From de362c8f37340cf0f2c6e93b8339498a623b54a7 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 16:47:23 +0900
Subject: [PATCH 01/27] strict error check on vector manipulation

---
 vector.c | 56 ++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 38 insertions(+), 18 deletions(-)

diff --git a/vector.c b/vector.c
index 2a3099f7..775895d3 100644
--- a/vector.c
+++ b/vector.c
@@ -26,11 +26,11 @@ struct pic_vector *
 pic_make_vec_from_list(pic_state *pic, pic_value data)
 {
   struct pic_vector *vec;
-  size_t i, len;
+  int len, i;
 
   len = pic_length(pic, data);
 
-  vec = pic_make_vec(pic, len);
+  vec = pic_make_vec(pic, (size_t)len);
   for (i = 0; i < len; ++i) {
     vec->data[i] = pic_car(pic, data);
     data = pic_cdr(pic, data);
@@ -77,7 +77,11 @@ pic_vec_make_vector(pic_state *pic)
 
   n = pic_get_args(pic, "i|o", &k, &v);
 
-  vec = pic_make_vec(pic, k);
+  if (k < 0) {
+    pic_errorf(pic, "make-vector: vector length must be non-negative");
+  }
+
+  vec = pic_make_vec(pic, (size_t)k);
   if (n == 2) {
     for (i = 0; i < (size_t)k; ++i) {
       vec->data[i] = v;
@@ -93,7 +97,7 @@ pic_vec_vector_length(pic_state *pic)
 
   pic_get_args(pic, "v", &v);
 
-  return pic_int_value(v->len);
+  return pic_int_value((int)v->len);
 }
 
 static pic_value
@@ -138,7 +142,7 @@ pic_vec_vector_copy_i(pic_state *pic)
   case 3:
     start = 0;
   case 4:
-    end = from->len;
+    end = (int)from->len;
   }
 
   if (to == from && (start <= at && at < end)) {
@@ -169,10 +173,14 @@ pic_vec_vector_copy(pic_state *pic)
   case 1:
     start = 0;
   case 2:
-    end = vec->len;
+    end = (int)vec->len;
   }
 
-  to = pic_make_vec(pic, end - start);
+  if (end - start < 0) {
+    pic_errorf(pic, "vector-copy: end index must not be less than start index");
+  }
+
+  to = pic_make_vec(pic, (size_t)(end - start));
   while (start < end) {
     to->data[i++] = vec->data[start++];
   }
@@ -221,7 +229,7 @@ pic_vec_vector_fill_i(pic_state *pic)
   case 2:
     start = 0;
   case 3:
-    end = vec->len;
+    end = (int)vec->len;
   }
 
   while (start < end) {
@@ -300,7 +308,7 @@ pic_vec_list_to_vector(pic_state *pic)
 
   pic_get_args(pic, "o", &list);
 
-  vec = pic_make_vec(pic, pic_length(pic, list));
+  vec = pic_make_vec(pic, (size_t)pic_length(pic, list));
 
   data = vec->data;
 
@@ -323,7 +331,7 @@ pic_vec_vector_to_list(pic_state *pic)
   case 1:
     start = 0;
   case 2:
-    end = vec->len;
+    end = (int)vec->len;
   }
 
   list = pic_nil_value();
@@ -348,10 +356,14 @@ pic_vec_vector_to_string(pic_state *pic)
   case 1:
     start = 0;
   case 2:
-    end = vec->len;
+    end = (int)vec->len;
   }
 
-  buf = pic_alloc(pic, end - start);
+  if (end - start < 0) {
+    pic_errorf(pic, "vector->string: end index must not be less than start index");
+  }
+
+  buf = pic_alloc(pic, (size_t)(end - start));
 
   for (i = start; i < end; ++i) {
     pic_assert_type(pic, vec->data[i], char);
@@ -359,7 +371,7 @@ pic_vec_vector_to_string(pic_state *pic)
     buf[i - start] = pic_char(vec->data[i]);
   }
 
-  str = pic_make_str(pic, buf, end - start);
+  str = pic_make_str(pic, buf, (size_t)(end - start));
   pic_free(pic, buf);
 
   return pic_obj_value(str);
@@ -369,7 +381,8 @@ static pic_value
 pic_vec_string_to_vector(pic_state *pic)
 {
   pic_str *str;
-  int n, start, end, i;
+  int n, start, end;
+  size_t i;
   pic_vec *vec;
 
   n = pic_get_args(pic, "s|ii", &str, &start, &end);
@@ -378,13 +391,20 @@ pic_vec_string_to_vector(pic_state *pic)
   case 1:
     start = 0;
   case 2:
-    end = pic_strlen(str);
+    end = (int)pic_strlen(str);
   }
 
-  vec = pic_make_vec(pic, end - start);
+  if (start < 0) {
+    pic_errorf(pic, "string->vector: index must non-negative");
+  }
+  if (end - start < 0) {
+    pic_errorf(pic, "string->vector: end index must not be less than start index");
+  }
 
-  for (i = start; i < end; ++i) {
-    vec->data[i - start] = pic_char_value(pic_str_ref(pic, str, i));
+  vec = pic_make_vec(pic, (size_t)(end - start));
+
+  for (i = 0; i < (size_t)(end - start); ++i) {
+    vec->data[i] = pic_char_value(pic_str_ref(pic, str, i + (size_t)start));
   }
   return pic_obj_value(vec);
 }

From a75ff9f2b0790d3398f969cc3a4079b69f10967a Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:04:20 +0900
Subject: [PATCH 02/27] argc should be int

---
 blob.c   |  5 +++--
 bool.c   |  2 +-
 char.c   |  3 +--
 cont.c   |  4 ++--
 dict.c   |  2 +-
 error.c  |  4 ++--
 lib.c    |  8 ++++----
 number.c |  9 +++------
 pair.c   | 10 ++++------
 proc.c   |  2 +-
 string.c | 14 +++++++-------
 symbol.c |  2 +-
 vector.c | 12 +++++++-----
 vm.c     |  4 ++--
 14 files changed, 39 insertions(+), 42 deletions(-)

diff --git a/blob.c b/blob.c
index e927f4ff..d87afc83 100644
--- a/blob.c
+++ b/blob.c
@@ -33,7 +33,7 @@ static pic_value
 pic_blob_bytevector(pic_state *pic)
 {
   pic_value *argv;
-  size_t argc, i;
+  int argc, i;
   pic_blob *blob;
   unsigned char *data;
 
@@ -176,7 +176,8 @@ pic_blob_bytevector_copy(pic_state *pic)
 static pic_value
 pic_blob_bytevector_append(pic_state *pic)
 {
-  size_t argc, i, j, len;
+  size_t j, len;
+  int argc, i;
   pic_value *argv;
   pic_blob *blob;
 
diff --git a/bool.c b/bool.c
index 8f8c75f1..ff5528e9 100644
--- a/bool.c
+++ b/bool.c
@@ -172,7 +172,7 @@ pic_bool_boolean_p(pic_state *pic)
 static pic_value
 pic_bool_boolean_eq_p(pic_state *pic)
 {
-  size_t argc, i;
+  int argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
diff --git a/char.c b/char.c
index 98eed6f7..f08fcdd0 100644
--- a/char.c
+++ b/char.c
@@ -42,9 +42,8 @@ pic_char_integer_to_char(pic_state *pic)
   static pic_value					\
   pic_char_##name##_p(pic_state *pic)			\
   {							\
-    size_t argc;					\
+    int argc, i;                                        \
     pic_value *argv;					\
-    size_t i;						\
     char c, d;						\
     							\
     pic_get_args(pic, "cc*", &c, &d, &argc, &argv);	\
diff --git a/cont.c b/cont.c
index f010f532..39ec7861 100644
--- a/cont.c
+++ b/cont.c
@@ -96,7 +96,7 @@ pic_load_point(pic_state *pic, struct pic_escape *escape)
 noreturn static pic_value
 escape_call(pic_state *pic)
 {
-  size_t argc;
+  int argc;
   pic_value *argv;
   struct pic_data *e;
 
@@ -251,7 +251,7 @@ pic_cont_dynamic_wind(pic_state *pic)
 static pic_value
 pic_cont_values(pic_state *pic)
 {
-  size_t argc;
+  int argc;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
diff --git a/dict.c b/dict.c
index 13200c08..2a8fcd41 100644
--- a/dict.c
+++ b/dict.c
@@ -142,7 +142,7 @@ pic_dict_dictionary(pic_state *pic)
 {
   struct pic_dict *dict;
   pic_value *argv;
-  size_t argc, i;
+  int argc, i;
 
   pic_get_args(pic, "*", &argc, &argv);
 
diff --git a/error.c b/error.c
index b25cbb42..568e523b 100644
--- a/error.c
+++ b/error.c
@@ -243,7 +243,7 @@ noreturn static pic_value
 pic_error_error(pic_state *pic)
 {
   const char *str;
-  size_t argc;
+  int argc;
   pic_value *argv;
 
   pic_get_args(pic, "z*", &str, &argc, &argv);
@@ -257,7 +257,7 @@ pic_error_make_error_object(pic_state *pic)
   struct pic_error *e;
   pic_sym type;
   pic_str *msg;
-  size_t argc;
+  int argc;
   pic_value *argv;
 
   pic_get_args(pic, "ms*", &type, &msg, &argc, &argv);
diff --git a/lib.c b/lib.c
index 37cba2bd..cd760f18 100644
--- a/lib.c
+++ b/lib.c
@@ -253,7 +253,7 @@ static pic_value
 pic_lib_condexpand(pic_state *pic)
 {
   pic_value *clauses;
-  size_t argc, i;
+  int argc, i;
 
   pic_get_args(pic, "*", &argc, &clauses);
 
@@ -269,7 +269,7 @@ pic_lib_condexpand(pic_state *pic)
 static pic_value
 pic_lib_import(pic_state *pic)
 {
-  size_t argc, i;
+  int argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -284,7 +284,7 @@ pic_lib_import(pic_state *pic)
 static pic_value
 pic_lib_export(pic_state *pic)
 {
-  size_t argc, i;
+  int argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -300,7 +300,7 @@ static pic_value
 pic_lib_define_library(pic_state *pic)
 {
   struct pic_lib *prev = pic->lib;
-  size_t argc, i;
+  int argc, i;
   pic_value spec, *argv;
 
   pic_get_args(pic, "o*", &spec, &argc, &argv);
diff --git a/number.c b/number.c
index 2ed93a79..c72f58ca 100644
--- a/number.c
+++ b/number.c
@@ -162,9 +162,8 @@ pic_number_nan_p(pic_state *pic)
   static pic_value					\
   pic_number_##name(pic_state *pic)			\
   {							\
-    size_t argc;					\
+    int argc, i;                                        \
     pic_value *argv;					\
-    size_t i;						\
     double f,g;						\
     							\
     pic_get_args(pic, "ff*", &f, &g, &argc, &argv);	\
@@ -198,9 +197,8 @@ DEFINE_ARITH_CMP(>=, ge)
   static pic_value                                              \
   pic_number_##name(pic_state *pic)                             \
   {                                                             \
-    size_t argc;                                                \
+    int argc, i;                                                \
     pic_value *argv;                                            \
-    size_t i;                                                   \
     double f;                                                   \
     bool e = true;                                              \
                                                                 \
@@ -230,9 +228,8 @@ DEFINE_ARITH_OP(*, mul, 1)
   static pic_value                                                      \
   pic_number_##name(pic_state *pic)                                     \
   {                                                                     \
-   size_t argc;                                                         \
+    int argc, i;                                                        \
    pic_value *argv;                                                     \
-   size_t i;                                                            \
    double f;                                                            \
    bool e;                                                              \
                                                                         \
diff --git a/pair.c b/pair.c
index ee2263c7..b6def852 100644
--- a/pair.c
+++ b/pair.c
@@ -544,7 +544,7 @@ pic_pair_make_list(pic_state *pic)
 static pic_value
 pic_pair_list(pic_state *pic)
 {
-  size_t argc;
+  int argc;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -565,7 +565,7 @@ pic_pair_length(pic_state *pic)
 static pic_value
 pic_pair_append(pic_state *pic)
 {
-  size_t argc;
+  int argc;
   pic_value *args, list;
 
   pic_get_args(pic, "*", &argc, &args);
@@ -641,9 +641,8 @@ static pic_value
 pic_pair_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  size_t argc;
+  int argc, i;
   pic_value *args;
-  int i;
   pic_value cars, ret;
 
   pic_get_args(pic, "l*", &proc, &argc, &args);
@@ -670,9 +669,8 @@ static pic_value
 pic_pair_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  size_t argc;
+  int argc, i;
   pic_value *args;
-  int i;
   pic_value cars;
 
   pic_get_args(pic, "l*", &proc, &argc, &args);
diff --git a/proc.c b/proc.c
index 210f157d..0d67ddd7 100644
--- a/proc.c
+++ b/proc.c
@@ -61,7 +61,7 @@ pic_proc_apply(pic_state *pic)
 {
   struct pic_proc *proc;
   pic_value *args;
-  size_t argc;
+  int argc;
   pic_value arg_list;
 
   pic_get_args(pic, "l*", &proc, &argc, &args);
diff --git a/string.c b/string.c
index b53055f4..2372ea31 100644
--- a/string.c
+++ b/string.c
@@ -233,11 +233,10 @@ pic_str_string_p(pic_state *pic)
 static pic_value
 pic_str_string(pic_state *pic)
 {
-  size_t argc;
+  int argc, i;
   pic_value *argv;
   pic_str *str;
   char *buf;
-  size_t i;
 
   pic_get_args(pic, "*", &argc, &argv);
 
