diff --git a/include/picrin.h b/include/picrin.h
deleted file mode 100644
index e58d5a61..00000000
--- a/include/picrin.h
+++ /dev/null
@@ -1,223 +0,0 @@
-/**
- * Copyright (c) 2013-2014 Yuichi Nishiwaki and other picrin contributors.
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
- * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
- * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
- * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
- * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef PICRIN_H__
-#define PICRIN_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-#include <stddef.h>
-#include <stdbool.h>
-#include <setjmp.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <limits.h>
-#include <assert.h>
-
-#include "xvect/xvect.h"
-#include "xhash/xhash.h"
-#include "xfile/xfile.h"
-#include "xrope/xrope.h"
-
-#include "picrin/config.h"
-#include "picrin/util.h"
-#include "picrin/value.h"
-
-typedef struct pic_code pic_code;
-
-typedef struct {
-  int argc, retc;
-  pic_code *ip;
-  pic_value *fp;
-  struct pic_env *env;
-  int regc;
-  pic_value *regs;
-  struct pic_env *up;
-} pic_callinfo;
-
-typedef struct {
-  int argc;
-  char **argv, **envp;
-
-  struct pic_block *blk;
-
-  pic_value *sp;
-  pic_value *stbase, *stend;
-
-  pic_callinfo *ci;
-  pic_callinfo *cibase, *ciend;
-
-  pic_code *ip;
-
-  struct pic_lib *lib;
-
-  pic_sym sDEFINE, sLAMBDA, sIF, sBEGIN, sQUOTE, sSETBANG;
-  pic_sym sQUASIQUOTE, sUNQUOTE, sUNQUOTE_SPLICING;
-  pic_sym sDEFINE_SYNTAX, sIMPORT, sEXPORT;
-  pic_sym sDEFINE_LIBRARY, sIN_LIBRARY;
-  pic_sym sCONS, sCAR, sCDR, sNILP;
-  pic_sym sADD, sSUB, sMUL, sDIV, sMINUS;
-  pic_sym sEQ, sLT, sLE, sGT, sGE, sNOT;
-
-  pic_sym rDEFINE, rLAMBDA, rIF, rBEGIN, rQUOTE, rSETBANG;
-  pic_sym rDEFINE_SYNTAX, rIMPORT, rEXPORT;
-  pic_sym rDEFINE_LIBRARY, rIN_LIBRARY;
-
-  xhash syms;                   /* name to symbol */
-  xhash sym_names;              /* symbol to name */
-  int sym_cnt;
-  int uniq_sym_cnt;
-
-  xhash globals;
-  xhash macros;
-  pic_value libs;
-
-  struct pic_reader *reader;
-
-  jmp_buf *jmp;
-  struct pic_error *err;
-  struct pic_jmpbuf *try_jmps;
-  size_t try_jmp_size, try_jmp_idx;
-
-  struct pic_heap *heap;
-  struct pic_object **arena;
-  size_t arena_size, arena_idx;
-
-  char *native_stack_start;
-} pic_state;
-
-typedef pic_value (*pic_func_t)(pic_state *);
-
-void *pic_alloc(pic_state *, size_t);
-#define pic_malloc(pic,size) pic_alloc(pic,size) /* obsoleted */
-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 *);
-pic_value pic_gc_protect(pic_state *, pic_value);
-size_t pic_gc_arena_preserve(pic_state *);
-void pic_gc_arena_restore(pic_state *, size_t);
-#define pic_void(exec)                          \
-  pic_void_(GENSYM(ai), exec)
-#define pic_void_(ai,exec) do {                 \
-    size_t ai = pic_gc_arena_preserve(pic);     \
-    exec;                                       \
-    pic_gc_arena_restore(pic, ai);              \
-  } while (0)
-
-pic_state *pic_open(int argc, char *argv[], char **envp);
-void pic_close(pic_state *);
-
-void pic_define(pic_state *, const char *, pic_value); /* automatic export */
-pic_value pic_ref(pic_state *, const char *);
-void pic_set(pic_state *, const char *, pic_value);
-
-pic_value pic_funcall(pic_state *pic, const char *name, pic_list args);
-
-struct pic_proc *pic_get_proc(pic_state *);
-int pic_get_args(pic_state *, const char *, ...);
-void pic_defun(pic_state *, const char *, pic_func_t);
-
-bool pic_equal_p(pic_state *, pic_value, pic_value);
-
-pic_sym pic_intern(pic_state *, const char *, size_t);
-pic_sym pic_intern_cstr(pic_state *, const char *);
-const char *pic_symbol_name(pic_state *, pic_sym);
-pic_sym pic_gensym(pic_state *, pic_sym);
-pic_sym pic_ungensym(pic_state *, pic_sym);
-bool pic_interned_p(pic_state *, pic_sym);
-
-char *pic_strdup(pic_state *, const char *);
-char *pic_strndup(pic_state *, const char *, size_t);
-
-pic_value pic_read(pic_state *, struct pic_port *);
-pic_value pic_read_cstr(pic_state *, const char *);
-pic_list pic_parse_file(pic_state *, FILE *); /* #f for incomplete input */
-pic_list pic_parse_cstr(pic_state *, const char *);
-
-pic_value pic_load(pic_state *, const char *);
-pic_value pic_load_cstr(pic_state *, const char *);
-
-pic_value pic_apply(pic_state *, struct pic_proc *, pic_value);
-pic_value pic_apply0(pic_state *, struct pic_proc *);
-pic_value pic_apply1(pic_state *, struct pic_proc *, pic_value);
-pic_value pic_apply2(pic_state *, struct pic_proc *, pic_value, pic_value);
-pic_value pic_apply3(pic_state *, struct pic_proc *, pic_value, pic_value, pic_value);
-pic_value pic_apply4(pic_state *, struct pic_proc *, pic_value, pic_value, pic_value, pic_value);
-pic_value pic_apply5(pic_state *, struct pic_proc *, pic_value, pic_value, pic_value, pic_value, pic_value);
-pic_value pic_apply_trampoline(pic_state *, struct pic_proc *, pic_value);
-pic_value pic_eval(pic_state *, pic_value, struct pic_lib *);
-struct pic_proc *pic_compile(pic_state *, pic_value, struct pic_lib *);
