ -5,7 +5,7 @@
 #include "picrin.h"
 
 void
-pic_load_port(pic_state *pic, struct pic_port *port)
+pic_load(pic_state *pic, struct pic_port *port)
 {
   pic_value form;
   size_t ai = pic_gc_arena_preserve(pic);
@@ -23,7 +23,7 @@ pic_load_cstr(pic_state *pic, const char *src)
   struct pic_port *port = pic_open_input_string(pic, src);
 
   pic_try {
-    pic_load_port(pic, port);
+    pic_load(pic, port);
   }
   pic_catch {
     pic_close_port(pic, port);
diff --git a/extlib/benz/macro.c b/extlib/benz/macro.c
index cac07fd5..8bca193f 100644
--- a/extlib/benz/macro.c
+++ b/extlib/benz/macro.c
@@ -56,7 +56,7 @@ pic_uniq(pic_state *pic, pic_value var)
 
   str = pic_format(pic, "%s.%d", pic_symbol_name(pic, pic_var_name(pic, var)), pic->ucnt++);
 
-  return pic_intern(pic, str);
+  return pic_intern_str(pic, str);
 }
 
 pic_sym *
diff --git a/extlib/benz/port.c b/extlib/benz/port.c
index 337d0ecd..9b4b605d 100644
--- a/extlib/benz/port.c
+++ b/extlib/benz/port.c
@@ -103,7 +103,7 @@ file_error(pic_state *pic, const char *msg)
 {
   struct pic_error *e;
 
-  e = pic_make_error(pic, pic_intern_cstr(pic, "file"), msg, pic_nil_value());
+  e = pic_make_error(pic, pic_intern(pic, "file"), msg, pic_nil_value());
 
   pic_raise(pic, pic_obj_value(e));
 }
diff --git a/extlib/benz/proc.c b/extlib/benz/proc.c
index 4c00885b..d7a5bca1 100644
--- a/extlib/benz/proc.c
+++ b/extlib/benz/proc.c
@@ -42,19 +42,19 @@ pic_proc_env(pic_state *pic, struct pic_proc *proc)
 bool
 pic_proc_env_has(pic_state *pic, struct pic_proc *proc, const char *key)
 {
-  return pic_dict_has(pic, pic_proc_env(pic, proc), pic_intern_cstr(pic, key));
+  return pic_dict_has(pic, pic_proc_env(pic, proc), pic_intern(pic, key));
 }
 
 pic_value
 pic_proc_env_ref(pic_state *pic, struct pic_proc *proc, const char *key)
 {
-  return pic_dict_ref(pic, pic_proc_env(pic, proc), pic_intern_cstr(pic, key));
+  return pic_dict_ref(pic, pic_proc_env(pic, proc), pic_intern(pic, key));
 }
 
 void
 pic_proc_env_set(pic_state *pic, struct pic_proc *proc, const char *key, pic_value val)
 {
-  pic_dict_set(pic, pic_proc_env(pic, proc), pic_intern_cstr(pic, key), val);
+  pic_dict_set(pic, pic_proc_env(pic, proc), pic_intern(pic, key), val);
 }
 
 static pic_value
diff --git a/extlib/benz/read.c b/extlib/benz/read.c
index 77cce237..3c13fd03 100644
--- a/extlib/benz/read.c
+++ b/extlib/benz/read.c
@@ -14,7 +14,7 @@ read_error(pic_state *pic, const char *msg)
 {
   struct pic_error *e;
 
-  e = pic_make_error(pic, pic_intern_cstr(pic, "read"), msg, pic_nil_value());
+  e = pic_make_error(pic, pic_intern(pic, "read"), msg, pic_nil_value());
 
   pic_raise(pic, pic_obj_value(e));
 }
@@ -216,7 +216,7 @@ read_symbol(pic_state *pic, struct pic_port *port, int c)
     buf[len] = 0;
   }
 
-  sym = pic_intern_cstr(pic, buf);
+  sym = pic_intern(pic, buf);
   pic_free(pic, buf);
 
   return pic_obj_value(sym);
@@ -537,7 +537,7 @@ read_pipe(pic_state *pic, struct pic_port *port, int c)
   }
   buf[cnt] = '\0';
 
-  sym = pic_intern_cstr(pic, buf);
+  sym = pic_intern(pic, buf);
   pic_free(pic, buf);
 
   return pic_obj_value(sym);
@@ -643,11 +643,19 @@ read_pair(pic_state *pic, struct pic_port *port, int c)
 static pic_value
 read_vector(pic_state *pic, struct pic_port *port, int c)
 {
-  pic_value list;
+  pic_value list, it, elem;
+  pic_vec *vec;
+  size_t i = 0;
 
   list = read(pic, port, c);
 