@@ -290,9 +289,8 @@ pic_str_string_ref(pic_state *pic)
   static pic_value                                                      \
   pic_str_string_##name(pic_state *pic)                                 \
   {                                                                     \
-    size_t argc;                                                        \
+    int argc, i;                                                        \
     pic_value *argv;                                                    \
-    size_t i;                                                           \
                                                                         \
     pic_get_args(pic, "*", &argc, &argv);                               \
                                                                         \
@@ -338,7 +336,7 @@ pic_str_string_copy(pic_state *pic)
 static pic_value
 pic_str_string_append(pic_state *pic)
 {
-  size_t argc, i;
+  int argc, i;
   pic_value *argv;
   pic_str *str;
 
@@ -358,8 +356,9 @@ static pic_value
 pic_str_string_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  size_t argc, i, len, j;
+  int argc, i;
   pic_value *argv, vals, val;
+  size_t len, j;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
@@ -396,7 +395,8 @@ static pic_value
 pic_str_string_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  size_t argc, i, len, j;
+  int argc, i;
+  size_t len, j;
   pic_value *argv, vals, val;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
diff --git a/symbol.c b/symbol.c
index 0cbbf78a..d6feab13 100644
--- a/symbol.c
+++ b/symbol.c
@@ -108,7 +108,7 @@ pic_symbol_symbol_p(pic_state *pic)
 static pic_value
 pic_symbol_symbol_eq_p(pic_state *pic)
 {
-  size_t argc, i;
+  int argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
diff --git a/vector.c b/vector.c
index 775895d3..4378e66c 100644
--- a/vector.c
+++ b/vector.c
@@ -51,10 +51,9 @@ pic_vec_vector_p(pic_state *pic)
 static pic_value
 pic_vec_vector(pic_state *pic)
 {
-  size_t argc;
+  int argc, i;
   pic_value *argv;
   pic_vec *vec;
-  size_t i;
 
   pic_get_args(pic, "*", &argc, &argv);
 
@@ -191,8 +190,9 @@ pic_vec_vector_copy(pic_state *pic)
 static pic_value
 pic_vec_vector_append(pic_state *pic)
 {
-  size_t argc, i, j, len;
+  int argc, i;
   pic_value *argv;
+  size_t j, len;
   pic_vec *vec;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -243,8 +243,9 @@ static pic_value
 pic_vec_vector_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  size_t argc, i, len, j;
+  int argc, i;
   pic_value *argv, vals;
+  size_t len, j;
   pic_vec *vec;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
@@ -275,8 +276,9 @@ static pic_value
 pic_vec_vector_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  size_t argc, i, len, j;
+  int argc, i;
   pic_value *argv, vals;
+  size_t len, j;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
diff --git a/vm.c b/vm.c
index 92af1ce7..a996742e 100644
--- a/vm.c
+++ b/vm.c
@@ -386,10 +386,10 @@ pic_get_args(pic_state *pic, const char *format, ...)
     }
   }
   if ('*' == c) {
-    size_t *n;
+    int *n;
     pic_value **argv;
 
-    n = va_arg(ap, size_t *);
+    n = va_arg(ap, int *);
     argv = va_arg(ap, pic_value **);
     if (i <= argc) {
       *n = argc - i;

From 7ab9708ed067588ca7451ae93703e82bf421fa12 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:09:52 +0900
Subject: [PATCH 03/27] passing array with a pair of int and pic_value *

---
 cont.c                | 14 +++++++-------
 include/picrin/cont.h |  4 ++--
 include/picrin/pair.h |  2 +-
 pair.c                |  2 +-
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/cont.c b/cont.c
index 39ec7861..4b980e4a 100644
--- a/cont.c
+++ b/cont.c
@@ -184,9 +184,9 @@ pic_values5(pic_state *pic, pic_value arg1, pic_value arg2, pic_value arg3, pic_
 }
 
 pic_value
-pic_values_by_array(pic_state *pic, size_t argc, pic_value *argv)
+pic_values_by_array(pic_state *pic, int argc, pic_value *argv)
 {
-  size_t i;
+  int i;
 
   for (i = 0; i < argc; ++i) {
     pic->sp[i] = argv[i];
@@ -200,7 +200,7 @@ pic_value
 pic_values_by_list(pic_state *pic, pic_value list)
 {
   pic_value v;
-  size_t i;
+  int i;
 
   i = 0;
   pic_for_each (v, list) {
@@ -211,11 +211,11 @@ pic_values_by_list(pic_state *pic, pic_value list)
   return pic_nil_p(list) ? pic_none_value() : pic->sp[0];
 }
 
-size_t
-pic_receive(pic_state *pic, size_t n, pic_value *argv)
+int
+pic_receive(pic_state *pic, int n, pic_value *argv)
 {
   pic_callinfo *ci;
-  size_t i, retc;
+  int i, retc;
 
   /* take info from discarded frame */
   ci = pic->ci + 1;
@@ -263,7 +263,7 @@ static pic_value
 pic_cont_call_with_values(pic_state *pic)
 {
   struct pic_proc *producer, *consumer;
-  size_t argc;
+  int argc;
   pic_value args[256];
 
   pic_get_args(pic, "ll", &producer, &consumer);
diff --git a/include/picrin/cont.h b/include/picrin/cont.h
index 645e6d9c..01e86e11 100644
--- a/include/picrin/cont.h
+++ b/include/picrin/cont.h
@@ -40,9 +40,9 @@ pic_value pic_values2(pic_state *, pic_value, pic_value);
 pic_value pic_values3(pic_state *, pic_value, pic_value, pic_value);
 pic_value pic_values4(pic_state *, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_values5(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value);
-pic_value pic_values_by_array(pic_state *, size_t, pic_value *);
+pic_value pic_values_by_array(pic_state *, int, pic_value *);
 pic_value pic_values_by_list(pic_state *, pic_value);
-size_t pic_receive(pic_state *, size_t, pic_value *);
+int pic_receive(pic_state *, int, pic_value *);
 
 pic_value pic_escape(pic_state *, struct pic_proc *);
 
diff --git a/include/picrin/pair.h b/include/picrin/pair.h
index 16c61863..49e3f73f 100644
--- a/include/picrin/pair.h
+++ b/include/picrin/pair.h
@@ -56,7 +56,7 @@ pic_value pic_list4(pic_state *, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list5(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list6(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list7(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value);
-pic_value pic_list_by_array(pic_state *, size_t, pic_value *);
+pic_value pic_list_by_array(pic_state *, int, pic_value *);
 pic_value pic_make_list(pic_state *, int, pic_value);
 
 #define pic_for_each(var, list)                                 \
diff --git a/pair.c b/pair.c
index b6def852..6a9687d8 100644
--- a/pair.c
+++ b/pair.c
@@ -160,7 +160,7 @@ pic_list7(pic_state *pic, pic_value obj1, pic_value obj2, pic_value obj3, pic_va
 }
 
 pic_value
-pic_list_by_array(pic_state *pic, size_t c, pic_value *vs)
+pic_list_by_array(pic_state *pic, int c, pic_value *vs)
 {
   pic_value v;
 

From 7b0ec3adde85bbaab2350493248f5a4aaad63eab Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:13:17 +0900
Subject: [PATCH 04/27] adjustment. amending for argc type change

---
 blob.c   |  2 +-
 vector.c | 12 +++++-------
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/blob.c b/blob.c
index d87afc83..da3907c3 100644
--- a/blob.c
+++ b/blob.c
@@ -39,7 +39,7 @@ pic_blob_bytevector(pic_state *pic)
 
   pic_get_args(pic, "*", &argc, &argv);
 
-  blob = pic_make_blob(pic, argc);
+  blob = pic_make_blob(pic, (size_t)argc);
 
   data = blob->data;
 
diff --git a/vector.c b/vector.c
index 4378e66c..6ae7f136 100644
--- a/vector.c
+++ b/vector.c
@@ -57,7 +57,7 @@ pic_vec_vector(pic_state *pic)
 
   pic_get_args(pic, "*", &argc, &argv);
 
-  vec = pic_make_vec(pic, argc);
+  vec = pic_make_vec(pic, (size_t)argc);
 
   for (i = 0; i < argc; ++i) {
     vec->data[i] = argv[i];
@@ -243,14 +243,13 @@ static pic_value
 pic_vec_vector_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i;
+  int argc, i, len, j;
   pic_value *argv, vals;
-  size_t len, j;
   pic_vec *vec;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
-  len = SIZE_MAX;
+  len = INT_MAX;
   for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], vec);
 
@@ -276,13 +275,12 @@ static pic_value
 pic_vec_vector_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i;
+  int argc, i, len, j;
   pic_value *argv, vals;
-  size_t len, j;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
-  len = SIZE_MAX;
+  len = INT_MAX;
   for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], vec);
 

From cb54f0e065db793256340be80ddaff8824cbdec9 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:36:00 +0900
Subject: [PATCH 05/27] int and size_t

---
 codegen.c | 11 +++++------
 vector.c  | 14 ++++++++------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/codegen.c b/codegen.c
index 55bb8587..050f18c2 100644
--- a/codegen.c
+++ b/codegen.c
@@ -490,7 +490,6 @@ analyze_if(analyze_state *state, pic_value obj, bool tailpos)
   switch (pic_length(pic, obj)) {
   default:
     pic_errorf(pic, "syntax error");
-    break;
   case 4:
     if_false = pic_list_ref(pic, obj, 3);
     FALLTHROUGH;
@@ -956,7 +955,7 @@ create_activation(codegen_context *cxt)
     if ((n = xh_val(xh_get_int(&regs, *var), size_t)) <= xv_size(&cxt->args) || (cxt->varg && n == xv_size(&cxt->args) + 1)) {
       /* copy arguments to capture variable area */
       cxt->code[cxt->clen].insn = OP_LREF;
-      cxt->code[cxt->clen].u.i = n;
+      cxt->code[cxt->clen].u.i = (int)n;
       cxt->clen++;
     } else {
       /* otherwise, just extend the stack */
@@ -1030,9 +1029,9 @@ pop_codegen_context(codegen_state *state)
   irep = (struct pic_irep *)pic_obj_alloc(pic, sizeof(struct pic_irep), PIC_TT_IREP);
   irep->name = state->cxt->name;
   irep->varg = state->cxt->varg;
-  irep->argc = xv_size(&state->cxt->args) + 1;
-  irep->localc = xv_size(&state->cxt->locals);
-  irep->capturec = xv_size(&state->cxt->captures);
+  irep->argc = (int)xv_size(&state->cxt->args) + 1;
+  irep->localc = (int)xv_size(&state->cxt->locals);
+  irep->capturec = (int)xv_size(&state->cxt->captures);
   irep->code = pic_realloc(pic, state->cxt->code, sizeof(pic_code) * state->cxt->clen);
   irep->clen = state->cxt->clen;
   irep->irep = pic_realloc(pic, state->cxt->irep, sizeof(struct pic_irep *) * state->cxt->ilen);
@@ -1067,7 +1066,7 @@ index_capture(codegen_state *state, pic_sym sym, int depth)
   for (i = 0; i < xv_size(&cxt->captures); ++i) {
     var = xv_get(&cxt->captures, i);
     if (*var == sym)
-      return i;
+      return (int)i;
   }
   return -1;
 }
diff --git a/vector.c b/vector.c
index 6ae7f136..ba0dc7c8 100644
--- a/vector.c
+++ b/vector.c
@@ -243,14 +243,15 @@ static pic_value
 pic_vec_vector_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i, len, j;
+  int argc;
+  size_t i, len, j;
   pic_value *argv, vals;
   pic_vec *vec;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = INT_MAX;
-  for (i = 0; i < argc; ++i) {
+  for (i = 0; i < (size_t)argc; ++i) {
     pic_assert_type(pic, argv[i], vec);
 
     len = len < pic_vec_ptr(argv[i])->len
@@ -262,7 +263,7 @@ pic_vec_vector_map(pic_state *pic)
 
   for (i = 0; i < len; ++i) {
     vals = pic_nil_value();
-    for (j = 0; j < argc; ++j) {
+    for (j = 0; j < (size_t)argc; ++j) {
       pic_push(pic, pic_vec_ptr(argv[j])->data[i], vals);
     }
     vec->data[i] = pic_apply(pic, proc, vals);
@@ -275,13 +276,14 @@ static pic_value
 pic_vec_vector_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i, len, j;
+  int argc;
+  size_t i, len, j;
   pic_value *argv, vals;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = INT_MAX;
-  for (i = 0; i < argc; ++i) {
+  for (i = 0; i < (size_t)argc; ++i) {
     pic_assert_type(pic, argv[i], vec);
 
     len = len < pic_vec_ptr(argv[i])->len
@@ -291,7 +293,7 @@ pic_vec_vector_for_each(pic_state *pic)
 
   for (i = 0; i < len; ++i) {
     vals = pic_nil_value();
-    for (j = 0; j < argc; ++j) {
+    for (j = 0; j < (size_t)argc; ++j) {
       pic_push(pic, pic_vec_ptr(argv[j])->data[i], vals);
     }
     pic_apply(pic, proc, vals);