-pic_value pic_macroexpand(pic_state *, pic_value, struct pic_lib *);
-
-void pic_in_library(pic_state *, pic_value);
-struct pic_lib *pic_make_library(pic_state *, pic_value);
-struct pic_lib *pic_find_library(pic_state *, pic_value);
-
-#define pic_deflibrary(pic, spec)                                       \
-  pic_deflibrary_helper__(pic, GENSYM(i), GENSYM(prev_lib), spec)
-#define pic_deflibrary_helper__(pic, i, prev_lib, spec)                 \
-  for (int i = 0; ! i; )                                                \
-    for (struct pic_lib *prev_lib; ! i; )                               \
-      for ((prev_lib = pic->lib), pic_make_library(pic, pic_read_cstr(pic, spec)), pic_in_library(pic, pic_read_cstr(pic, spec)); ! i++; pic->lib = prev_lib)
-
-void pic_import(pic_state *, pic_value);
-void pic_export(pic_state *, pic_sym);
-
-noreturn void pic_abort(pic_state *, const char *);
-noreturn void pic_errorf(pic_state *, const char *, ...);
-void pic_warnf(pic_state *, const char *, ...);
-pic_str *pic_get_backtrace(pic_state *);
-void pic_print_backtrace(pic_state *, struct pic_error *);
-
-/* obsoleted */
-noreturn static inline void pic_error(pic_state *pic, const char *msg)
-{
-  pic_errorf(pic, msg);
-}
-static inline void pic_warn(pic_state *pic, const char *msg)
-{
-  pic_warnf(pic, msg);
-}
-
-const char *pic_errmsg(pic_state *);
-
-pic_value pic_write(pic_state *, pic_value); /* returns given obj */
-pic_value pic_fwrite(pic_state *, pic_value, xFILE *);
-void pic_printf(pic_state *, const char *, ...);
-pic_value pic_display(pic_state *, pic_value);
-pic_value pic_fdisplay(pic_state *, pic_value, xFILE *);
-/* obsoleted macros */
-#define pic_debug(pic,obj) pic_write(pic,obj)
-#define pic_fdebug(pic,obj,file) pic_fwrite(pic,obj,file)
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/blob.h b/include/picrin/blob.h
deleted file mode 100644
index f61f588d..00000000
--- a/include/picrin/blob.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_BLOB_H__
-#define PICRIN_BLOB_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_blob {
-  PIC_OBJECT_HEADER
-  char *data;
-  size_t len;
-};
-
-#define pic_blob_p(v) (pic_type(v) == PIC_TT_BLOB)
-#define pic_blob_ptr(v) ((struct pic_blob *)pic_ptr(v))
-
-struct pic_blob *pic_blob_new(pic_state *, size_t);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/config.h b/include/picrin/config.h
deleted file mode 100644
index 79b8fc3c..00000000
--- a/include/picrin/config.h
+++ /dev/null
@@ -1,115 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-/** contribution libraries */
-/* #define PIC_CONTRIB_INITS */
-
-/** switch normal VM and direct threaded VM */
-/* #define PIC_DIRECT_THREADED_VM 1 */
-
-/** switch internal value representation */
-/* #define PIC_NAN_BOXING 1 */
-
-/** enable readline module */
-/* #define PIC_ENABLE_READLINE 1 */
-
-/** treat false value as none */
-/* #define PIC_NONE_IS_FALSE 1 */
-
-/** initial memory size (to be dynamically extended if necessary) */
-/* #define PIC_ARENA_SIZE 1000 */
-
-/* #define PIC_HEAP_PAGE_SIZE 10000 */
-
-/* #define PIC_STACK_SIZE 1024 */
-
-/* #define PIC_RESCUE_SIZE 30 */
-
-/* #define PIC_SYM_POOL_SIZE 128 */
-
-/* #define PIC_IREP_SIZE 8 */
-
-/* #define PIC_POOL_SIZE 8 */
-
-/* #define PIC_ISEQ_SIZE 1024 */
-
-/** enable all debug flags */
-/* #define DEBUG 1 */
-
-/** auxiliary debug flags */
-/* #define GC_STRESS 1 */
-/* #define VM_DEBUG 1 */
-/* #define GC_DEBUG 1 */
-/* #define GC_DEBUG_DETAIL 1 */
-
-#if __STDC_VERSION__ < 199901L
-# error please activate c99 features
-#endif
-
-#ifndef PIC_CONTRIB_INITS
-# define PIC_CONTRIB_INITS
-#endif
-
-#ifndef PIC_DIRECT_THREADED_VM
-# if defined(__GNUC__) || defined(__CLANG__)
-#  define PIC_DIRECT_THREADED_VM 1
-# endif
-#endif
-
-#ifndef PIC_NAN_BOXING
-# if __x86_64__ && __STDC_VERSION__ >= 201112L
-#  define PIC_NAN_BOXING 1
-# endif
-#endif
-
-#ifndef PIC_ENABLE_READLINE
-# if PIC_READLINE_FOUND
-#  define PIC_ENABLE_READLINE 1
-# else
-#  define PIC_ENABLE_READLINE 0
-# endif
-#endif
-
-#ifndef PIC_NONE_IS_FALSE
-# define PIC_NONE_IS_FALSE 1
-#endif
-
-#ifndef PIC_ARENA_SIZE
-# define PIC_ARENA_SIZE 1000
-#endif
-
-#ifndef PIC_HEAP_PAGE_SIZE
-# define PIC_HEAP_PAGE_SIZE 10000
-#endif
-
-#ifndef PIC_STACK_SIZE
-# define PIC_STACK_SIZE 1024
-#endif
-
-#ifndef PIC_RESCUE_SIZE
-# define PIC_RESCUE_SIZE 30
-#endif
-
-#ifndef PIC_SYM_POOL_SIZE
-# define PIC_SYM_POOL_SIZE 128
-#endif
-
-#ifndef PIC_IREP_SIZE
-# define PIC_IREP_SIZE 8
-#endif
-
-#ifndef PIC_POOL_SIZE
-# define PIC_POOL_SIZE 8
-#endif
-
-#ifndef PIC_ISEQ_SIZE
-# define PIC_ISEQ_SIZE 1024
-#endif
-
-#if DEBUG
-# define GC_STRESS 0
-# define VM_DEBUG 1
-# define GC_DEBUG 0
-# define GC_DEBUG_DETAIL 0
-#endif
diff --git a/include/picrin/cont.h b/include/picrin/cont.h
deleted file mode 100644
index 0a0da9f1..00000000
--- a/include/picrin/cont.h
+++ /dev/null
@@ -1,62 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_CONT_H__
-#define PICRIN_CONT_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_block {