-  return pic_obj_value(pic_make_vec_from_list(pic, list));
+  vec = pic_make_vec(pic, pic_length(pic, list));
+
+  pic_for_each (elem, list, it) {
+    vec->data[i++] = elem;
+  }
+
+  return pic_obj_value(vec);
 }
 
 static pic_value
diff --git a/extlib/benz/record.c b/extlib/benz/record.c
index dfa21908..db14159e 100644
--- a/extlib/benz/record.c
+++ b/extlib/benz/record.c
@@ -15,7 +15,7 @@ pic_make_record(pic_state *pic, pic_value rectype)
   rec = (struct pic_record *)pic_obj_alloc(pic, sizeof(struct pic_record), PIC_TT_RECORD);
   rec->data = data;
 
-  pic_record_set(pic, rec, pic_intern_cstr(pic, "@@type"), rectype);
+  pic_record_set(pic, rec, pic_intern(pic, "@@type"), rectype);
 
   return rec;
 }
@@ -23,7 +23,7 @@ pic_make_record(pic_state *pic, pic_value rectype)
 pic_value
 pic_record_type(pic_state *pic, struct pic_record *rec)
 {
-  return pic_record_ref(pic, rec, pic_intern_cstr(pic, "@@type"));
+  return pic_record_ref(pic, rec, pic_intern(pic, "@@type"));
 }
 
 pic_value
diff --git a/extlib/benz/state.c b/extlib/benz/state.c
index 2fb447a3..8e03f6c4 100644
--- a/extlib/benz/state.c
+++ b/extlib/benz/state.c
@@ -15,7 +15,7 @@ pic_set_argv(pic_state *pic, int argc, char *argv[], char **envp)
 void
 pic_add_feature(pic_state *pic, const char *feature)
 {
-  pic_push(pic, pic_obj_value(pic_intern_cstr(pic, feature)), pic->features);
+  pic_push(pic, pic_obj_value(pic_intern(pic, feature)), pic->features);
 }
 
 void pic_init_undef(pic_state *);
@@ -113,10 +113,10 @@ pic_features(pic_state *pic)
 #define DONE pic_gc_arena_restore(pic, ai);
 
 #define define_builtin_syntax(uid, name)                                \
-  pic_define_syntactic_keyword_(pic, pic->lib->env, pic_intern_cstr(pic, name), uid)
+  pic_define_syntactic_keyword_(pic, pic->lib->env, pic_intern(pic, name), uid)
 
 #define VM(uid, name)                                                   \
-  pic_define_syntactic_keyword_(pic, pic->lib->env, pic_intern_cstr(pic, name), uid)
+  pic_define_syntactic_keyword_(pic, pic->lib->env, pic_intern(pic, name), uid)
 
 #define VM3(name)                                       \
   pic->c##name = pic_vm_gref_slot(pic, pic->u##name);
@@ -343,7 +343,7 @@ pic_open(pic_allocf allocf, void *userdata)
 
   ai = pic_gc_arena_preserve(pic);
 
-#define S(slot,name) pic->slot = pic_intern_cstr(pic, name)
+#define S(slot,name) pic->slot = pic_intern(pic, name)
 
   S(sQUOTE, "quote");
   S(sQUASIQUOTE, "quasiquote");
@@ -364,7 +364,7 @@ pic_open(pic_allocf allocf, void *userdata)
 
   pic_gc_arena_restore(pic, ai);
 
-#define U(slot,name) pic->slot = pic_uniq(pic, pic_obj_value(pic_intern_cstr(pic, name)))
+#define U(slot,name) pic->slot = pic_uniq(pic, pic_obj_value(pic_intern(pic, name)))
 
   U(uDEFINE, "define");
   U(uLAMBDA, "lambda");
diff --git a/extlib/benz/string.c b/extlib/benz/string.c
index 9d1060c3..f94dfd50 100644
--- a/extlib/benz/string.c
+++ b/extlib/benz/string.c
@@ -240,25 +240,6 @@ pic_make_str_cstr(pic_state *pic, const char *cstr)
   return pic_make_str(pic, cstr, strlen(cstr));
 }
 
-pic_str *
-pic_make_str_fill(pic_state *pic, size_t len, char fill)
-{
-  size_t i;
-  char *buf = pic_malloc(pic, len);
-  pic_str *str;
-
-  for (i = 0; i < len; ++i) {
-    buf[i] = fill;
-  }
-  buf[i] = '\0';
-
-  str = pic_make_str(pic, buf, len);
-
-  pic_free(pic, buf);
-
-  return str;
-}
-
 size_t
 pic_str_len(pic_str *str)
 {
@@ -471,10 +452,18 @@ pic_str_make_string(pic_state *pic)
 {
   size_t len;
   char c = ' ';
+  char *buf;
+  pic_value ret;
 
   pic_get_args(pic, "k|c", &len, &c);
 