From 315c17c8d41a53c832d2e883cb578dff39dbeb12 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:36:27 +0900
Subject: [PATCH 06/27] move stack overflow checker

---
 vm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/vm.c b/vm.c
index a996742e..58e5967f 100644
--- a/vm.c
+++ b/vm.c
@@ -581,7 +581,7 @@ pic_apply5(pic_state *pic, struct pic_proc *proc, pic_value arg1, pic_value arg2
 # define VM_LOOP_END } }
 #endif
 
-#define PUSH(v) ((pic->sp >= pic->stend) ? abort() : (*pic->sp++ = (v)))
+#define PUSH(v) (*pic->sp++ = (v))
 #define POP() (*--pic->sp)
 
 #define PUSHCI() (++pic->ci)
@@ -843,6 +843,10 @@ pic_apply(pic_state *pic, struct pic_proc *proc, pic_value argv)
 
       VM_CALL_PRINT;
 
+      if (pic->sp >= pic->stend) {
+        pic_panic(pic, "VM stack overflow");
+      }
+
       ci = PUSHCI();
       ci->argc = c.u.i;
       ci->retc = 1;

From 490472af2f662f51fe7918e1d907804b999f8d49 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:36:47 +0900
Subject: [PATCH 07/27] resolve VM's varaible shadows

---
 vm.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/vm.c b/vm.c
index 58e5967f..1eac9f91 100644
--- a/vm.c
+++ b/vm.c
@@ -650,11 +650,10 @@ pic_apply5(pic_state *pic, struct pic_proc *proc, pic_value arg1, pic_value arg2
 #endif
 
 pic_value
-pic_apply(pic_state *pic, struct pic_proc *proc, pic_value argv)
+pic_apply(pic_state *pic, struct pic_proc *proc, pic_value args)
 {
   pic_code c;
   size_t ai = pic_gc_arena_preserve(pic);
-  size_t argc, i;
   pic_code boot[2];
 
 #if PIC_DIRECT_THREADED_VM
@@ -674,26 +673,29 @@ pic_apply(pic_state *pic, struct pic_proc *proc, pic_value argv)
   pic_callinfo *cibase;
 #endif
 
-  if (! pic_list_p(argv)) {
+  if (! pic_list_p(args)) {
     pic_errorf(pic, "argv must be a proper list");
   }
+  else {
+    int argc, i;
 
-  argc = pic_length(pic, argv) + 1;
+    argc = pic_length(pic, args) + 1;
 
-  VM_BOOT_PRINT;
+    VM_BOOT_PRINT;
 
-  PUSH(pic_obj_value(proc));
-  for (i = 1; i < argc; ++i) {
-    PUSH(pic_car(pic, argv));
-    argv = pic_cdr(pic, argv);
+    PUSH(pic_obj_value(proc));
+    for (i = 1; i < argc; ++i) {
+      PUSH(pic_car(pic, args));
+      args = pic_cdr(pic, args);
+    }
+
+    /* boot! */
+    boot[0].insn = OP_CALL;
+    boot[0].u.i = argc;
+    boot[1].insn = OP_STOP;
+    pic->ip = boot;
   }
 
-  /* boot! */
-  boot[0].insn = OP_CALL;
-  boot[0].u.i = argc;
-  boot[1].insn = OP_STOP;
-  pic->ip = boot;
-
   VM_LOOP {
     CASE(OP_NOP) {
       NEXT;
@@ -827,7 +829,6 @@ pic_apply(pic_state *pic, struct pic_proc *proc, pic_value argv)
     CASE(OP_CALL) {
       pic_value x, v;
       pic_callinfo *ci;
-      struct pic_proc *proc;
 
       if (c.u.i == -1) {
         pic->sp += pic->ci[1].retc - 1;
@@ -958,7 +959,6 @@ pic_apply(pic_state *pic, struct pic_proc *proc, pic_value argv)
     CASE(OP_LAMBDA) {
       pic_value self;
       struct pic_irep *irep;
-      struct pic_proc *proc;
 
       self = pic->ci->fp[0];
       if (! pic_proc_p(self)) {

From 5cfa89ba2344cf949ba7f4614438250e60a9a3c7 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:38:58 +0900
Subject: [PATCH 08/27] starndard style initializer

---
 vm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vm.c b/vm.c
index 1eac9f91..832fb2ce 100644
--- a/vm.c
+++ b/vm.c
@@ -1094,7 +1094,7 @@ pic_value
 pic_apply_trampoline(pic_state *pic, struct pic_proc *proc, pic_value args)
 {
   static const pic_code iseq[2] = {
-    { OP_NOP, {} },
+    { OP_NOP, { .i = 0 } },
     { OP_TAILCALL, { .i = -1 } }
   };
 

From 36328c154b918d36a18c97db61690b8462ab649d Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 17:39:11 +0900
Subject: [PATCH 09/27] more fix on misc functions in vm.c

---
 vm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/vm.c b/vm.c
index 832fb2ce..7cc84d96 100644
--- a/vm.c
+++ b/vm.c
@@ -280,14 +280,14 @@ pic_get_args(pic_state *pic, const char *format, ...)
       break;
     }
     case 'c': {
-      char *c;
+      char *k;
       pic_value v;
 
-      c = va_arg(ap, char *);
+      k = va_arg(ap, char *);
       if (i < argc) {
         v = GET_OPERAND(pic,i);
         if (pic_char_p(v)) {
-          *c = pic_char(v);
+          *k = pic_char(v);
         }
         else {
           pic_errorf(pic, "pic_get_args: expected char, but got ~s", v);
@@ -488,7 +488,7 @@ vm_push_env(pic_state *pic)
 {
   pic_callinfo *ci = pic->ci;
 
-  ci->env = (struct pic_env *)pic_obj_alloc(pic, offsetof(struct pic_env, storage) + sizeof(pic_value) * ci->regc, PIC_TT_ENV);
+  ci->env = (struct pic_env *)pic_obj_alloc(pic, offsetof(struct pic_env, storage) + sizeof(pic_value) * (size_t)(ci->regc), PIC_TT_ENV);
   ci->env->up = ci->up;
   ci->env->regc = ci->regc;
   ci->env->regs = ci->regs;

From 9906865932edbaf4cddac6127bb83070bce9aef9 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 23:24:17 +0900
Subject: [PATCH 10/27] explicit int to size_t cast

---
 codegen.c | 6 +++---
 string.c  | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/codegen.c b/codegen.c
index 050f18c2..fec7ad43 100644
--- a/codegen.c
+++ b/codegen.c
@@ -1075,17 +1075,17 @@ static int
 index_local(codegen_state *state, pic_sym sym)
 {
   codegen_context *cxt = state->cxt;
-  size_t i, offset;
+  int i, offset;
   pic_sym *var;
 
   offset = 1;
-  for (i = 0; i < xv_size(&cxt->args); ++i) {
+  for (i = 0; i < (int)xv_size(&cxt->args); ++i) {
     var = xv_get(&cxt->args, i);
     if (*var == sym)
       return i + offset;
   }
   offset += i;
-  for (i = 0; i < xv_size(&cxt->locals); ++i) {
+  for (i = 0; i < (int)xv_size(&cxt->locals); ++i) {
     var = xv_get(&cxt->locals, i);
     if (*var == sym)
       return i + offset;
diff --git a/string.c b/string.c
index 2372ea31..3bad3daf 100644
--- a/string.c
+++ b/string.c
@@ -463,7 +463,7 @@ pic_str_string_to_list(pic_state *pic)
   case 1:
     start = 0;
   case 2:
-    end = pic_strlen(str);
+    end = (int)pic_strlen(str);
   }
 
   list = pic_nil_value();

From f8a32d7d60ff18b7e7851b6b40d23d3f2c64be4d Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Fri, 26 Sep 2014 23:24:26 +0900
Subject: [PATCH 11/27] use ptrdiff to extend exception handler stack

---
 error.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/error.c b/error.c
index 568e523b..0f3ac651 100644
--- a/error.c
+++ b/error.c
@@ -90,7 +90,8 @@ void
 pic_push_try(pic_state *pic, struct pic_escape *escape)
 {
   struct pic_proc *cont, *handler;
-  size_t xp_len, xp_offset;
+  size_t xp_len;
+  ptrdiff_t xp_offset;
 
   cont = pic_make_econt(pic, escape);
 
@@ -99,7 +100,7 @@ pic_push_try(pic_state *pic, struct pic_escape *escape)
   pic_attr_set(pic, pic_obj_value(handler), "@@escape", pic_obj_value(cont));
 
   if (pic->xp >= pic->xpend) {
-    xp_len = (pic->xpend - pic->xpbase) * 2;
+    xp_len = (size_t)(pic->xpend - pic->xpbase) * 2;
     xp_offset = pic->xp - pic->xpbase;
     pic->xpbase = pic_realloc(pic, pic->xpbase, sizeof(struct pic_proc *) * xp_len);
     pic->xp = pic->xpbase + xp_offset;
@@ -198,12 +199,13 @@ pic_error_with_exception_handler(pic_state *pic)
 {
   struct pic_proc *handler, *thunk;
   pic_value val;
-  size_t xp_len, xp_offset;
+  size_t xp_len;
+  ptrdiff_t xp_offset;
 
   pic_get_args(pic, "ll", &handler, &thunk);
 
   if (pic->xp >= pic->xpend) {
-    xp_len = (pic->xpend - pic->xpbase) * 2;
+    xp_len = (size_t)(pic->xpend - pic->xpbase) * 2;
     xp_offset = pic->xp - pic->xpbase;
     pic->xpbase = pic_realloc(pic, pic->xpbase, sizeof(struct pic_proc *) * xp_len);
     pic->xp = pic->xpbase + xp_offset;

From 7350f7e71e10b7813b88be1e6360bbad148bc028 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 17:18:11 +0900
Subject: [PATCH 12/27] int to size_t conversion

---
 codegen.c             | 26 +++++++++++++-------------
 include/picrin/irep.h |  4 ++--
 string.c              |  4 ++--
 symbol.c              |  2 +-
 system.c              |  2 +-
 5 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/codegen.c b/codegen.c
index fec7ad43..c4e3121e 100644
--- a/codegen.c
+++ b/codegen.c
@@ -1075,20 +1075,20 @@ static int
 index_local(codegen_state *state, pic_sym sym)
 {
   codegen_context *cxt = state->cxt;
-  int i, offset;
+  size_t i, offset;
   pic_sym *var;
 
   offset = 1;
-  for (i = 0; i < (int)xv_size(&cxt->args); ++i) {
+  for (i = 0; i < xv_size(&cxt->args); ++i) {
     var = xv_get(&cxt->args, i);
     if (*var == sym)
-      return i + offset;
+      return (int)(i + offset);
   }
   offset += i;
-  for (i = 0; i < (int)xv_size(&cxt->locals); ++i) {
+  for (i = 0; i < xv_size(&cxt->locals); ++i) {
     var = xv_get(&cxt->locals, i);
     if (*var == sym)
-      return i + offset;
+      return (int)(i + offset);
   }
   return -1;
 }
@@ -1126,7 +1126,7 @@ codegen(codegen_state *state, pic_value obj)
     name = pic_sym(pic_list_ref(pic, obj, 1));
     if ((i = index_capture(state, name, 0)) != -1) {
       cxt->code[cxt->clen].insn = OP_LREF;
-      cxt->code[cxt->clen].u.i = i + xv_size(&cxt->args) + xv_size(&cxt->locals) + 1;
+      cxt->code[cxt->clen].u.i = i + (int)xv_size(&cxt->args) + (int)xv_size(&cxt->locals) + 1;
       cxt->clen++;
       return;
     }
@@ -1172,7 +1172,7 @@ codegen(codegen_state *state, pic_value obj)
       name = pic_sym(pic_list_ref(pic, var, 1));
       if ((i = index_capture(state, name, 0)) != -1) {
         cxt->code[cxt->clen].insn = OP_LSET;
-        cxt->code[cxt->clen].u.i = i + xv_size(&cxt->args) + xv_size(&cxt->locals) + 1;
+        cxt->code[cxt->clen].u.i = i + (int)xv_size(&cxt->args) + (int)xv_size(&cxt->locals) + 1;
         cxt->clen++;
         cxt->code[cxt->clen].insn = OP_PUSHNONE;
         cxt->clen++;
@@ -1193,7 +1193,7 @@ codegen(codegen_state *state, pic_value obj)
       cxt->icapa *= 2;
       cxt->irep = pic_realloc(pic, cxt->irep, sizeof(struct pic_irep *) * cxt->icapa);
     }
-    k = cxt->ilen++;
+    k = (int)cxt->ilen++;
     cxt->code[cxt->clen].insn = OP_LAMBDA;
     cxt->code[cxt->clen].u.i = k;
     cxt->clen++;
@@ -1207,18 +1207,18 @@ codegen(codegen_state *state, pic_value obj)
     codegen(state, pic_list_ref(pic, obj, 1));
 
     cxt->code[cxt->clen].insn = OP_JMPIF;
-    s = cxt->clen++;
+    s = (int)cxt->clen++;
 