-  PIC_OBJECT_HEADER
-  struct pic_block *prev;
-  int depth;
-  struct pic_proc *in, *out;
-};
-
-struct pic_cont {
-  PIC_OBJECT_HEADER
-  jmp_buf jmp;
-
-  struct pic_block *blk;
-
-  char *stk_pos, *stk_ptr;
-  ptrdiff_t stk_len;
-
-  pic_value *st_ptr;
-  size_t sp_offset, st_len;
-
-  pic_callinfo *ci_ptr;
-  size_t ci_offset, ci_len;
-
-  pic_code *ip;
-
-  struct pic_object **arena;
-  size_t arena_size;
-  int arena_idx;
-
-  struct pic_jmpbuf *try_jmps;
-  size_t try_jmp_idx, try_jmp_size;
-
-  pic_value results;
-};
-
-pic_value pic_values0(pic_state *);
-pic_value pic_values1(pic_state *, pic_value);
-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_list(pic_state *, pic_value);
-size_t pic_receive(pic_state *, size_t, pic_value *);
-
-pic_value pic_callcc(pic_state *, struct pic_proc *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/data.h b/include/picrin/data.h
deleted file mode 100644
index a80ff209..00000000
--- a/include/picrin/data.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_DATA_H__
-#define PICRIN_DATA_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-typedef struct {
-  const char *type_name;
-  void (*dtor)(pic_state *, void *);
-} pic_data_type;
-
-struct pic_data {
-  PIC_OBJECT_HEADER;
-  const pic_data_type *type;
-  xhash storage;                /* const char * to pic_value table */
-  void *data;
-};
-
-#define pic_data_p(o) (pic_type(o) == PIC_TT_DATA)
-#define pic_data_ptr(o) ((struct pic_data *)pic_ptr(o))
-
-static inline bool pic_data_type_p(const pic_value obj, const pic_data_type *type) {
-  return pic_data_p(obj) && pic_data_ptr(obj)->type == type;
-}
-
-struct pic_data *pic_data_alloc(pic_state *, const pic_data_type *, void *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/dict.h b/include/picrin/dict.h
deleted file mode 100644
index 8bc58ad8..00000000
--- a/include/picrin/dict.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_DICT_H__
-#define PICRIN_DICT_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_dict {
-  PIC_OBJECT_HEADER
-  xhash hash;
-};
-
-#define pic_dict_p(v) (pic_type(v) == PIC_TT_DICT)
-#define pic_dict_ptr(v) ((struct pic_dict *)pic_ptr(v))
-
-struct pic_dict *pic_dict_new(pic_state *);
-
-pic_value pic_dict_ref(pic_state *, struct pic_dict *, pic_sym);
-void pic_dict_set(pic_state *, struct pic_dict *, pic_sym, pic_value);
-void pic_dict_del(pic_state *, struct pic_dict *, pic_sym);
-size_t pic_dict_size(pic_state *, struct pic_dict *);
-bool pic_dict_has(pic_state *, struct pic_dict *, pic_sym);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/error.h b/include/picrin/error.h
deleted file mode 100644
index bea590e2..00000000
--- a/include/picrin/error.h
+++ /dev/null
@@ -1,60 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_ERROR_H__
-#define PICRIN_ERROR_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_jmpbuf {
-  jmp_buf here;
-  struct pic_proc *handler;
-  ptrdiff_t ci_offset;
-  ptrdiff_t sp_offset;
-  pic_code *ip;
-  jmp_buf *prev_jmp;
-};
-
-/* do not return from try block! */
-
-#define pic_try                                 \
-  pic_try_with_handler(NULL)
-#define pic_try_with_handler(handler)           \
-  pic_push_try(pic, handler);                   \
-  if (setjmp(*pic->jmp) == 0)                   \
-    do
-#define pic_catch                               \
-    while (pic_pop_try(pic), 0);                \
-  else                                          \
-    if (pic_pop_try(pic), 1)
-
-void pic_push_try(pic_state *, struct pic_proc *);
-void pic_pop_try(pic_state *);
-
-noreturn void pic_throw(pic_state *, short, const char *, pic_value);
-noreturn void pic_throw_error(pic_state *, struct pic_error *);
-
-struct pic_error {
-  PIC_OBJECT_HEADER
-  enum pic_error_kind {
-    PIC_ERROR_OTHER,
-    PIC_ERROR_FILE,
-    PIC_ERROR_READ,
-    PIC_ERROR_RAISED
-  } type;
-  struct pic_string *msg;
-  pic_value irrs;
-  pic_str *stack;
-};
-
-#define pic_error_p(v) (pic_type(v) == PIC_TT_ERROR)
-#define pic_error_ptr(v) ((struct pic_error *)pic_ptr(v))
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/gc.h b/include/picrin/gc.h
deleted file mode 100644
index c5f33e6a..00000000
--- a/include/picrin/gc.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_GC_H__
-#define PICRIN_GC_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-#define PIC_GC_UNMARK 0
-#define PIC_GC_MARK 1
-
-struct pic_heap;
-
-struct pic_heap *pic_heap_open();
-void pic_heap_close(struct pic_heap *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/irep.h b/include/picrin/irep.h
deleted file mode 100644
index 4cb1cfba..00000000
--- a/include/picrin/irep.h
+++ /dev/null
@@ -1,206 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_IREP_H__
-#define PICRIN_IREP_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-enum pic_opcode {
-  OP_NOP,
-  OP_POP,
-  OP_PUSHNIL,
-  OP_PUSHTRUE,
-  OP_PUSHFALSE,
-  OP_PUSHINT,
-  OP_PUSHCHAR,
-  OP_PUSHCONST,
-  OP_GREF,
-  OP_GSET,
-  OP_LREF,
-  OP_LSET,
-  OP_CREF,