-  return pic_obj_value(pic_make_str_fill(pic, len, c));
+  buf = pic_malloc(pic, len);
+  memset(buf, c, len);
+
+  ret = pic_obj_value(pic_make_str(pic, buf, len));
+
+  pic_free(pic, buf);
+  return ret;
 }
 
 static pic_value
diff --git a/extlib/benz/symbol.c b/extlib/benz/symbol.c
index ba5fb47c..5dec1035 100644
--- a/extlib/benz/symbol.c
+++ b/extlib/benz/symbol.c
@@ -7,13 +7,13 @@
 KHASH_DEFINE(s, const char *, pic_sym *, kh_str_hash_func, kh_str_hash_equal)
 
 pic_sym *
-pic_intern(pic_state *pic, pic_str *str)
+pic_intern_str(pic_state *pic, pic_str *str)
 {
-  return pic_intern_cstr(pic, pic_str_cstr(pic, str));
+  return pic_intern(pic, pic_str_cstr(pic, str));
 }
 
 pic_sym *
-pic_intern_cstr(pic_state *pic, const char *cstr)
+pic_intern(pic_state *pic, const char *cstr)
 {
   khash_t(s) *h = &pic->syms;
   pic_sym *sym;
@@ -93,7 +93,7 @@ pic_symbol_string_to_symbol(pic_state *pic)
 
   pic_get_args(pic, "s", &str);
 
-  return pic_obj_value(pic_intern(pic, str));
+  return pic_obj_value(pic_intern_str(pic, str));
 }
 
 void
diff --git a/extlib/benz/vector.c b/extlib/benz/vector.c
index c3b914c1..a270ad69 100644
--- a/extlib/benz/vector.c
+++ b/extlib/benz/vector.c
@@ -19,22 +19,6 @@ pic_make_vec(pic_state *pic, size_t len)
   return vec;
 }
 
-struct pic_vector *
-pic_make_vec_from_list(pic_state *pic, pic_value data)
-{
-  struct pic_vector *vec;
-  size_t len, i;
-
-  len = pic_length(pic, data);
-
-  vec = pic_make_vec(pic, len);
-  for (i = 0; i < len; ++i) {
-    vec->data[i] = pic_car(pic, data);
-    data = pic_cdr(pic, data);
-  }
-  return vec;
-}
-
 static pic_value
 pic_vec_vector_p(pic_state *pic)
 {
diff --git a/extlib/benz/vm.c b/extlib/benz/vm.c
index 23a6ef46..4ab5a644 100644
--- a/extlib/benz/vm.c
+++ b/extlib/benz/vm.c
@@ -1114,7 +1114,7 @@ pic_define_(pic_state *pic, const char *name, pic_value val)
 {
   pic_sym *sym, *uid;
 
-  sym = pic_intern_cstr(pic, name);
+  sym = pic_intern(pic, name);
 
   if ((uid = pic_find_variable(pic, pic->lib->env, pic_obj_value(sym))) == NULL) {
     uid = pic_add_variable(pic, pic->lib->env, pic_obj_value(sym));
@@ -1131,7 +1131,7 @@ void
 pic_define(pic_state *pic, const char *name, pic_value val)
 {
   pic_define_(pic, name, val);
-  pic_export(pic, pic_intern_cstr(pic, name));
+  pic_export(pic, pic_intern(pic, name));
 }
 
 void
@@ -1144,7 +1144,7 @@ void
 pic_defun(pic_state *pic, const char *name, pic_func_t cfunc)
 {
   pic_defun_(pic, name, cfunc);
-  pic_export(pic, pic_intern_cstr(pic, name));
+  pic_export(pic, pic_intern(pic, name));
 }
 
 void
@@ -1157,7 +1157,7 @@ void
 pic_defvar(pic_state *pic, const char *name, pic_value init, struct pic_proc *conv)
 {
   pic_defvar_(pic, name, init, conv);
-  pic_export(pic, pic_intern_cstr(pic, name));
+  pic_export(pic, pic_intern(pic, name));
 }
 
 pic_value
@@ -1165,7 +1165,7 @@ pic_ref(pic_state *pic, struct pic_lib *lib, const char *name)
 {
   pic_sym *sym, *uid;
 
-  sym = pic_intern_cstr(pic, name);
+  sym = pic_intern(pic, name);
 
   if ((uid = pic_find_variable(pic, lib->env, pic_obj_value(sym))) == NULL) {
     pic_errorf(pic, "symbol \"%s\" not defined in library ~s", name, lib->name);
@@ -1179,7 +1179,7 @@ pic_set(pic_state *pic, struct pic_lib *lib, const char *name, pic_value val)
 {
   pic_sym *sym, *uid;
 
-  sym = pic_intern_cstr(pic, name);
+  sym = pic_intern(pic, name);
 
   if ((uid = pic_find_variable(pic, lib->env, pic_obj_value(sym))) == NULL) {
     pic_errorf(pic, "symbol \"%s\" not defined in library ~s", name, lib->name);