     /* if false branch */
     codegen(state, pic_list_ref(pic, obj, 3));
     cxt->code[cxt->clen].insn = OP_JMP;
-    t = cxt->clen++;
+    t = (int)cxt->clen++;
 
-    cxt->code[s].u.i = cxt->clen - s;
+    cxt->code[s].u.i = (int)cxt->clen - s;
 
     /* if true branch */
     codegen(state, pic_list_ref(pic, obj, 2));
-    cxt->code[t].u.i = cxt->clen - t;
+    cxt->code[t].u.i = (int)cxt->clen - t;
     return;
   }
   else if (sym == pic->sBEGIN) {
@@ -1266,7 +1266,7 @@ codegen(codegen_state *state, pic_value obj)
         cxt->pcapa *= 2;
         cxt->pool = pic_realloc(pic, cxt->pool, sizeof(pic_value) * cxt->pcapa);
       }
-      pidx = cxt->plen++;
+      pidx = (int)cxt->plen++;
       cxt->pool[pidx] = obj;
       cxt->code[cxt->clen].insn = OP_PUSHCONST;
       cxt->code[cxt->clen].u.i = pidx;
diff --git a/include/picrin/irep.h b/include/picrin/irep.h
index c6e5befb..fe924bbc 100644
--- a/include/picrin/irep.h
+++ b/include/picrin/irep.h
@@ -52,8 +52,8 @@ struct pic_code {
     int i;
     char c;
     struct {
-      short depth;
-      short idx;
+      int depth;
+      int idx;
     } r;
   } u;
 };
diff --git a/string.c b/string.c
index 3bad3daf..7f03cfae 100644
--- a/string.c
+++ b/string.c
@@ -240,14 +240,14 @@ pic_str_string(pic_state *pic)
 
   pic_get_args(pic, "*", &argc, &argv);
 
-  buf = pic_alloc(pic, argc);
+  buf = pic_alloc(pic, (size_t)argc);
 
   for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], char);
     buf[i] = pic_char(argv[i]);
   }
 
-  str = pic_make_str(pic, buf, argc);
+  str = pic_make_str(pic, buf, (size_t)argc);
   pic_free(pic, buf);
 
   return pic_obj_value(str);
diff --git a/symbol.c b/symbol.c
index d6feab13..7e9f1b52 100644
--- a/symbol.c
+++ b/symbol.c
@@ -80,7 +80,7 @@ pic_ungensym(pic_state *pic, pic_sym base)
   if ((occr = strrchr(name, '@')) == NULL) {
     pic_panic(pic, "logic flaw");
   }
-  return pic_intern(pic, name, occr - name);
+  return pic_intern(pic, name, (size_t)(occr - name));
 }
 
 bool
diff --git a/system.c b/system.c
index 4c54b905..e9ef1aa9 100644
--- a/system.c
+++ b/system.c
@@ -110,7 +110,7 @@ pic_system_getenvs(pic_state *pic)
     for (i = 0; (*envp)[i] != '='; ++i)
       ;
 
-    key = pic_make_str(pic, *envp, i);
+    key = pic_make_str(pic, *envp, (size_t)i);
     val = pic_make_str_cstr(pic, getenv(pic_str_cstr(key)));
 
     /* push */

From 186bad0503977d9cdf1e4533812986166288fc3f Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 17:19:16 +0900
Subject: [PATCH 13/27] pair functions must use size_t for index, not int

---
 include/picrin/pair.h | 10 +++++-----
 pair.c                | 14 +++++++-------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/picrin/pair.h b/include/picrin/pair.h
index 49e3f73f..d6cf779d 100644
--- a/include/picrin/pair.h
+++ b/include/picrin/pair.h
@@ -57,7 +57,7 @@ pic_value pic_list5(pic_state *, pic_value, pic_value, pic_value, pic_value, pic
 pic_value pic_list6(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list7(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list_by_array(pic_state *, int, pic_value *);
-pic_value pic_make_list(pic_state *, int, pic_value);
+pic_value pic_make_list(pic_state *, size_t, pic_value);
 
 #define pic_for_each(var, list)                                 \
   pic_for_each_helper_(var, GENSYM(tmp), list)
@@ -69,7 +69,7 @@ pic_value pic_make_list(pic_state *, int, pic_value);
 #define pic_push(pic, item, place) (place = pic_cons(pic, item, place))
 #define pic_pop(pic, place) (place = pic_cdr(pic, place))
 
-int pic_length(pic_state *, pic_value);
+size_t pic_length(pic_state *, pic_value);
 pic_value pic_reverse(pic_state *, pic_value);
 pic_value pic_append(pic_state *, pic_value, pic_value);
 
@@ -88,9 +88,9 @@ pic_value pic_cadr(pic_state *, pic_value);
 pic_value pic_cdar(pic_state *, pic_value);
 pic_value pic_cddr(pic_state *, pic_value);
 
-pic_value pic_list_tail(pic_state *, pic_value, int);
-pic_value pic_list_ref(pic_state *, pic_value, int);
-void pic_list_set(pic_state *, pic_value, int, pic_value);
+pic_value pic_list_tail(pic_state *, pic_value, size_t);
+pic_value pic_list_ref(pic_state *, pic_value, size_t);
+void pic_list_set(pic_state *, pic_value, size_t, pic_value);
 pic_value pic_list_copy(pic_state *, pic_value);
 
 #if defined(__cplusplus)
diff --git a/pair.c b/pair.c
index 6a9687d8..c2a775dc 100644
--- a/pair.c
+++ b/pair.c
@@ -172,10 +172,10 @@ pic_list_by_array(pic_state *pic, int c, pic_value *vs)
 }
 
 pic_value
-pic_make_list(pic_state *pic, int k, pic_value fill)
+pic_make_list(pic_state *pic, size_t k, pic_value fill)
 {
   pic_value list;
-  int i;
+  size_t i;
 
   list = pic_nil_value();
   for (i = 0; i < k; ++i) {
@@ -185,10 +185,10 @@ pic_make_list(pic_state *pic, int k, pic_value fill)
   return list;
 }
 
-int
+size_t
 pic_length(pic_state *pic, pic_value obj)
 {
-  int c = 0;
+  size_t c = 0;
 
   if (! pic_list_p(obj)) {
     pic_errorf(pic, "length: expected list, but got ~s", obj);
@@ -375,7 +375,7 @@ pic_cddr(pic_state *pic, pic_value v)
 }
 
 pic_value
-pic_list_tail(pic_state *pic, pic_value list, int i)
+pic_list_tail(pic_state *pic, pic_value list, size_t i)
 {
   while (i-- > 0) {
     list = pic_cdr(pic, list);
@@ -384,13 +384,13 @@ pic_list_tail(pic_state *pic, pic_value list, int i)
 }
 
 pic_value
-pic_list_ref(pic_state *pic, pic_value list, int i)
+pic_list_ref(pic_state *pic, pic_value list, size_t i)
 {
   return pic_car(pic, pic_list_tail(pic, list, i));
 }
 
 void
-pic_list_set(pic_state *pic, pic_value list, int i, pic_value obj)
+pic_list_set(pic_state *pic, pic_value list, size_t i, pic_value obj)
 {
   pic_pair_ptr(pic_list_tail(pic, list, i))->car = obj;
 }

From 4ac6c2b7ab6a6b813d5f1d2712ba6a496b6f4cc3 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 17:33:49 +0900
Subject: [PATCH 14/27] refine description of pic_get_args

---
 vm.c | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/vm.c b/vm.c
index 7cc84d96..7599c919 100644
--- a/vm.c
+++ b/vm.c
@@ -35,26 +35,26 @@ pic_get_proc(pic_state *pic)
 }
 
 /**
- * char type
- * ---- ----
- *  o   object
- *  i   int
- *  I   int with exactness
- *  f   float
- *  F   float with exactness
- *  s   string object
- *  z   c string
- *  m   symbol
- *  v   vector object
- *  b   bytevector object
- *  c   char
- *  l   lambda object
- *  p   port object
- *  d   dictionary object
- *  e   error object
+ * char type                 desc.
+ * ---- ----                 ----
+ *  o   pic_value *          object
+ *  i   int *                int
+ *  I   int *, bool *        int with exactness
+ *  f   double *             float
+ *  F   double *, bool *     float with exactness
+ *  s   pic_str **           string object
+ *  z   char **              c string
+ *  m   pic_sym *            symbol
+ *  v   pic_vec **           vector object
+ *  b   pic_blob **          bytevector object
+ *  c   char *               char
+ *  l   struct pic_proc **   lambda object
+ *  p   struct pic_port **   port object
+ *  d   struct pic_dict **   dictionary object
+ *  e   struct pic_error **  error object
  *
- *  |  optional operator
- *  *  variable length operator
+ *  |                        optional operator
+ *  *   int *, pic_value **  variable length operator
  */
 
 int

From bfc45a228ba166416f97e6355c2c7147757f9ab7 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 17:47:47 +0900
Subject: [PATCH 15/27] add 'k' specifier to pic_get_args format

---
 vm.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/vm.c b/vm.c
index 7599c919..97e21bf6 100644
--- a/vm.c
+++ b/vm.c
@@ -40,6 +40,7 @@ pic_get_proc(pic_state *pic)
  *  o   pic_value *          object
  *  i   int *                int
  *  I   int *, bool *        int with exactness
+ *  k   size_t *             size_t implicitly converted from int
  *  f   double *             float
  *  F   double *, bool *     float with exactness
  *  s   pic_str **           string object
@@ -196,6 +197,33 @@ pic_get_args(pic_state *pic, const char *format, ...)
       }
       break;
     }
+    case 'k': {
+      size_t *k;
+
+      k = va_arg(ap, size_t *);
+      if (i < argc) {
+        pic_value v;
+        int x;
+
+        v = GET_OPERAND(pic, i);
+        switch (pic_type(v)) {
+        case PIC_TT_INT:
+          x = pic_int(v);
+          if (x < 0) {
+            pic_errorf(pic, "pic_get_args: expected non-negative int, but got ~s", v);
+          }
+          if (sizeof(unsigned) > sizeof(size_t) && (unsigned)x > (unsigned)SIZE_MAX) {
+            pic_errorf(pic, "pic_get_args: int unrepresentable with size_t ~s", v);
+          }
+          *k = (size_t)x;
+          break;
+        default:
+          pic_errorf(pic, "pic_get_args: expected int, but got ~s", v);
+        }
+        i++;
+      }
+      break;
+    }
     case 's': {
       pic_str **str;
       pic_value v;

From 8bdf6230546644b89a94722a8ac2d5154730e2e5 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 17:52:56 +0900
Subject: [PATCH 16/27] use k format specifier in blob.c

---
 blob.c | 42 +++++++++++++++++++++---------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/blob.c b/blob.c
index da3907c3..509b295a 100644
--- a/blob.c
+++ b/blob.c
@@ -60,17 +60,15 @@ static pic_value
 pic_blob_make_bytevector(pic_state *pic)
 {
   pic_blob *blob;
-  int k, b = 0, i;
+  size_t k, i;
+  int b = 0;
 
-  pic_get_args(pic, "i|i", &k, &b);
+  pic_get_args(pic, "k|i", &k, &b);
 
   if (b < 0 || b > 255)
     pic_errorf(pic, "byte out of range");
 
-  if (k < 0)
-    pic_errorf(pic, "make-bytevector: cannot create a bytevector of length %d", k);
-
-  blob = pic_make_blob(pic, (size_t)k);
+  blob = pic_make_blob(pic, k);
   for (i = 0; i < k; ++i) {
     blob->data[i] = (unsigned char)b;
   }
@@ -118,15 +116,16 @@ static pic_value
 pic_blob_bytevector_copy_i(pic_state *pic)
 {
   pic_blob *to, *from;
-  int n, at, start, end;
+  int n;
+  size_t at, start, end;
 