-  OP_CSET,
-  OP_JMP,
-  OP_JMPIF,
-  OP_NOT,
-  OP_CALL,
-  OP_TAILCALL,
-  OP_RET,
-  OP_LAMBDA,
-  OP_CONS,
-  OP_CAR,
-  OP_CDR,
-  OP_NILP,
-  OP_ADD,
-  OP_SUB,
-  OP_MUL,
-  OP_DIV,
-  OP_MINUS,
-  OP_EQ,
-  OP_LT,
-  OP_LE,
-  OP_STOP
-};
-
-struct pic_code {
-  enum pic_opcode insn;
-  union {
-    int i;
-    char c;
-    struct {
-      short depth;
-      short idx;
-    } r;
-  } u;
-};
-
-struct pic_irep {
-  PIC_OBJECT_HEADER
-  pic_sym name;
-  pic_code *code;
-  int argc, localc, capturec;
-  bool varg;
-  struct pic_irep **irep;
-  pic_value *pool;
-  size_t clen, ilen, plen;
-};
-
-pic_value pic_analyze(pic_state *, pic_value);
-struct pic_irep *pic_codegen(pic_state *, pic_value);
-
-static inline void
-pic_dump_code(pic_code c)
-{
-  printf("[%2d] ", c.insn);
-  switch (c.insn) {
-  case OP_NOP:
-    puts("OP_NOP");
-    break;
-  case OP_POP:
-    puts("OP_POP");
-    break;
-  case OP_PUSHNIL:
-    puts("OP_PUSHNIL");
-    break;
-  case OP_PUSHTRUE:
-    puts("OP_PUSHTRUE");
-    break;
-  case OP_PUSHFALSE:
-    puts("OP_PUSHFALSE");
-    break;
-  case OP_PUSHINT:
-    printf("OP_PUSHINT\t%d\n", c.u.i);
-    break;
-  case OP_PUSHCHAR:
-    printf("OP_PUSHCHAR\t%c\n", c.u.c);
-    break;
-  case OP_PUSHCONST:
-    printf("OP_PUSHCONST\t%d\n", c.u.i);
-    break;
-  case OP_GREF:
-    printf("OP_GREF\t%i\n", c.u.i);
-    break;
-  case OP_GSET:
-    printf("OP_GSET\t%i\n", c.u.i);
-    break;
-  case OP_LREF:
-    printf("OP_LREF\t%d\n", c.u.i);
-    break;
-  case OP_LSET:
-    printf("OP_LSET\t%d\n", c.u.i);
-    break;
-  case OP_CREF:
-    printf("OP_CREF\t%d\t%d\n", c.u.r.depth, c.u.r.idx);
-    break;
-  case OP_CSET:
-    printf("OP_CSET\t%d\t%d\n", c.u.r.depth, c.u.r.idx);
-    break;
-  case OP_JMP:
-    printf("OP_JMP\t%x\n", c.u.i);
-    break;
-  case OP_JMPIF:
-    printf("OP_JMPIF\t%x\n", c.u.i);
-    break;
-  case OP_NOT:
-    puts("OP_NOT");
-    break;
-  case OP_CALL:
-    printf("OP_CALL\t%d\n", c.u.i);
-    break;
-  case OP_TAILCALL:
-    printf("OP_TAILCALL\t%d\n", c.u.i);
-    break;
-  case OP_RET:
-    printf("OP_RET\t%d\n", c.u.i);
-    break;
-  case OP_LAMBDA:
-    printf("OP_LAMBDA\t%d\n", c.u.i);
-    break;
-  case OP_CONS:
-    puts("OP_CONS");
-    break;
-  case OP_CAR:
-    puts("OP_CAR");
-    break;
-  case OP_NILP:
-    puts("OP_NILP");
-    break;
-  case OP_CDR:
-    puts("OP_CDR");
-    break;
-  case OP_ADD:
-    puts("OP_ADD");
-    break;
-  case OP_SUB:
-    puts("OP_SUB");
-    break;
-  case OP_MUL:
-    puts("OP_MUL");
-    break;
-  case OP_DIV:
-    puts("OP_DIV");
-    break;
-  case OP_MINUS:
-    puts("OP_MINUS");
-    break;
-  case OP_EQ:
-    puts("OP_EQ");
-    break;
-  case OP_LT:
-    puts("OP_LT");
-    break;
-  case OP_LE:
-    puts("OP_LE");
-    break;
-  case OP_STOP:
-    puts("OP_STOP");
-    break;
-  }
-}
-
-static inline void
-pic_dump_irep(struct pic_irep *irep)
-{
-  unsigned i;
-
-  printf("## irep %p\n", (void *)irep);
-  printf("[clen = %zd, argc = %d, localc = %d, capturec = %d]\n", irep->clen, irep->argc, irep->localc, irep->capturec);
-  for (i = 0; i < irep->clen; ++i) {
-    printf("%02x ", i);
-    pic_dump_code(irep->code[i]);
-  }
-
-  for (i = 0; i < irep->ilen; ++i) {
-    pic_dump_irep(irep->irep[i]);
-  }
-}
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/lib.h b/include/picrin/lib.h
deleted file mode 100644
index ba43e49d..00000000
--- a/include/picrin/lib.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_LIB_H__
-#define PICRIN_LIB_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_lib {
-  PIC_OBJECT_HEADER
-  pic_value name;
-  struct pic_senv *env;
-  xhash exports;
-};
-
-#define pic_lib_ptr(o) ((struct pic_lib *)pic_ptr(o))
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/macro.h b/include/picrin/macro.h
deleted file mode 100644
index d655a735..00000000
--- a/include/picrin/macro.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_MACRO_H__
-#define PICRIN_MACRO_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_senv {
-  PIC_OBJECT_HEADER
-  xhash map;
-  struct pic_senv *up;
-};
-
-struct pic_macro {
-  PIC_OBJECT_HEADER
-  struct pic_proc *proc;
-  struct pic_senv *senv;
-};
-
-#define pic_macro_p(v) (pic_type(v) == PIC_TT_MACRO)
-#define pic_macro_ptr(v) ((struct pic_macro *)pic_ptr(v))
-
-#define pic_senv_p(v) (pic_type(v) == PIC_TT_SENV)
-#define pic_senv_ptr(v) ((struct pic_senv *)pic_ptr(v))
-
-struct pic_senv *pic_null_syntactic_environment(pic_state *);
-
-bool pic_identifier_p(pic_state *pic, pic_value obj);
-bool pic_identifier_eq_p(pic_state *, struct pic_senv *, pic_sym, struct pic_senv *, pic_sym);
-
-struct pic_senv *pic_senv_new(pic_state *, struct pic_senv *);
-
-pic_sym pic_add_rename(pic_state *, struct pic_senv *, pic_sym);
-bool pic_find_rename(pic_state *, struct pic_senv *, pic_sym, pic_sym * /* = NULL */);
-void pic_put_rename(pic_state *, struct pic_senv *, pic_sym, pic_sym);
-
-void pic_define_syntactic_keyword(pic_state *, struct pic_senv *, pic_sym, pic_sym);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/pair.h b/include/picrin/pair.h