-  n = pic_get_args(pic, "bib|ii", &to, &at, &from, &start, &end);
+  n = pic_get_args(pic, "bkb|kk", &to, &at, &from, &start, &end);
 
   switch (n) {
   case 3:
     start = 0;
   case 4:
-    end = (int)from->len;
+    end = from->len;
   }
 
   if (to == from && (start <= at && at < end)) {
@@ -149,23 +148,23 @@ static pic_value
 pic_blob_bytevector_copy(pic_state *pic)
 {
   pic_blob *from, *to;
-  int n, start, end, k, i = 0;
+  int n;
+  size_t start, end, i = 0;
 
-  n = pic_get_args(pic, "b|ii", &from, &start, &end);
+  n = pic_get_args(pic, "b|kk", &from, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)from->len;
+    end = from->len;
   }
 
-  k = end - start;
+  if (end < start) {
+    pic_errorf(pic, "make-bytevector: end index must not be less than start index");
+  }
 
-  if (k < 0)
-    pic_errorf(pic, "make-bytevector: cannot create a bytevector of length %d", k);
-
-  to = pic_make_blob(pic, (size_t)k);
+  to = pic_make_blob(pic, end - start);
   while (start < end) {
     to->data[i++] = from->data[start++];
   }
@@ -211,7 +210,7 @@ pic_blob_list_to_bytevector(pic_state *pic)
 
   pic_get_args(pic, "o", &list);
 
-  blob = pic_make_blob(pic, (size_t)pic_length(pic, list));
+  blob = pic_make_blob(pic, pic_length(pic, list));
 
   data = blob->data;
 
@@ -231,15 +230,16 @@ pic_blob_bytevector_to_list(pic_state *pic)
 {
   pic_blob *blob;
   pic_value list;
-  int n, start, end, i;
+  int n;
+  size_t start, end, i;
 
-  n = pic_get_args(pic, "b|ii", &blob, &start, &end);
+  n = pic_get_args(pic, "b|kk", &blob, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)blob->len;
+    end = blob->len;
   }
 
   list = pic_nil_value();

From d34cbccf12062d0279df192a36f12a39c89321a2 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 18:10:14 +0900
Subject: [PATCH 17/27] use k format specifier in vector.c

---
 vector.c | 95 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 47 insertions(+), 48 deletions(-)

diff --git a/vector.c b/vector.c
index ba0dc7c8..86cd3c9b 100644
--- a/vector.c
+++ b/vector.c
@@ -26,11 +26,11 @@ struct pic_vector *
 pic_make_vec_from_list(pic_state *pic, pic_value data)
 {
   struct pic_vector *vec;
-  int len, i;
+  size_t len, i;
 
   len = pic_length(pic, data);
 
-  vec = pic_make_vec(pic, (size_t)len);
+  vec = pic_make_vec(pic, len);
   for (i = 0; i < len; ++i) {
     vec->data[i] = pic_car(pic, data);
     data = pic_cdr(pic, data);
@@ -70,19 +70,15 @@ static pic_value
 pic_vec_make_vector(pic_state *pic)
 {
   pic_value v;
-  int n, k;
-  size_t i;
+  int n;
+  size_t k, i;
   struct pic_vector *vec;
 
-  n = pic_get_args(pic, "i|o", &k, &v);
+  n = pic_get_args(pic, "k|o", &k, &v);
 
-  if (k < 0) {
-    pic_errorf(pic, "make-vector: vector length must be non-negative");
-  }
-
-  vec = pic_make_vec(pic, (size_t)k);
+  vec = pic_make_vec(pic, k);
   if (n == 2) {
-    for (i = 0; i < (size_t)k; ++i) {
+    for (i = 0; i < k; ++i) {
       vec->data[i] = v;
     }
   }
@@ -103,11 +99,11 @@ static pic_value
 pic_vec_vector_ref(pic_state *pic)
 {
   struct pic_vector *v;
-  int k;
+  size_t k;
 
-  pic_get_args(pic, "vi", &v, &k);
+  pic_get_args(pic, "vk", &v, &k);
 
-  if (k < 0 || v->len <= (size_t)k) {
+  if (v->len <= k) {
     pic_errorf(pic, "vector-ref: index out of range");
   }
   return v->data[k];
@@ -117,12 +113,12 @@ static pic_value
 pic_vec_vector_set(pic_state *pic)
 {
   struct pic_vector *v;
-  int k;
+  size_t k;
   pic_value o;
 
-  pic_get_args(pic, "vio", &v, &k, &o);
+  pic_get_args(pic, "vko", &v, &k, &o);
 
-  if (k < 0 || v->len <= (size_t)k) {
+  if (v->len <= k) {
     pic_errorf(pic, "vector-set!: index out of range");
   }
   v->data[k] = o;
@@ -133,15 +129,16 @@ static pic_value
 pic_vec_vector_copy_i(pic_state *pic)
 {
   pic_vec *to, *from;
-  int n, at, start, end;
+  int n;
+  size_t at, start, end;
 
-  n = pic_get_args(pic, "viv|ii", &to, &at, &from, &start, &end);
+  n = pic_get_args(pic, "vkv|kk", &to, &at, &from, &start, &end);
 
   switch (n) {
   case 3:
     start = 0;
   case 4:
-    end = (int)from->len;
+    end = from->len;
   }
 
   if (to == from && (start <= at && at < end)) {
@@ -164,22 +161,23 @@ static pic_value
 pic_vec_vector_copy(pic_state *pic)
 {
   pic_vec *vec, *to;
-  int n, start, end, i = 0;
+  int n;
+  size_t start, end, i = 0;
 
-  n = pic_get_args(pic, "v|ii", &vec, &start, &end);
+  n = pic_get_args(pic, "v|kk", &vec, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)vec->len;
+    end = vec->len;
   }
 
-  if (end - start < 0) {
+  if (end < start) {
     pic_errorf(pic, "vector-copy: end index must not be less than start index");
   }
 
-  to = pic_make_vec(pic, (size_t)(end - start));
+  to = pic_make_vec(pic, end - start);
   while (start < end) {
     to->data[i++] = vec->data[start++];
   }
@@ -221,15 +219,16 @@ pic_vec_vector_fill_i(pic_state *pic)
 {
   pic_vec *vec;
   pic_value obj;
-  int n, start, end;
+  int n;
+  size_t start, end;
 
-  n = pic_get_args(pic, "vo|ii", &vec, &obj, &start, &end);
+  n = pic_get_args(pic, "vo|kk", &vec, &obj, &start, &end);
 
   switch (n) {
   case 2:
     start = 0;
   case 3:
-    end = (int)vec->len;
+    end = vec->len;
   }
 
   while (start < end) {
@@ -310,7 +309,7 @@ pic_vec_list_to_vector(pic_state *pic)
 
   pic_get_args(pic, "o", &list);
 
-  vec = pic_make_vec(pic, (size_t)pic_length(pic, list));
+  vec = pic_make_vec(pic, pic_length(pic, list));
 
   data = vec->data;
 
@@ -325,15 +324,16 @@ pic_vec_vector_to_list(pic_state *pic)
 {
   struct pic_vector *vec;
   pic_value list;
-  int n, start, end, i;
+  int n;
+  size_t start, end, i;
 
-  n = pic_get_args(pic, "v|ii", &vec, &start, &end);
+  n = pic_get_args(pic, "v|kk", &vec, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)vec->len;
+    end = vec->len;
   }
 
   list = pic_nil_value();
@@ -349,23 +349,24 @@ pic_vec_vector_to_string(pic_state *pic)
 {
   pic_vec *vec;
   char *buf;
-  int n, start, end, i;
+  int n;
+  size_t start, end, i;
   pic_str *str;
 
-  n = pic_get_args(pic, "v|ii", &vec, &start, &end);
+  n = pic_get_args(pic, "v|kk", &vec, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)vec->len;
+    end = vec->len;
   }
 
-  if (end - start < 0) {
+  if (end < start) {
     pic_errorf(pic, "vector->string: end index must not be less than start index");
   }
 
-  buf = pic_alloc(pic, (size_t)(end - start));
+  buf = pic_alloc(pic, end - start);
 
   for (i = start; i < end; ++i) {
     pic_assert_type(pic, vec->data[i], char);
@@ -373,7 +374,7 @@ pic_vec_vector_to_string(pic_state *pic)
     buf[i - start] = pic_char(vec->data[i]);
   }
 
-  str = pic_make_str(pic, buf, (size_t)(end - start));
+  str = pic_make_str(pic, buf, end - start);
   pic_free(pic, buf);
 
   return pic_obj_value(str);
@@ -383,30 +384,28 @@ static pic_value
 pic_vec_string_to_vector(pic_state *pic)
 {
   pic_str *str;
-  int n, start, end;
+  int n;
+  size_t start, end;
   size_t i;
   pic_vec *vec;
 
-  n = pic_get_args(pic, "s|ii", &str, &start, &end);
+  n = pic_get_args(pic, "s|kk", &str, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)pic_strlen(str);
+    end = pic_strlen(str);
   }
 
-  if (start < 0) {
-    pic_errorf(pic, "string->vector: index must non-negative");
-  }
-  if (end - start < 0) {
+  if (end < start) {
     pic_errorf(pic, "string->vector: end index must not be less than start index");
   }
 
-  vec = pic_make_vec(pic, (size_t)(end - start));
+  vec = pic_make_vec(pic, end - start);
 
-  for (i = 0; i < (size_t)(end - start); ++i) {
-    vec->data[i] = pic_char_value(pic_str_ref(pic, str, i + (size_t)start));
+  for (i = 0; i < end - start; ++i) {
+    vec->data[i] = pic_char_value(pic_str_ref(pic, str, i + start));
   }
   return pic_obj_value(vec);
 }

From de51c221348b1e6673719baa91242f69a3688413 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 18:16:27 +0900
Subject: [PATCH 18/27] use k format specifier in pair.c

---
 pair.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/pair.c b/pair.c
index c2a775dc..763458f9 100644
--- a/pair.c
+++ b/pair.c
@@ -533,10 +533,10 @@ pic_pair_list_p(pic_state *pic)
 static pic_value
 pic_pair_make_list(pic_state *pic)
 {
-  int i;
+  size_t i;
   pic_value fill = pic_none_value();
 
-  pic_get_args(pic, "i|o", &i, &fill);
+  pic_get_args(pic, "k|o", &i, &fill);
 
   return pic_make_list(pic, i, fill);
 }
@@ -596,9 +596,9 @@ static pic_value
 pic_pair_list_tail(pic_state *pic)
 {
   pic_value list;
-  int i;
+  size_t i;
 
-  pic_get_args(pic, "oi", &list, &i);
+  pic_get_args(pic, "ok", &list, &i);
 
   return pic_list_tail(pic, list, i);
 }
@@ -607,9 +607,9 @@ static pic_value
 pic_pair_list_ref(pic_state *pic)
 {
   pic_value list;
-  int i;
+  size_t i;
 
-  pic_get_args(pic, "oi", &list, &i);
+  pic_get_args(pic, "ok", &list, &i);
 
   return pic_list_ref(pic, list, i);
 }
@@ -618,9 +618,9 @@ static pic_value
 pic_pair_list_set(pic_state *pic)
 {
   pic_value list, obj;
-  int i;
+  size_t i;
 
-  pic_get_args(pic, "oio", &list, &i, &obj);
+  pic_get_args(pic, "oko", &list, &i, &obj);
 
   pic_list_set(pic, list, i, obj);
 

From b3def908b6ac15eca0dee2721d9268a664ef16b9 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 18:48:20 +0900
Subject: [PATCH 19/27] use k format specifier in string.c

---
 string.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/string.c b/string.c
index 7f03cfae..6ef7e745 100644
--- a/string.c
+++ b/string.c
@@ -256,10 +256,10 @@ pic_str_string(pic_state *pic)
 static pic_value
 pic_str_make_string(pic_state *pic)
 {
-  int len;
+  size_t len;
   char c = ' ';
 
-  pic_get_args(pic, "i|c", &len, &c);
+  pic_get_args(pic, "k|c", &len, &c);
 
   return pic_obj_value(pic_make_str_fill(pic, len, c));
 }
@@ -278,9 +278,9 @@ static pic_value
 pic_str_string_ref(pic_state *pic)
 {
   pic_str *str;
-  int k;
+  size_t k;
 
-  pic_get_args(pic, "si", &str, &k);
+  pic_get_args(pic, "sk", &str, &k);
 
   return pic_char_value(pic_str_ref(pic, str, k));
 }
@@ -319,9 +319,10 @@ static pic_value
 pic_str_string_copy(pic_state *pic)
 {
   pic_str *str;
-  int n, start, end;
+  int n;
+  size_t start, end;
 
-  n = pic_get_args(pic, "s|ii", &str, &start, &end);
+  n = pic_get_args(pic, "s|kk", &str, &start, &end);
 
   switch (n) {
   case 1:
@@ -356,14 +357,14 @@ static pic_value
 pic_str_string_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i;
+  int argc;
   pic_value *argv, vals, val;
-  size_t len, j;
+  size_t i, len, j;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = SIZE_MAX;
-  for (i = 0; i < argc; ++i) {
+  for (i = 0; i < (size_t)argc; ++i) {
     pic_assert_type(pic, argv[i], str);
 
     len = len < pic_strlen(pic_str_ptr(argv[i]))
@@ -378,7 +379,7 @@ pic_str_string_map(pic_state *pic)
 
     for (i = 0; i < len; ++i) {
       vals = pic_nil_value();
-      for (j = 0; j < argc; ++j) {
+      for (j = 0; j < (size_t)argc; ++j) {
         pic_push(pic, pic_char_value(pic_str_ref(pic, pic_str_ptr(argv[j]), i)), vals);
       }
       val = pic_apply(pic, proc, vals);
@@ -395,14 +396,14 @@ static pic_value
 pic_str_string_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i;
-  size_t len, j;
+  int argc;
+  size_t len, i, j;
   pic_value *argv, vals, val;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = SIZE_MAX;
-  for (i = 0; i < argc; ++i) {
+  for (i = 0; i < (size_t)argc; ++i) {
     pic_assert_type(pic, argv[i], str);
 
     len = len < pic_strlen(pic_str_ptr(argv[i]))
@@ -415,7 +416,7 @@ pic_str_string_for_each(pic_state *pic)
 
   for (i = 0; i < len; ++i) {
     vals = pic_nil_value();
-    for (j = 0; j < argc; ++j) {
+    for (j = 0; j < (size_t)argc; ++j) {
       pic_push(pic, pic_char_value(pic_str_ref(pic, pic_str_ptr(argv[j]), i)), vals);
     }
     val = pic_apply(pic, proc, vals);
@@ -429,7 +430,7 @@ pic_str_list_to_string(pic_state *pic)
 {
   pic_str *str;
   pic_value list, e;
-  int i = 0;
+  size_t i = 0;
 
   pic_get_args(pic, "o", &list);
 
@@ -455,15 +456,16 @@ pic_str_string_to_list(pic_state *pic)
 {
   pic_str *str;
   pic_value list;
-  int n, start, end, i;
+  int n;
+  size_t start, end, i;
 
-  n = pic_get_args(pic, "s|ii", &str, &start, &end);
+  n = pic_get_args(pic, "s|kk", &str, &start, &end);
 
   switch (n) {
   case 1:
     start = 0;
   case 2:
-    end = (int)pic_strlen(str);
+    end = pic_strlen(str);
   }
 
   list = pic_nil_value();

From cf9d48a8653cb2dfb2826eca1cc4423de01849e9 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 19:40:10 +0900
Subject: [PATCH 20/27] add pic_size_value

---
 blob.c                 |  2 +-
 dict.c                 |  2 +-
 include/picrin/value.h | 12 ++++++++++++
 pair.c                 |  2 +-
 string.c               |  2 +-
 vector.c               |  2 +-
 6 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/blob.c b/blob.c
index 509b295a..ae0f2fb7 100644
--- a/blob.c
+++ b/blob.c
@@ -83,7 +83,7 @@ pic_blob_bytevector_length(pic_state *pic)
 
   pic_get_args(pic, "b", &bv);
 
-  return pic_int_value((int)bv->len);
+  return pic_size_value(bv->len);
 }
 
 static pic_value
diff --git a/dict.c b/dict.c
index 2a8fcd41..c5387706 100644
--- a/dict.c
+++ b/dict.c
@@ -213,7 +213,7 @@ pic_dict_dictionary_size(pic_state *pic)
 
   pic_get_args(pic, "d", &dict);
 
-  return pic_int_value((int)pic_dict_size(pic, dict));
+  return pic_size_value(pic_dict_size(pic, dict));
 }
 
 static pic_value
diff --git a/include/picrin/value.h b/include/picrin/value.h
index 37dd58c0..d0c1dbe3 100644
--- a/include/picrin/value.h
+++ b/include/picrin/value.h
@@ -189,6 +189,7 @@ static inline pic_value pic_undef_value();
 static inline pic_value pic_obj_value(void *);
 static inline pic_value pic_float_value(double);
 static inline pic_value pic_int_value(int);
+static inline pic_value pic_size_value(size_t);
 static inline pic_value pic_sym_value(pic_sym);
 static inline pic_value pic_char_value(char c);
 static inline pic_value pic_none_value();
@@ -323,6 +324,17 @@ pic_bool_value(bool b)
   return v;
 }
 
+static inline pic_value
+pic_size_value(size_t s)
+{
+  if (sizeof(unsigned) < sizeof(size_t)) {
+    if (s > (size_t)INT_MAX) {
+      return pic_float_value(s);
+    }
+  }
+  return pic_int_value((int)s);
+}
+
 #if PIC_NAN_BOXING
 
 static inline pic_value
diff --git a/pair.c b/pair.c
index 763458f9..184182cc 100644
--- a/pair.c
+++ b/pair.c
@@ -559,7 +559,7 @@ pic_pair_length(pic_state *pic)
 
   pic_get_args(pic, "o", &list);
 
-  return pic_int_value(pic_length(pic, list));
+  return pic_size_value(pic_length(pic, list));
 }
 
 static pic_value
diff --git a/string.c b/string.c
index 6ef7e745..cd4b3660 100644
--- a/string.c
+++ b/string.c
@@ -271,7 +271,7 @@ pic_str_string_length(pic_state *pic)
 
   pic_get_args(pic, "s", &str);
 
-  return pic_int_value(pic_strlen(str));
+  return pic_size_value(pic_strlen(str));
 }
 
 static pic_value
diff --git a/vector.c b/vector.c
index 86cd3c9b..a7dbd81d 100644
--- a/vector.c
+++ b/vector.c
@@ -92,7 +92,7 @@ pic_vec_vector_length(pic_state *pic)
 
   pic_get_args(pic, "v", &v);
 
-  return pic_int_value((int)v->len);
+  return pic_size_value(v->len);
 }
 
 static pic_value

From 7f68fd3e2a6938c6633fc200605b17ce4d019b83 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 19:48:58 +0900
Subject: [PATCH 21/27] use k format specifier in port.c

---
 port.c | 34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/port.c b/port.c
index 5cbcb1b8..ec61d984 100644
--- a/port.c
+++ b/port.c
@@ -521,20 +521,15 @@ pic_port_read_blob(pic_state *pic)
 {
   struct pic_port *port = pic_stdin(pic);
   pic_blob *blob;
-  int k;
-  size_t i;
+  size_t k, i;
 
-  pic_get_args(pic, "i|p", &k, &port);
+  pic_get_args(pic, "k|p", &k, &port);
 
   assert_port_profile(port, PIC_PORT_IN | PIC_PORT_BINARY, PIC_PORT_OPEN, "read-bytevector");
 
-  if (k < 0) {
-    pic_errorf(pic, "read-bytevector: index must be non-negative %d", k);
-  }
+  blob = pic_make_blob(pic, k);
 
-  blob = pic_make_blob(pic, (size_t)k);
-
-  i = xfread(blob->data, sizeof(char), (size_t)k, port->file);
+  i = xfread(blob->data, sizeof(char), k, port->file);
   if (i == 0) {
     return pic_eof_object();
   }
@@ -550,27 +545,27 @@ pic_port_read_blob_ip(pic_state *pic)
 {
   struct pic_port *port;
   struct pic_blob *bv;
-  int n, start, end;
+  int n;
   char *buf;
-  size_t i, len;
+  size_t start, end, i, len;
 
-  n = pic_get_args(pic, "b|pii", &bv, &port, &start, &end);
+  n = pic_get_args(pic, "b|pkk", &bv, &port, &start, &end);
   switch (n) {
   case 1:
     port = pic_stdin(pic);
   case 2:
     start = 0;
   case 3:
-    end = (int)bv->len;
+    end = bv->len;
   }
 
   assert_port_profile(port, PIC_PORT_IN | PIC_PORT_BINARY, PIC_PORT_OPEN, "read-bytevector!");
 
-  if (end - start < 0) {
+  if (end < start) {
     pic_errorf(pic, "read-bytevector!: end index must be greater than or equal to start index");
   }
 
-  len = (size_t)(end - start);
+  len = end - start;
 
   buf = pic_calloc(pic, len, sizeof(char));
   i = xfread(buf, sizeof(char), len, port->file);
@@ -581,7 +576,7 @@ pic_port_read_blob_ip(pic_state *pic)
     return pic_eof_object();
   }
   else {
-    return pic_int_value((int)i);
+    return pic_size_value(i);
   }
 }
 
@@ -656,16 +651,17 @@ pic_port_write_blob(pic_state *pic)
 {
   struct pic_blob *blob;
   struct pic_port *port;
-  int start, end, n, i;
+  int n;
+  size_t start, end, i;
 
-  n = pic_get_args(pic, "b|pii", &blob, &port, &start, &end);
+  n = pic_get_args(pic, "b|pkk", &blob, &port, &start, &end);
   switch (n) {
   case 1:
     port = pic_stdout(pic);
   case 2:
     start = 0;
   case 3:
-    end = (int)blob->len;
+    end = blob->len;
   }
 
   assert_port_profile(port, PIC_PORT_OUT | PIC_PORT_BINARY, PIC_PORT_OPEN, "write-bytevector");

From d165b6ea6fbe995b7fb5c68023a32a290ff9344c Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 19:49:32 +0900
Subject: [PATCH 22/27] avoid explicit casts if possible (small refacotring on
 dict.c, system.c)

---
 dict.c   | 10 ++++++----
 system.c |  4 ++--
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/dict.c b/dict.c
index c5387706..890af074 100644
--- a/dict.c
+++ b/dict.c
@@ -12,11 +12,13 @@ xh_value_hash(const void *key, void *data)
 {
   union { double f; int i; } u;
   pic_value val = *(pic_value *)key;
-  int hash;
+  int hash, vtype;
 
   UNUSED(data);
 
-  switch (pic_vtype(val)) {
+  vtype = pic_vtype(val);
+
+  switch (vtype) {
   default:
     hash = 0;
     break;
@@ -31,11 +33,11 @@ xh_value_hash(const void *key, void *data)
     hash = pic_int(val);
     break;
   case PIC_VTYPE_HEAP:
-    hash = (int)pic_ptr(val);
+    hash = (int)(intptr_t)pic_ptr(val);
     break;
   }
 
-  return hash + (int)pic_vtype(val);
+  return hash + vtype;
 }
 
 static int
diff --git a/system.c b/system.c
index e9ef1aa9..1b251661 100644
--- a/system.c
+++ b/system.c
@@ -105,12 +105,12 @@ pic_system_getenvs(pic_state *pic)
 
   for (envp = pic->envp; *envp; ++envp) {
     pic_str *key, *val;
-    int i;
+    size_t i;
 
     for (i = 0; (*envp)[i] != '='; ++i)
       ;
 
-    key = pic_make_str(pic, *envp, (size_t)i);
+    key = pic_make_str(pic, *envp, i);
     val = pic_make_str_cstr(pic, getenv(pic_str_cstr(key)));
 
     /* push */

From 552ee7444fc6e1519a84eb5d8cc5cbc6ae15cf91 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 19:58:04 +0900
Subject: [PATCH 23/27] more fix

---
 codegen.c |  4 ++--
 time.c    |  2 +-
 vm.c      | 10 ++++++----
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/codegen.c b/codegen.c
index c4e3121e..f6183278 100644
--- a/codegen.c
+++ b/codegen.c
@@ -1375,7 +1375,7 @@ codegen(codegen_state *state, pic_value obj)
     return;
   }
   else if (sym == state->sCALL || sym == state->sTAILCALL) {
-    int len = pic_length(pic, obj);
+    int len = (int)pic_length(pic, obj);
     pic_value elt;
 
     pic_for_each (elt, pic_cdr(pic, obj)) {
@@ -1401,7 +1401,7 @@ codegen(codegen_state *state, pic_value obj)
     return;
   }
   else if (sym == state->sRETURN) {
-    int len = pic_length(pic, obj);
+    int len = (int)pic_length(pic, obj);
     pic_value elt;
 
     pic_for_each (elt, pic_cdr(pic, obj)) {
diff --git a/time.c b/time.c
index a0a1ffb6..83716db8 100644
--- a/time.c
+++ b/time.c
@@ -27,7 +27,7 @@ pic_current_jiffy(pic_state *pic)
   pic_get_args(pic, "");
 
   c = clock();
-  return pic_int_value((int)c);
+  return pic_int_value((int)c); /* The year 2038 problem :-| */
 }
 
 static pic_value
diff --git a/vm.c b/vm.c
index 97e21bf6..fbdd6c2b 100644
--- a/vm.c
+++ b/vm.c
@@ -212,8 +212,10 @@ pic_get_args(pic_state *pic, const char *format, ...)
           if (x < 0) {
             pic_errorf(pic, "pic_get_args: expected non-negative int, but got ~s", v);
           }
-          if (sizeof(unsigned) > sizeof(size_t) && (unsigned)x > (unsigned)SIZE_MAX) {
-            pic_errorf(pic, "pic_get_args: int unrepresentable with size_t ~s", v);
+          if (sizeof(unsigned) > sizeof(size_t)) {
+            if ((unsigned)x > (unsigned)SIZE_MAX) {
+              pic_errorf(pic, "pic_get_args: int unrepresentable with size_t ~s", v);
+            }
           }
           *k = (size_t)x;
           break;
@@ -707,7 +709,7 @@ pic_apply(pic_state *pic, struct pic_proc *proc, pic_value args)
   else {
     int argc, i;
 