deleted file mode 100644
index 49de01cc..00000000
--- a/include/picrin/pair.h
+++ /dev/null
@@ -1,76 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_PAIR_H__
-#define PICRIN_PAIR_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_pair {
-  PIC_OBJECT_HEADER
-  pic_value car;
-  pic_value cdr;
-};
-
-#define pic_pair_p(v) (pic_type(v) == PIC_TT_PAIR)
-#define pic_pair_ptr(o) ((struct pic_pair *)pic_ptr(o))
-
-pic_value pic_cons(pic_state *, pic_value, pic_value);
-pic_value pic_car(pic_state *, pic_value);
-pic_value pic_cdr(pic_state *, pic_value);
-void pic_set_car(pic_state *, pic_value, pic_value);
-void pic_set_cdr(pic_state *, pic_value, pic_value);
-
-bool pic_list_p(pic_value);
-pic_value pic_list1(pic_state *, pic_value);
-pic_value pic_list2(pic_state *, pic_value, pic_value);
-pic_value pic_list3(pic_state *, pic_value, pic_value, pic_value);
-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_make_list(pic_state *, int, pic_value);
-
-#define pic_for_each(var, list)                                 \
-  pic_for_each_helper__(var, GENSYM(tmp), list)
-#define pic_for_each_helper__(var, tmp, list)                           \
-  for (pic_value tmp = (list);                                          \
-       pic_nil_p(tmp) ? false : ((var = pic_car(pic, tmp)), true);      \
-       tmp = pic_cdr(pic, tmp))
-
-#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);
-pic_value pic_reverse(pic_state *, pic_value);
-pic_value pic_append(pic_state *, pic_value, pic_value);
-
-pic_value pic_memq(pic_state *, pic_value key, pic_value list);
-pic_value pic_memv(pic_state *, pic_value key, pic_value list);
-pic_value pic_member(pic_state *, pic_value key, pic_value list, struct pic_proc * /* = NULL */);
-
-pic_value pic_assq(pic_state *, pic_value key, pic_value assoc);
-pic_value pic_assv(pic_state *, pic_value key, pic_value assoc);
-pic_value pic_assoc(pic_state *, pic_value key, pic_value assoc, struct pic_proc * /* = NULL */);
-
-pic_value pic_acons(pic_state *, pic_value key, pic_value val, pic_value assoc);
-
-pic_value pic_caar(pic_state *, pic_value);
-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_copy(pic_state *, pic_value);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/port.h b/include/picrin/port.h
deleted file mode 100644
index e51d8759..00000000
--- a/include/picrin/port.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_PORT_H__
-#define PICRIN_PORT_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-enum pic_port_flag {
-  PIC_PORT_IN = 1,
-  PIC_PORT_OUT = 2,
-  PIC_PORT_TEXT = 4,
-  PIC_PORT_BINARY = 8,
-};
-
-enum pic_port_status {
-  PIC_PORT_OPEN,
-  PIC_PORT_CLOSE,
-};
-
-struct pic_port {
-  PIC_OBJECT_HEADER
-  xFILE *file;
-  int flags;
-  int status;
-};
-
-#define pic_port_p(v) (pic_type(v) == PIC_TT_PORT)
-#define pic_port_ptr(v) ((struct pic_port *)pic_ptr(v))
-
-pic_value pic_eof_object();
-
-struct pic_port *pic_stdin(pic_state *);
-struct pic_port *pic_stdout(pic_state *);
-struct pic_port *pic_stderr(pic_state *);
-
-struct pic_port *pic_open_input_string(pic_state *, const char *);
-struct pic_port *pic_open_output_string(pic_state *);
-struct pic_string *pic_get_output_string(pic_state *, struct pic_port *);
-
-void pic_close_port(pic_state *pic, struct pic_port *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/proc.h b/include/picrin/proc.h
deleted file mode 100644
index b91960de..00000000
--- a/include/picrin/proc.h
+++ /dev/null
@@ -1,62 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_PROC_H__
-#define PICRIN_PROC_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-/* native C function */
-struct pic_func {
-  pic_func_t f;
-  pic_sym name;
-};
-
-struct pic_env {
-  PIC_OBJECT_HEADER
-  pic_value *regs;
-  int regc;
-  struct pic_env *up;
-  pic_value storage[];
-};
-
-struct pic_proc {
-  PIC_OBJECT_HEADER
-  char kind;
-  union {
-    struct pic_func func;
-    struct pic_irep *irep;
-  } u;
-  struct pic_env *env;
-  struct pic_dict *attr;
-};
-
-#define PIC_PROC_KIND_FUNC 1
-#define PIC_PROC_KIND_IREP 2
-
-#define pic_proc_func_p(proc) ((proc)->kind == PIC_PROC_KIND_FUNC)
-#define pic_proc_irep_p(proc) ((proc)->kind == PIC_PROC_KIND_IREP)
-
-#define pic_proc_p(o) (pic_type(o) == PIC_TT_PROC)
-#define pic_proc_ptr(o) ((struct pic_proc *)pic_ptr(o))
-
-#define pic_env_p(o) (pic_type(o) == PIC_TT_ENV)
-#define pic_env_ptr(o) ((struct pic_env *)pic_ptr(o))
-
-struct pic_proc *pic_proc_new(pic_state *, pic_func_t, const char *);
-struct pic_proc *pic_proc_new_irep(pic_state *, struct pic_irep *, struct pic_env *);
-
-pic_sym pic_proc_name(struct pic_proc *);
-
-struct pic_dict *pic_attr(pic_state *, struct pic_proc *);
-pic_value pic_attr_ref(pic_state *, struct pic_proc *, const char *);
-void pic_attr_set(pic_state *, struct pic_proc *, const char *, pic_value);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/read.h b/include/picrin/read.h
deleted file mode 100644
index 8b977d58..00000000