-    argc = pic_length(pic, args) + 1;
+    argc = (int)pic_length(pic, args) + 1;
 
     VM_BOOT_PRINT;
 
@@ -1139,7 +1141,7 @@ pic_apply_trampoline(pic_state *pic, struct pic_proc *proc, pic_value args)
   ci = PUSHCI();
   ci->ip = (pic_code *)iseq;
   ci->fp = pic->sp;
-  ci->retc = pic_length(pic, args);
+  ci->retc = (int)pic_length(pic, args);
 
   if (ci->retc == 0) {
     return pic_none_value();

From c808b34a677815886f784c4c89d4fbf821d9f397 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 20:15:47 +0900
Subject: [PATCH 24/27] refactor map and for-each

---
 pair.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/pair.c b/pair.c
index 184182cc..cbb4de70 100644
--- a/pair.c
+++ b/pair.c
@@ -643,23 +643,24 @@ pic_pair_map(pic_state *pic)
   struct pic_proc *proc;
   int argc, i;
   pic_value *args;
-  pic_value cars, ret;
+  pic_value arg, ret;
 
   pic_get_args(pic, "l*", &proc, &argc, &args);
 
   ret = pic_nil_value();
   do {
-    cars = pic_nil_value();
-    for (i = argc - 1; i >= 0; --i) {
+    arg = pic_nil_value();
+    for (i = 0; i < argc; ++i) {
       if (! pic_pair_p(args[i])) {
         break;
       }
-      cars = pic_cons(pic, pic_car(pic, args[i]), cars);
+      pic_push(pic, pic_car(pic, args[i]), arg);
       args[i] = pic_cdr(pic, args[i]);
     }
-    if (i >= 0)
+    if (i != argc) {
       break;
-    ret = pic_cons(pic, pic_apply(pic, proc, cars), ret);
+    }
+    pic_push(pic, pic_apply(pic, proc, pic_reverse(pic, arg)), ret);
   } while (1);
 
   return pic_reverse(pic, ret);
@@ -671,22 +672,23 @@ pic_pair_for_each(pic_state *pic)
   struct pic_proc *proc;
   int argc, i;
   pic_value *args;
-  pic_value cars;
+  pic_value arg;
 
   pic_get_args(pic, "l*", &proc, &argc, &args);
 
   do {
-    cars = pic_nil_value();
-    for (i = argc - 1; i >= 0; --i) {
+    arg = pic_nil_value();
+    for (i = 0; i < argc; ++i) {
       if (! pic_pair_p(args[i])) {
         break;
       }
-      cars = pic_cons(pic, pic_car(pic, args[i]), cars);
+      pic_push(pic, pic_car(pic, args[i]), arg);
       args[i] = pic_cdr(pic, args[i]);
     }
-    if (i >= 0)
+    if (i != argc) {
       break;
-    pic_apply(pic, proc, cars);
+    }
+    pic_apply(pic, proc, pic_reverse(pic, arg));
   } while (1);
 
   return pic_none_value();

From 186c468c165cdfabc8ead6f85a39efbe4041dd4d Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 20:17:02 +0900
Subject: [PATCH 25/27] revert: argc must be size_t type

---
 blob.c   |  7 +++----
 bool.c   |  2 +-
 char.c   |  2 +-
 cont.c   |  4 ++--
 dict.c   |  2 +-
 error.c  |  4 ++--
 lib.c    |  8 ++++----
 number.c |  6 +++---
 pair.c   |  8 ++++----
 proc.c   |  2 +-
 string.c | 20 +++++++++-----------
 symbol.c |  2 +-
 vector.c | 19 ++++++++-----------
 vm.c     |  6 +++---
 14 files changed, 43 insertions(+), 49 deletions(-)

diff --git a/blob.c b/blob.c
index ae0f2fb7..3e5b7723 100644
--- a/blob.c
+++ b/blob.c
@@ -33,13 +33,13 @@ static pic_value
 pic_blob_bytevector(pic_state *pic)
 {
   pic_value *argv;
-  int argc, i;
+  size_t argc, i;
   pic_blob *blob;
   unsigned char *data;
 
   pic_get_args(pic, "*", &argc, &argv);
 
-  blob = pic_make_blob(pic, (size_t)argc);
+  blob = pic_make_blob(pic, argc);
 
   data = blob->data;
 
@@ -175,8 +175,7 @@ pic_blob_bytevector_copy(pic_state *pic)
 static pic_value
 pic_blob_bytevector_append(pic_state *pic)
 {
-  size_t j, len;
-  int argc, i;
+  size_t argc, i, j, len;
   pic_value *argv;
   pic_blob *blob;
 
diff --git a/bool.c b/bool.c
index ff5528e9..8f8c75f1 100644
--- a/bool.c
+++ b/bool.c
@@ -172,7 +172,7 @@ pic_bool_boolean_p(pic_state *pic)
 static pic_value
 pic_bool_boolean_eq_p(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
diff --git a/char.c b/char.c
index f08fcdd0..d9c675e7 100644
--- a/char.c
+++ b/char.c
@@ -42,7 +42,7 @@ pic_char_integer_to_char(pic_state *pic)
   static pic_value					\
   pic_char_##name##_p(pic_state *pic)			\
   {							\
-    int argc, i;                                        \
+    size_t argc, i;                                     \
     pic_value *argv;					\
     char c, d;						\
     							\
diff --git a/cont.c b/cont.c
index 4b980e4a..41a0fdb8 100644
--- a/cont.c
+++ b/cont.c
@@ -96,7 +96,7 @@ pic_load_point(pic_state *pic, struct pic_escape *escape)
 noreturn static pic_value
 escape_call(pic_state *pic)
 {
-  int argc;
+  size_t argc;
   pic_value *argv;
   struct pic_data *e;
 
@@ -251,7 +251,7 @@ pic_cont_dynamic_wind(pic_state *pic)
 static pic_value
 pic_cont_values(pic_state *pic)
 {
-  int argc;
+  size_t argc;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
diff --git a/dict.c b/dict.c
index 890af074..81bdea68 100644
--- a/dict.c
+++ b/dict.c
@@ -144,7 +144,7 @@ pic_dict_dictionary(pic_state *pic)
 {
   struct pic_dict *dict;
   pic_value *argv;
-  int argc, i;
+  size_t argc, i;
 
   pic_get_args(pic, "*", &argc, &argv);
 
diff --git a/error.c b/error.c
index 0f3ac651..3b462969 100644
--- a/error.c
+++ b/error.c
@@ -245,7 +245,7 @@ noreturn static pic_value
 pic_error_error(pic_state *pic)
 {
   const char *str;
-  int argc;
+  size_t argc;
   pic_value *argv;
 
   pic_get_args(pic, "z*", &str, &argc, &argv);
@@ -259,7 +259,7 @@ pic_error_make_error_object(pic_state *pic)
   struct pic_error *e;
   pic_sym type;
   pic_str *msg;
-  int argc;
+  size_t argc;
   pic_value *argv;
 
   pic_get_args(pic, "ms*", &type, &msg, &argc, &argv);
diff --git a/lib.c b/lib.c
index cd760f18..37cba2bd 100644
--- a/lib.c
+++ b/lib.c
@@ -253,7 +253,7 @@ static pic_value
 pic_lib_condexpand(pic_state *pic)
 {
   pic_value *clauses;
-  int argc, i;
+  size_t argc, i;
 
   pic_get_args(pic, "*", &argc, &clauses);
 
@@ -269,7 +269,7 @@ pic_lib_condexpand(pic_state *pic)
 static pic_value
 pic_lib_import(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -284,7 +284,7 @@ pic_lib_import(pic_state *pic)
 static pic_value
 pic_lib_export(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -300,7 +300,7 @@ static pic_value
 pic_lib_define_library(pic_state *pic)
 {
   struct pic_lib *prev = pic->lib;
-  int argc, i;
+  size_t argc, i;
   pic_value spec, *argv;
 
   pic_get_args(pic, "o*", &spec, &argc, &argv);
diff --git a/number.c b/number.c
index c72f58ca..88db88d6 100644
--- a/number.c
+++ b/number.c
@@ -162,7 +162,7 @@ pic_number_nan_p(pic_state *pic)
   static pic_value					\
   pic_number_##name(pic_state *pic)			\
   {							\
-    int argc, i;                                        \
+    size_t argc, i;                                     \
     pic_value *argv;					\
     double f,g;						\
     							\
@@ -197,7 +197,7 @@ DEFINE_ARITH_CMP(>=, ge)
   static pic_value                                              \
   pic_number_##name(pic_state *pic)                             \
   {                                                             \
-    int argc, i;                                                \
+    size_t argc, i;                                             \
     pic_value *argv;                                            \
     double f;                                                   \
     bool e = true;                                              \
@@ -228,7 +228,7 @@ DEFINE_ARITH_OP(*, mul, 1)
   static pic_value                                                      \
   pic_number_##name(pic_state *pic)                                     \
   {                                                                     \
-    int argc, i;                                                        \
+    size_t argc, i;                                                     \
    pic_value *argv;                                                     \
    double f;                                                            \
    bool e;                                                              \
diff --git a/pair.c b/pair.c
index cbb4de70..f2803f1a 100644
--- a/pair.c
+++ b/pair.c
@@ -544,7 +544,7 @@ pic_pair_make_list(pic_state *pic)
 static pic_value
 pic_pair_list(pic_state *pic)
 {
-  int argc;
+  size_t argc;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -565,7 +565,7 @@ pic_pair_length(pic_state *pic)
 static pic_value
 pic_pair_append(pic_state *pic)
 {
-  int argc;
+  size_t argc;
   pic_value *args, list;
 
   pic_get_args(pic, "*", &argc, &args);
@@ -641,7 +641,7 @@ static pic_value
 pic_pair_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i;
+  size_t argc, i;
   pic_value *args;
   pic_value arg, ret;
 
@@ -670,7 +670,7 @@ static pic_value
 pic_pair_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc, i;
+  size_t argc, i;
   pic_value *args;
   pic_value arg;
 
diff --git a/proc.c b/proc.c
index 0d67ddd7..210f157d 100644
--- a/proc.c
+++ b/proc.c
@@ -61,7 +61,7 @@ pic_proc_apply(pic_state *pic)
 {
   struct pic_proc *proc;
   pic_value *args;
-  int argc;
+  size_t argc;
   pic_value arg_list;
 
   pic_get_args(pic, "l*", &proc, &argc, &args);
diff --git a/string.c b/string.c
index cd4b3660..f9f15a59 100644
--- a/string.c
+++ b/string.c
@@ -233,7 +233,7 @@ pic_str_string_p(pic_state *pic)
 static pic_value
 pic_str_string(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
   pic_str *str;
   char *buf;
@@ -289,7 +289,7 @@ pic_str_string_ref(pic_state *pic)
   static pic_value                                                      \
   pic_str_string_##name(pic_state *pic)                                 \
   {                                                                     \
-    int argc, i;                                                        \
+    size_t argc, i;                                                     \
     pic_value *argv;                                                    \
                                                                         \
     pic_get_args(pic, "*", &argc, &argv);                               \
@@ -337,7 +337,7 @@ pic_str_string_copy(pic_state *pic)
 static pic_value
 pic_str_string_append(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
   pic_str *str;
 
@@ -357,14 +357,13 @@ static pic_value
 pic_str_string_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc;
   pic_value *argv, vals, val;
-  size_t i, len, j;
+  size_t argc, i, len, j;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = SIZE_MAX;
-  for (i = 0; i < (size_t)argc; ++i) {
+  for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], str);
 
     len = len < pic_strlen(pic_str_ptr(argv[i]))
@@ -379,7 +378,7 @@ pic_str_string_map(pic_state *pic)
 
     for (i = 0; i < len; ++i) {
       vals = pic_nil_value();
-      for (j = 0; j < (size_t)argc; ++j) {
+      for (j = 0; j < argc; ++j) {
         pic_push(pic, pic_char_value(pic_str_ref(pic, pic_str_ptr(argv[j]), i)), vals);
       }
       val = pic_apply(pic, proc, vals);
@@ -396,14 +395,13 @@ static pic_value
 pic_str_string_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc;
-  size_t len, i, j;
+  size_t argc, len, i, j;
   pic_value *argv, vals, val;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = SIZE_MAX;
-  for (i = 0; i < (size_t)argc; ++i) {
+  for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], str);
 
     len = len < pic_strlen(pic_str_ptr(argv[i]))
@@ -416,7 +414,7 @@ pic_str_string_for_each(pic_state *pic)
 
   for (i = 0; i < len; ++i) {
     vals = pic_nil_value();
-    for (j = 0; j < (size_t)argc; ++j) {
+    for (j = 0; j < argc; ++j) {
       pic_push(pic, pic_char_value(pic_str_ref(pic, pic_str_ptr(argv[j]), i)), vals);
     }
     val = pic_apply(pic, proc, vals);
diff --git a/symbol.c b/symbol.c
index 7e9f1b52..115582c8 100644
--- a/symbol.c
+++ b/symbol.c
@@ -108,7 +108,7 @@ pic_symbol_symbol_p(pic_state *pic)
 static pic_value
 pic_symbol_symbol_eq_p(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
 
   pic_get_args(pic, "*", &argc, &argv);
diff --git a/vector.c b/vector.c
index a7dbd81d..33070d24 100644
--- a/vector.c
+++ b/vector.c
@@ -51,7 +51,7 @@ pic_vec_vector_p(pic_state *pic)
 static pic_value
 pic_vec_vector(pic_state *pic)
 {
-  int argc, i;
+  size_t argc, i;
   pic_value *argv;
   pic_vec *vec;
 