--- a/include/picrin/read.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_READ_H__
-#define PICRIN_READ_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-enum pic_typecase {
-  PIC_CASE_DEFAULT,
-  PIC_CASE_FOLD,
-};
-
-struct pic_trie {
-  struct pic_trie *table[256];
-  struct pic_proc *proc;
-};
-
-struct pic_reader {
-  short typecase;
-  xhash labels;
-  struct pic_trie *trie;
-};
-
-void pic_init_reader(pic_state *);
-
-void pic_define_reader(pic_state *, const char *, pic_func_t);
-
-struct pic_trie *pic_trie_new(pic_state *);
-void pic_trie_delete(pic_state *, struct pic_trie *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/record.h b/include/picrin/record.h
deleted file mode 100644
index bf8698f1..00000000
--- a/include/picrin/record.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_RECORD_H
-#define PICRIN_RECORD_H
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_record {
-  PIC_OBJECT_HEADER
-  xhash     hash;
-};
-
-#define pic_record_p(v) (pic_type(v) == PIC_TT_RECORD)
-#define pic_record_ptr(v) ((struct pic_record *)pic_ptr(v))
-
-struct pic_record *pic_record_new(pic_state *, pic_value);
-
-pic_value pic_record_type(pic_state *, struct pic_record *);
-pic_value pic_record_ref(pic_state *, struct pic_record *, pic_sym);
-void pic_record_set(pic_state *, struct pic_record *, pic_sym, pic_value);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/string.h b/include/picrin/string.h
deleted file mode 100644
index c2564ffe..00000000
--- a/include/picrin/string.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_STRING_H__
-#define PICRIN_STRING_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_string {
-  PIC_OBJECT_HEADER
-  xrope *rope;
-};
-
-#define pic_str_p(v) (pic_type(v) == PIC_TT_STRING)
-#define pic_str_ptr(o) ((struct pic_string *)pic_ptr(o))
-
-pic_str *pic_str_new(pic_state *, const char * /* nullable */, size_t);
-pic_str *pic_str_new_cstr(pic_state *, const char *);
-pic_str *pic_str_new_fill(pic_state *, size_t, char);
-
-size_t pic_strlen(pic_str *);
-char pic_str_ref(pic_state *, pic_str *, size_t);
-void pic_str_set(pic_state *, pic_str *, size_t, char);
-
-pic_str *pic_strcat(pic_state *, pic_str *, pic_str *);
-pic_str *pic_substr(pic_state *, pic_str *, size_t, size_t);
-int pic_strcmp(pic_str *, pic_str *);
-
-const char *pic_str_cstr(pic_str *);
-
-pic_value pic_format(pic_state *, const char *, ...);
-pic_value pic_vformat(pic_state *, const char *, va_list);
-pic_value pic_vfformat(pic_state *, xFILE *, const char *, va_list);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/util.h b/include/picrin/util.h
deleted file mode 100644
index f2f5e719..00000000
--- a/include/picrin/util.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_UTIL_H__
-#define PICRIN_UTIL_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-#if __STDC_VERSION__ >= 201112L
-# include <stdnoreturn.h>
-#elif __GNUC__ || __clang__
-# define noreturn __attribute__((noreturn))
-#else
-# define noreturn
-#endif
-
-#define FALLTHROUGH ((void)0)
-#define UNUSED(v) ((void)(v))
-
-#define GENSYM2__(x,y) G##x##_##y##__
-#define GENSYM1__(x,y) GENSYM2__(x,y)
-#if defined(__COUNTER__)
-# define GENSYM(x) GENSYM1__(__COUNTER__,x)
-#else
-# define GENSYM(x) GENSYM1__(__LINE__,x)
-#endif
-
-#if GCC_VERSION >= 40500 || __clang__
-# define UNREACHABLE() (__builtin_unreachable())
-#else
-# include <assert.h>
-# define UNREACHABLE() (assert(false))
-#endif
-
-#define SWAP(type,a,b)                          \
-  SWAP_HELPER__(type,GENSYM(tmp),a,b)
-#define SWAP_HELPER__(type,tmp,a,b)             \
-  do {                                          \
-    type tmp = (a);                             \
-    (a) = (b);                                  \
-    (b) = tmp;                                  \
-  } while (0)
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/value.h b/include/picrin/value.h
deleted file mode 100644
index 6137c2eb..00000000
--- a/include/picrin/value.h
+++ /dev/null
@@ -1,484 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_VALUE_H__
-#define PICRIN_VALUE_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-/**
- * pic_sym is just an alias to unsigned int.
- */
-
-typedef int pic_sym;
-
-/**
- * `undef` values never seen from user-end: that is,
- *  it's used only for repsenting internal special state
- */
-
-enum pic_vtype {
-  PIC_VTYPE_NIL = 1,
-  PIC_VTYPE_TRUE,
-  PIC_VTYPE_FALSE,
-  PIC_VTYPE_UNDEF,
-  PIC_VTYPE_FLOAT,
-  PIC_VTYPE_INT,
-  PIC_VTYPE_SYMBOL,
-  PIC_VTYPE_CHAR,
-  PIC_VTYPE_EOF,
-  PIC_VTYPE_HEAP
-};
-
-#if PIC_NAN_BOXING
-
-/**
- * value representation by nan-boxing:
- *   float : FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF
- *   ptr   : 111111111111TTTT PPPPPPPPPPPPPPPP PPPPPPPPPPPPPPPP PPPPPPPPPPPPPPPP
- *   int   : 1111111111110110 0000000000000000 IIIIIIIIIIIIIIII IIIIIIIIIIIIIIII
- *   sym   : 1111111111110111 0000000000000000 SSSSSSSSSSSSSSSS SSSSSSSSSSSSSSSS
- *   char  : 1111111111111000 0000000000000000 CCCCCCCCCCCCCCCC ................