@@ -188,9 +188,8 @@ pic_vec_vector_copy(pic_state *pic)
 static pic_value
 pic_vec_vector_append(pic_state *pic)
 {
-  int argc, i;
   pic_value *argv;
-  size_t j, len;
+  size_t argc, i, j, len;
   pic_vec *vec;
 
   pic_get_args(pic, "*", &argc, &argv);
@@ -242,15 +241,14 @@ static pic_value
 pic_vec_vector_map(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc;
-  size_t i, len, j;
+  size_t argc, i, len, j;
   pic_value *argv, vals;
   pic_vec *vec;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = INT_MAX;
-  for (i = 0; i < (size_t)argc; ++i) {
+  for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], vec);
 
     len = len < pic_vec_ptr(argv[i])->len
@@ -262,7 +260,7 @@ pic_vec_vector_map(pic_state *pic)
 
   for (i = 0; i < len; ++i) {
     vals = pic_nil_value();
-    for (j = 0; j < (size_t)argc; ++j) {
+    for (j = 0; j < argc; ++j) {
       pic_push(pic, pic_vec_ptr(argv[j])->data[i], vals);
     }
     vec->data[i] = pic_apply(pic, proc, vals);
@@ -275,14 +273,13 @@ static pic_value
 pic_vec_vector_for_each(pic_state *pic)
 {
   struct pic_proc *proc;
-  int argc;
-  size_t i, len, j;
+  size_t argc, i, len, j;
   pic_value *argv, vals;
 
   pic_get_args(pic, "l*", &proc, &argc, &argv);
 
   len = INT_MAX;
-  for (i = 0; i < (size_t)argc; ++i) {
+  for (i = 0; i < argc; ++i) {
     pic_assert_type(pic, argv[i], vec);
 
     len = len < pic_vec_ptr(argv[i])->len
@@ -292,7 +289,7 @@ pic_vec_vector_for_each(pic_state *pic)
 
   for (i = 0; i < len; ++i) {
     vals = pic_nil_value();
-    for (j = 0; j < (size_t)argc; ++j) {
+    for (j = 0; j < argc; ++j) {
       pic_push(pic, pic_vec_ptr(argv[j])->data[i], vals);
     }
     pic_apply(pic, proc, vals);
diff --git a/vm.c b/vm.c
index fbdd6c2b..accb47ce 100644
--- a/vm.c
+++ b/vm.c
@@ -416,13 +416,13 @@ pic_get_args(pic_state *pic, const char *format, ...)
     }
   }
   if ('*' == c) {
-    int *n;
+    size_t *n;
     pic_value **argv;
 
-    n = va_arg(ap, int *);
+    n = va_arg(ap, size_t *);
     argv = va_arg(ap, pic_value **);
     if (i <= argc) {
-      *n = argc - i;
+      *n = (size_t)(argc - i);
       *argv = &GET_OPERAND(pic, i);
       i = argc;
     }

From 0403ca5570c81004f5477cfd97f2ccd2ba9fe499 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 20:21:54 +0900
Subject: [PATCH 26/27] more fixes

---
 cont.c                | 16 ++++++++--------
 include/picrin/cont.h |  4 ++--
 include/picrin/pair.h |  2 +-
 pair.c                |  2 +-
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/cont.c b/cont.c
index 41a0fdb8..4e38e8c6 100644
--- a/cont.c
+++ b/cont.c
@@ -184,14 +184,14 @@ pic_values5(pic_state *pic, pic_value arg1, pic_value arg2, pic_value arg3, pic_
 }
 
 pic_value
-pic_values_by_array(pic_state *pic, int argc, pic_value *argv)
+pic_values_by_array(pic_state *pic, size_t argc, pic_value *argv)
 {
-  int i;
+  size_t i;
 
   for (i = 0; i < argc; ++i) {
     pic->sp[i] = argv[i];
   }
-  pic->ci->retc = argc;
+  pic->ci->retc = (int)argc;
 
   return argc == 0 ? pic_none_value() : pic->sp[0];
 }
@@ -211,15 +211,15 @@ pic_values_by_list(pic_state *pic, pic_value list)
   return pic_nil_p(list) ? pic_none_value() : pic->sp[0];
 }
 
-int
-pic_receive(pic_state *pic, int n, pic_value *argv)
+size_t
+pic_receive(pic_state *pic, size_t n, pic_value *argv)
 {
   pic_callinfo *ci;
-  int i, retc;
+  size_t i, retc;
 
   /* take info from discarded frame */
   ci = pic->ci + 1;
-  retc = ci->retc;
+  retc = (size_t)ci->retc;
 
   for (i = 0; i < retc && i < n; ++i) {
     argv[i] = ci->fp[i];
@@ -263,7 +263,7 @@ static pic_value
 pic_cont_call_with_values(pic_state *pic)
 {
   struct pic_proc *producer, *consumer;
-  int argc;
+  size_t argc;
   pic_value args[256];
 
   pic_get_args(pic, "ll", &producer, &consumer);
diff --git a/include/picrin/cont.h b/include/picrin/cont.h
index 01e86e11..645e6d9c 100644
--- a/include/picrin/cont.h
+++ b/include/picrin/cont.h
@@ -40,9 +40,9 @@ pic_value pic_values2(pic_state *, pic_value, pic_value);
 pic_value pic_values3(pic_state *, pic_value, pic_value, pic_value);
 pic_value pic_values4(pic_state *, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_values5(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value);
-pic_value pic_values_by_array(pic_state *, int, pic_value *);
+pic_value pic_values_by_array(pic_state *, size_t, pic_value *);
 pic_value pic_values_by_list(pic_state *, pic_value);
-int pic_receive(pic_state *, int, pic_value *);
+size_t pic_receive(pic_state *, size_t, pic_value *);
 
 pic_value pic_escape(pic_state *, struct pic_proc *);
 
diff --git a/include/picrin/pair.h b/include/picrin/pair.h
index d6cf779d..d489b765 100644
--- a/include/picrin/pair.h
+++ b/include/picrin/pair.h
@@ -56,7 +56,7 @@ pic_value pic_list4(pic_state *, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list5(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list6(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value);
 pic_value pic_list7(pic_state *, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value, pic_value);
-pic_value pic_list_by_array(pic_state *, int, pic_value *);
+pic_value pic_list_by_array(pic_state *, size_t, pic_value *);
 pic_value pic_make_list(pic_state *, size_t, pic_value);
 
 #define pic_for_each(var, list)                                 \
diff --git a/pair.c b/pair.c
index f2803f1a..b662534a 100644
--- a/pair.c
+++ b/pair.c
@@ -160,7 +160,7 @@ pic_list7(pic_state *pic, pic_value obj1, pic_value obj2, pic_value obj3, pic_va
 }
 
 pic_value
-pic_list_by_array(pic_state *pic, int c, pic_value *vs)
+pic_list_by_array(pic_state *pic, size_t c, pic_value *vs)
 {
   pic_value v;
 

From 1b371026761b7f65ac41a669ebc28eb18b4e7a07 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sat, 27 Sep 2014 20:43:31 +0900
Subject: [PATCH 27/27] suppress warning in compiling read.c

---
 read.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/read.c b/read.c
index 7deb5eb2..be160c0d 100644
--- a/read.c
+++ b/read.c
@@ -209,7 +209,7 @@ read_symbol(pic_state *pic, struct pic_port *port, const char *str)
 
   for (i = 0; i < len; ++i) {
     if (pic->reader->typecase == PIC_CASE_FOLD) {
-      buf[i] = tolower(str[i]);
+      buf[i] = (char)tolower(str[i]);
     } else {
       buf[i] = str[i];
     }
@@ -222,7 +222,7 @@ read_symbol(pic_state *pic, struct pic_port *port, const char *str)
     }
     len += 1;
     buf = pic_realloc(pic, buf, len + 1);
-    buf[len - 1] = c;
+    buf[len - 1] = (char)c;
   }
 
   sym = pic_intern(pic, buf, len);
@@ -240,9 +240,9 @@ read_uinteger(pic_state *pic, struct pic_port *port, int c, char buf[])
     read_error(pic, "expected one or more digits");
   }
 
-  buf[i++] = c;
+  buf[i++] = (char)c;
   while (isdigit(c = peek(port))) {
-    buf[i++] = next(port);
+    buf[i++] = (char)next(port);
   }
 
   buf[i] = '\0';
@@ -262,12 +262,12 @@ read_suffix(pic_state *pic, struct pic_port *port, char buf[])
     return i;
   }
 
-  buf[i++] = next(port);
+  buf[i++] = (char)next(port);
 
   switch ((c = next(port))) {
   case '-':
   case '+':
-    buf[i++] = c;
+    buf[i++] = (char)c;
     c = next(port);
   default:
     return i + read_uinteger(pic, port, c, buf + i);
@@ -284,14 +284,14 @@ read_unsigned(pic_state *pic, struct pic_port *port, int c)
 
   switch (peek(port)) {
   case '.':
-    buf[i++] = next(port);
+    buf[i++] = (char)next(port);
     i += read_uinteger(pic, port, next(port), buf + i);
     read_suffix(pic, port, buf + i);
     return pic_float_value(atof(buf));
 
   default:
     read_suffix(pic, port, buf + i);
-    return pic_int_value((int)atof(buf));
+    return pic_int_value((int)(atof(buf)));
   }
 }
 
@@ -404,7 +404,7 @@ read_char(pic_state *pic, struct pic_port *port, const char *str)
     }
   }
 
-  return pic_char_value(c);
+  return pic_char_value((char)c);
 
  fail:
   read_error(pic, "unexpected character while reading character literal");
@@ -436,7 +436,7 @@ read_string(pic_state *pic, struct pic_port *port, const char *name)
       case 'r': c = '\r'; break;
       }
     }
-    buf[cnt++] = c;
+    buf[cnt++] = (char)c;
     if (cnt >= size) {
       buf = pic_realloc(pic, buf, size *= 2);
     }
@@ -474,15 +474,15 @@ read_pipe(pic_state *pic, struct pic_port *port, const char *str)
       case 'r': c = '\r'; break;
       case 'x':
         i = 0;
-        while ((HEX_BUF[i++] = next(port)) != ';') {
+        while ((HEX_BUF[i++] = (char)next(port)) != ';') {
           if (i >= sizeof HEX_BUF)
             read_error(pic, "expected ';'");
         }
-        c = strtol(HEX_BUF, NULL, 16);
+        c = (char)strtol(HEX_BUF, NULL, 16);
         break;
       }
     }
-    buf[cnt++] = c;
+    buf[cnt++] = (char)c;
     if (cnt >= size) {
       buf = pic_realloc(pic, buf, size *= 2);
     }
@@ -500,7 +500,8 @@ read_blob(pic_state *pic, struct pic_port *port, const char *str)
 {
   int nbits, n, c;
   size_t len, i;
-  char *dat, buf[256];
+  char buf[256];
+  unsigned char *dat;
   pic_blob *blob;
 
   UNUSED(str);
@@ -530,7 +531,7 @@ read_blob(pic_state *pic, struct pic_port *port, const char *str)
     }
     len += 1;
     dat = pic_realloc(pic, dat, len);
-    dat[len - 1] = n;
+    dat[len - 1] = (unsigned char)n;
     c = next(port);
   }
 
@@ -710,7 +711,7 @@ read_nullable(pic_state *pic, struct pic_port *port, int c)
     read_error(pic, "invalid character at the seeker head");
   }
 
-  buf[i++] = c;
+  buf[i++] = (char)c;
 
   while (i < sizeof buf) {
     trie = trie->table[c];
@@ -721,7 +722,7 @@ read_nullable(pic_state *pic, struct pic_port *port, int c)
     if (trie->table[c] == NULL) {
       break;
     }
-    buf[i++] = next(port);
+    buf[i++] = (char)next(port);
   }
   if (i == sizeof buf) {
     read_error(pic, "too long dispatch string");