- */
-
-typedef struct {
-  union {
-    void *data;
-    double f;
-    struct {
-      union {
-	int i;
-	pic_sym sym;
-	char c;
-      };
-      uint32_t type_;
-    };
-  } u;
-} pic_value;
-
-#define pic_ptr(v) ((void *)((uint64_t)0xffffffffffff & (uint64_t)(v).u.data))
-#define pic_init_value(v,vtype) (((v).u.type_ = (((uint32_t)0xfff00000)|((uint32_t)((vtype)<<16)))), (v).u.i = 0)
-
-static inline enum pic_vtype
-pic_vtype(pic_value v)
-{
-  return 0xfff00000 >= v.u.type_
-    ? PIC_VTYPE_FLOAT
-    : (v.u.type_ & 0xf0000)>>16;
-}
-
-#else
-
-typedef struct {
-  enum pic_vtype type;
-  union {
-    void *data;
-    double f;
-    int i;
-    pic_sym sym;
-    char c;
-  } u;
-} pic_value;
-
-#define pic_ptr(v) ((v).u.data)
-#define pic_vtype(v) ((v).type)
-#define pic_init_value(v,vtype) ((v).type = (vtype), (v).u.data = NULL)
-
-#endif
-
-enum pic_tt {
-  /* immediate */
-  PIC_TT_NIL,
-  PIC_TT_BOOL,
-  PIC_TT_FLOAT,
-  PIC_TT_INT,
-  PIC_TT_SYMBOL,
-  PIC_TT_CHAR,
-  PIC_TT_EOF,
-  PIC_TT_UNDEF,
-  /* heap */
-  PIC_TT_PAIR,
-  PIC_TT_STRING,
-  PIC_TT_VECTOR,
-  PIC_TT_BLOB,
-  PIC_TT_PROC,
-  PIC_TT_PORT,
-  PIC_TT_ERROR,
-  PIC_TT_ENV,
-  PIC_TT_CONT,
-  PIC_TT_SENV,
-  PIC_TT_MACRO,
-  PIC_TT_LIB,
-  PIC_TT_VAR,
-  PIC_TT_IREP,
-  PIC_TT_DATA,
-  PIC_TT_DICT,
-  PIC_TT_RECORD,
-  PIC_TT_BLK,
-};
-
-#define PIC_OBJECT_HEADER			\
-  enum pic_tt tt;
-
-struct pic_object {
-  PIC_OBJECT_HEADER
-};
-
-struct pic_pair;
-struct pic_string;
-struct pic_vector;
-struct pic_blob;
-
-struct pic_proc;
-struct pic_port;
-
-/* set aliases to basic types */
-typedef pic_value pic_list;
-typedef struct pic_pair pic_pair;
-typedef struct pic_string pic_str;
-typedef struct pic_vector pic_vec;
-typedef struct pic_blob pic_blob;
-
-#define pic_float(v) ((v).u.f)
-#define pic_int(v) ((v).u.i)
-#define pic_sym(v) ((v).u.sym)
-#define pic_char(v) ((v).u.c)
-
-#define pic_obj_p(v) (pic_vtype(v) == PIC_VTYPE_HEAP)
-#define pic_obj_ptr(v) ((struct pic_object *)pic_ptr(v))
-
-#define pic_nil_p(v) (pic_vtype(v) == PIC_VTYPE_NIL)
-#define pic_true_p(v) (pic_vtype(v) == PIC_VTYPE_TRUE)
-#define pic_false_p(v) (pic_vtype(v) == PIC_VTYPE_FALSE)
-#define pic_undef_p(v) (pic_vtype(v) == PIC_VTYPE_UNDEF)
-#define pic_float_p(v) (pic_vtype(v) == PIC_VTYPE_FLOAT)
-#define pic_int_p(v) (pic_vtype(v) == PIC_VTYPE_INT)
-#define pic_sym_p(v) (pic_vtype(v) == PIC_VTYPE_SYMBOL)
-#define pic_char_p(v) (pic_vtype(v) == PIC_VTYPE_CHAR)
-#define pic_eof_p(v) (pic_vtype(v) == PIC_VTYPE_EOF)
-
-#define pic_test(v) (! pic_false_p(v))
-
-static inline enum pic_tt pic_type(pic_value);
-static inline const char *pic_type_repr(enum pic_tt);
-
-#define pic_assert_type(pic, v, type)                           \
-  if (! pic_##type##_p(v)) {                                    \
-    pic_errorf(pic, "expected " #type ", but got ~s", v);       \
-  }
-
-static inline bool pic_valid_int(double);
-
-static inline pic_value pic_nil_value();
-static inline pic_value pic_true_value();
-static inline pic_value pic_false_value();
-static inline pic_value pic_bool_value(bool);
-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_sym_value(pic_sym);
-static inline pic_value pic_char_value(char c);
-static inline pic_value pic_none_value();
-
-#define pic_symbol_value(sym) pic_sym_value(sym)
-
-static inline bool pic_eq_p(pic_value, pic_value);
-static inline bool pic_eqv_p(pic_value, pic_value);
-
-static inline enum pic_tt
-pic_type(pic_value v)
-{
-  switch (pic_vtype(v)) {
-  case PIC_VTYPE_NIL:
-    return PIC_TT_NIL;
-  case PIC_VTYPE_TRUE:
-    return PIC_TT_BOOL;
-  case PIC_VTYPE_FALSE:
-    return PIC_TT_BOOL;
-  case PIC_VTYPE_UNDEF:
-    return PIC_TT_UNDEF;
-  case PIC_VTYPE_FLOAT:
-    return PIC_TT_FLOAT;
-  case PIC_VTYPE_INT:
-    return PIC_TT_INT;
-  case PIC_VTYPE_SYMBOL:
-    return PIC_TT_SYMBOL;
-  case PIC_VTYPE_CHAR:
-    return PIC_TT_CHAR;
-  case PIC_VTYPE_EOF:
-    return PIC_TT_EOF;
-  case PIC_VTYPE_HEAP:
-    return ((struct pic_object *)pic_ptr(v))->tt;
-  default:
-    return -1;                  /* logic flaw */
-  }
-}
-
-static inline const char *
-pic_type_repr(enum pic_tt tt)
-{
-  switch (tt) {
-  case PIC_TT_NIL:
-    return "nil";
-  case PIC_TT_BOOL:
-    return "boolean";
-  case PIC_TT_FLOAT:
-    return "float";
-  case PIC_TT_INT:
-    return "int";
-  case PIC_TT_SYMBOL:
-    return "symbol";
-  case PIC_TT_CHAR:
-    return "char";
-  case PIC_TT_EOF:
-    return "eof";
-  case PIC_TT_UNDEF:
-    return "undef";
-  case PIC_TT_PAIR:
-    return "pair";
-  case PIC_TT_STRING:
-    return "string";
-  case PIC_TT_VECTOR:
-    return "vector";
-  case PIC_TT_BLOB:
-    return "blob";
-  case PIC_TT_PORT:
-    return "port";
-  case PIC_TT_ERROR:
-    return "error";
-  case PIC_TT_ENV:
-    return "env";
-  case PIC_TT_CONT:
-    return "cont";
-  case PIC_TT_PROC:
-    return "proc";
-  case PIC_TT_SENV:
-    return "senv";
-  case PIC_TT_MACRO:
-    return "macro";
-  case PIC_TT_LIB:
-    return "lib";
-  case PIC_TT_VAR:
-    return "var";
-  case PIC_TT_IREP:
-    return "irep";
-  case PIC_TT_DATA:
-    return "data";
-  case PIC_TT_DICT:
-    return "dict";
-  case PIC_TT_RECORD:
-    return "record";
-  case PIC_TT_BLK:
-    return "block";
-  }
-  UNREACHABLE();
-}
-
-static inline bool
-pic_valid_int(double v)
-{
-  return INT_MIN <= v && v <= INT_MAX;
-}
-
-static inline pic_value
-pic_nil_value()
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_NIL);
-  return v;
-}
-
-static inline pic_value
-pic_true_value()
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_TRUE);
-  return v;
-}
-
-static inline pic_value
-pic_false_value()
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_FALSE);
-  return v;
-}
-
-static inline pic_value
-pic_bool_value(bool b)
-{
-  pic_value v;
-
-  pic_init_value(v, b ? PIC_VTYPE_TRUE : PIC_VTYPE_FALSE);
-  return v;
-}
-
-#if PIC_NAN_BOXING
-
-static inline pic_value
-pic_obj_value(void *ptr)
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_HEAP);
-  v.u.data = (void*)((long long)v.u.data | ((long long)ptr));
-  return v;
-}
-
-static inline pic_value
-pic_float_value(double f)
-{
-  pic_value v;
-
-  if (f != f) {
-    v.u.type_ = 0x7ff80000;
-    v.u.i = 0;
-  } else {
-    v.u.f = f;
-  }
-  return v;
-}
-
-#else
-
-static inline pic_value
-pic_obj_value(void *ptr)
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_HEAP);
-  v.u.data = ptr;
-  return v;
-}
-
-static inline pic_value
-pic_float_value(double f)
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_FLOAT);
-  v.u.f = f;
-  return v;
-}
-
-#endif
-
-static inline pic_value
-pic_int_value(int i)
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_INT);
-  v.u.i = i;
-  return v;
-}
-
-static inline pic_value
-pic_symbol_value(pic_sym sym)
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_SYMBOL);
-  v.u.sym = sym;
-  return v;
-}
-
-static inline pic_value
-pic_char_value(char c)
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_CHAR);
-  v.u.c = c;
-  return v;
-}
-
-static inline pic_value
-pic_undef_value()
-{
-  pic_value v;
-
-  pic_init_value(v, PIC_VTYPE_UNDEF);
-  return v;
-}
-
-static inline pic_value
-pic_none_value()
-{
-#if PIC_NONE_IS_FALSE
-  return pic_false_value();
-#else
-# error enable PIC_NONE_IS_FALSE
-#endif
-}
-
-#if PIC_NAN_BOXING
-
-static inline bool
-pic_eq_p(pic_value x, pic_value y)
-{
-  return x.u.data == y.u.data;
-}
-
-static inline bool
-pic_eqv_p(pic_value x, pic_value y)
-{
-  return x.u.data == y.u.data;
-}
-
-#else
-
-static inline bool
-pic_eq_p(pic_value x, pic_value y)
-{
-  if (pic_type(x) != pic_type(y))
-    return false;
-
-  switch (pic_type(x)) {
-  case PIC_TT_NIL:
-    return true;
-  case PIC_TT_BOOL:
-    return pic_vtype(x) == pic_vtype(y);
-  case PIC_TT_SYMBOL:
-    return pic_sym(x) == pic_sym(y);
-  default:
-    return pic_ptr(x) == pic_ptr(y);
-  }
-}
-
-static inline bool
-pic_eqv_p(pic_value x, pic_value y)
-{
-  if (pic_type(x) != pic_type(y))
-    return false;
-
-  switch (pic_type(x)) {
-  case PIC_TT_NIL:
-    return true;
-  case PIC_TT_BOOL:
-    return pic_vtype(x) == pic_vtype(y);
-  case PIC_TT_SYMBOL:
-    return pic_sym(x) == pic_sym(y);
-  case PIC_TT_FLOAT:
-    return pic_float(x) == pic_float(y);
-  case PIC_TT_INT:
-    return pic_int(x) == pic_int(y);
-  default:
-    return pic_ptr(x) == pic_ptr(y);
-  }
-}
-
-#endif
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/var.h b/include/picrin/var.h
deleted file mode 100644
index d3bbaf4e..00000000
--- a/include/picrin/var.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_VAR_H__
-#define PICRIN_VAR_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_var {
-  PIC_OBJECT_HEADER
-  pic_value stack;
-  struct pic_proc *conv;
-};
-
-#define pic_var_p(o) (pic_type(o) == PIC_TT_VAR)
-#define pic_var_ptr(o) ((struct pic_var *)pic_ptr(o))
-
-struct pic_var *pic_var_new(pic_state *, pic_value, struct pic_proc * /* = NULL */);
-
-pic_value pic_var_ref(pic_state *, struct pic_var *);
-void pic_var_set(pic_state *, struct pic_var *, pic_value);
-void pic_var_push(pic_state *, struct pic_var *, pic_value);
-void pic_var_pop(pic_state *, struct pic_var *);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif
diff --git a/include/picrin/vector.h b/include/picrin/vector.h
deleted file mode 100644
index 80a4cb73..00000000
--- a/include/picrin/vector.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/**
- * See Copyright Notice in picrin.h
- */
-
-#ifndef PICRIN_VECTOR_H__
-#define PICRIN_VECTOR_H__
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-struct pic_vector {
-  PIC_OBJECT_HEADER
-  pic_value *data;
-  size_t len;
-};
-
-#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_vec_new(pic_state *, size_t);
-struct pic_vector *pic_vec_new_from_list(pic_state *, pic_value);
-void pic_vec_extend_ip(pic_state *, struct pic_vector *, size_t);
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif