diff --git a/old/Makefile b/old/Makefile
deleted file mode 100644
index f2dfeb2..0000000
--- a/old/Makefile
+++ /dev/null
@@ -1,9 +0,0 @@
-CFLAGS	:= -std=gnu99 -Og -g -Wpedantic -Wall
-OBJS	:= util.o symbol.o object.o gc.o print.o lex.o read.o eval.o main.o
-
-wscm: $(OBJS)
-	$(CC) $(OBJS) -o wscm
-
-.PHONY: clean
-clean:
-	rm -f wscm $(OBJS)
diff --git a/old/README.md b/old/README.md
deleted file mode 100644
index b282a8e..0000000
--- a/old/README.md
+++ /dev/null
@@ -1,14 +0,0 @@
-# wolfscheme
-
-An experiment in how quick I can get from zero to a decent Lisp.
-Don't know why I called it `wolfscheme`.
-
-## Day 1:
-
-- Symbol interning
-- Garbage collector and cons pairs
-- Object printing
-
-## Day 2:
-
-- Tree-walking evaluator with a few primitives
diff --git a/old/eval.c b/old/eval.c
deleted file mode 100644
index 58fa416..0000000
--- a/old/eval.c
+++ /dev/null
@@ -1,226 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "wscm.h"
-
-static O listrev(O list) {
-  O prev = NIL;
-  O curr = list;
-  O next;
-
-  while (curr != NIL) {
-    C *c = uncons(curr);
-    next = c->cdr;
-    c->cdr = prev;
-    prev = curr;
-    curr = next;
-  }
-  return prev;
-}
-
-O pair_assoc(O v, O env) {
-  while (kind(env) == KIND_CONS) {
-    C *c = uncons(env);
-    O pair = c->car;
-    if (pair == NIL) {
-      env = c->cdr;
-      continue;
-    }
-    if (kind(pair) == KIND_CONS) {
-      C *kv = uncons(pair);
-      if (kv->car == v)
-        return pair;
-    }
-    env = c->cdr;
-  }
-  return NIL;
-}
-
-O bind(O params, O args, O env) {
-  I mark = rootmark();
-  addroot(&params);
-  addroot(&args);
-  addroot(&env);
-
-  O res = env;
-  addroot(&res);
-
-  while (params != NIL) {
-    if (kind(params) == KIND_SYM) {
-      O pair = cons(params, args);
-      addroot(&pair);
-      res = cons(pair, res);
-      break;
-    }
-
-    if (kind(params) != KIND_CONS) {
-      fprintf(stderr, "error: expected proper list or symbol for parameters\n");
-      abort();
-    }
-
-    C *p = uncons(params);
-    O sym = p->car;
-
-    O val = NIL;
-    if (args != NIL) {
-      if (kind(args) != KIND_CONS) {
-        fprintf(stderr, "error: too many parameters for arguments\n");
-        abort();
-      }
-      C *a = uncons(args);
-      val = a->car;
-      args = a->cdr;
-    }
-
-    O pair = cons(sym, val);
-    addroot(&pair);
-    res = cons(pair, res);
-
-    params = p->cdr;
-  }
-
-  rootreset(mark);
-  return res;
-}
-
-O eval(O obj, O env);
-
-static O evallist(O list, O env) {
-  I mark = rootmark();
-  addroot(&list);
-  addroot(&env);
-
-  O head = NIL;
-  addroot(&head);
-
-  O curr = list;
-  addroot(&curr);
-
-  while (curr != NIL) {
-    C *c = uncons(curr);
-    O val = eval(c->car, env);
-    head = cons(val, head);
-    curr = c->cdr;
-  }
-
-  O res = listrev(head);
-
-  rootreset(mark);
-  return res;
-}
-
-/* primitives */
-
-O prim_cons(O args, O env) {
-  args = evallist(args, env);
-
-  O x = uncons(args)->car;
-  args = uncons(args)->cdr;
-  O y = uncons(args)->car;
-  return cons(x, y);
-}
-
-O prim_car(O args, O env) {
-  args = evallist(args, env);
-  O list = uncons(args)->car;
-  return uncons(list)->car;
-}
-
-O prim_cdr(O args, O env) {
-  args = evallist(args, env);
-  O list = uncons(args)->car;
-  return uncons(list)->cdr;
-}
-
-O prim_quote(O args, O env) {
-  if (args == NIL)
-    return NIL;
-  return uncons(args)->car;
-}
-
-O prim_if(O args, O env) {
-  C *ac = uncons(args);
-  O cond = eval(ac->car, env);
-  args = ac->cdr;
-  if (args == NIL)
-    return NIL;
-  ac = uncons(args);
-  if (cond != NIL) {
-    return eval(ac->car, env);
-  } else {
-    if (ac->cdr == NIL)
-      return NIL;
-    return eval(uncons(ac->cdr)->car, env);
-  }
-}
-
-O mkprim(const char *name, O (*fn)(O, O)) {
-  P *p = malloc(sizeof(P));
-  p->name = name;
-  p->fn = fn;
-  O sym = BOX(TAG(intern(name, -1), TAG_SYM));
-  O prim = BOX(TAG(p, TAG_PRIM));
-  return cons(sym, prim);
-}
-
-V setupenv(O *env) {
-  O t = BOX(TAG(intern("t", 1), TAG_SYM));
-  *env = cons(cons(t, t), *env);
-
-  O nil = BOX(TAG(intern("nil", 3), TAG_SYM));
-  *env = cons(cons(nil, NIL), *env);
-
-  *env = cons(mkprim("cons", prim_cons), *env);
-  *env = cons(mkprim("car", prim_car), *env);
-  *env = cons(mkprim("cdr", prim_cdr), *env);
-  *env = cons(mkprim("quote", prim_quote), *env);
-  *env = cons(mkprim("if", prim_if), *env);
-}
-
-O apply(O fn, O args, O env) {
-  I k = kind(fn);
-  switch (k) {
-  case KIND_PRIM: {
-    P *p = (P *)UNTAG(fn);
-    return p->fn(args, env);
-  }
-  case KIND_CLOS: {
-    H *h = UNBOX(fn);
-    L *l = (L *)(h + 1);
-    args = evallist(args, env);
-    O nenv = bind(l->args, args, l->env);
-    return eval(l->body, nenv);
-  }
-  default:
-    fprintf(stderr, "tried to call non-function value\n");
-    abort();
-  }
-}
-
-O eval(O obj, O env) {
-  I k = kind(obj);
-
-  if (k == KIND_SYM) {
-    O pair = pair_assoc(obj, env);
-    if (pair == NIL) {
-      S *s = (S *)UNTAG(obj);
-      fprintf(stderr, "error: undefined symbol '%.*s'\n", (int)s->len, s->data);
-      abort();
-    }
-    return uncons(pair)->cdr;
-  } else if (k != KIND_CONS) {
-    return obj;
-  }
-
-  I mark = rootmark();
-  addroot(&obj);
-  addroot(&env);
-
-  C *c = uncons(obj);
-  O fn = eval(c->car, env);
-  addroot(&fn);
-
-  O res = apply(fn, c->cdr, env);
-  rootreset(mark);
-  return res;
-}
diff --git a/old/gc.c b/old/gc.c
deleted file mode 100644
index f80838a..0000000
--- a/old/gc.c
+++ /dev/null
@@ -1,136 +0,0 @@
-#include <assert.h>
-#include <stdio.h>
-#include <string.h>
-
-#include "inttypes.h"
-#include "stdlib.h"
-#include "wscm.h"
-
-E heap;
-
-// roots management
-void addroot(O *ptr) {
-  if (heap.root_count >= heap.root_capacity) {
-    Z cap = heap.root_capacity == 0 ? 16 : heap.root_capacity * 2;
-    O **roots = realloc(heap.roots, cap * sizeof(O *));
-    if (!roots)
-      abort();
-    heap.roots = roots;
-    heap.root_capacity = cap;
-  }
-  heap.roots[heap.root_count++] = ptr;
-}
-
-I rootmark(void) { return heap.root_count; }
-void rootreset(I mark) { heap.root_count = mark; }
-
-// garbage collection
-static O copy(H *obj, U8 **freep) {
-  assert(INFROM(obj));
-  assert(obj->type != OBJ_FWD);
-
-  Z sz = ALIGN(obj->size);
-  H *new = (H *)*freep;
-  *freep += sz;
-  memcpy(new, obj, sz);
-  obj->type = OBJ_FWD;
-  O *o = (O *)(obj + 1);
-  *o = BOX(new);
-  return *o;
-}
-
-static O forward(O obj, U8 **freep) {
-  if (obj == NIL)
-    return NIL;
-  if (IMM(obj))
-    return obj;
-  if (TYPE(obj) != TAG_GC)
-    return obj;
-
-  H *h = UNBOX(obj);
-  if (!INFROM(h))
-    return obj;
-
-  if (h->type == OBJ_FWD) {
-    O *o = (O *)(h + 1);
-    return *o;
-  } else {
-    return copy(h, freep);
-  }
-}
-
-void collect(void) {
-  U8 *freep = heap.to.start;
-  U8 *scan = freep;
-
-  for (I i = 0; i < heap.root_count; i++) {
-    O *o = heap.roots[i];
-    *o = forward(*o, &freep);
-  }
-
-  while (scan < freep) {
-    H *h = (H *)scan;
-    switch (h->type) {
-    case OBJ_CONS: {
-      C *c = (C *)(h + 1);
-      c->car = forward(c->car, &freep);
-      c->cdr = forward(c->cdr, &freep);
-      break;
-    }
-    case OBJ_FWD:
-      fprintf(stderr, "gc internal error: forwarding pointer in to-space\n");
-      abort();
-    default:
-      fprintf(stderr, "gc internal error: junk object type %" PRIdPTR "\n",
-              h->type);
-      abort();
-    }
-    scan += ALIGN(h->size);
-  }
-
-  U8 *tmp_start, *tmp_end;
-  tmp_start = heap.from.start;
-  tmp_end = heap.from.end;
-
-  heap.from = heap.to;
-  heap.from.free = freep;
-
-  heap.to.start = tmp_start;
-  heap.to.end = tmp_end;
-  heap.to.free = tmp_start;
-}
-
-// allocation
-H *alloc(Z sz) {
-  sz = ALIGN(sz);
-  if (heap.from.free + sz > heap.from.end) {
-    collect();
-    if (heap.from.free + sz > heap.from.end) {
-      fprintf(stderr, "out of memory (requested %zu bytes)\n", sz);
-      abort();
-    }
-  }
-  H *p = (H *)heap.from.free;
-  heap.from.free += sz;
-  p->size = sz;
-  return p;
-}
-
-void gcinit(void) {
-  heap.from.start = malloc(GC_HEAP_BYTES);
-  if (!heap.from.start)
-    abort();
-  heap.from.free = heap.from.start;
-  heap.from.end = heap.from.start + GC_HEAP_BYTES;
-
-  heap.to.start = malloc(GC_HEAP_BYTES);
-  if (!heap.to.start)
-    abort();
-  heap.to.free = heap.to.start;
-  heap.to.end = heap.to.start + GC_HEAP_BYTES;
-}
-
-void gcfinalize(void) {
-  free(heap.from.start);
-  free(heap.to.start);
-}
diff --git a/old/lex.c b/old/lex.c
deleted file mode 100644
index 9e50cd9..0000000
--- a/old/lex.c
+++ /dev/null
@@ -1,119 +0,0 @@
-
-#include <err.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "wscm.h"
-
-// helpers
-static int iswhite(int ch) { return ch == ' ' || ch == '\t' || ch == '\n'; }
-
-static int isdelim(int ch) {
-  return ch == '(' || ch == ')' || ch == '\'' || ch == ';';
-}
-
-static inline void appendchar(Lx *lex, char ch) {
-  if (lex->cursor > LEXER_CAP) {
-    fprintf(stderr, "lexer buffer overflow");
-    abort();
-  }
-  lex->buffer[lex->cursor++] = ch;
-}
-
-static int getcws(Lx *lex) {
-  if (feof(lex->input))
-    return EOF;
-  for (;;) {
-    int ch = getc(lex->input);
-    if (iswhite(ch))
-      continue;
-    return ch;
-  }
-}
-
-static int scanword(Lx *lex) {
-  int ch = getc(lex->input);
-  for (;;) {
-    if (ch == EOF) {
-      if (lex->cursor == 0)
-        lex->kind = TOK_EOF;
-      appendchar(lex, 0);
-      return lex->kind;
-    } else if (iswhite(ch) || isdelim(ch)) {
-      ungetc(ch, lex->input);
-      appendchar(lex, 0);
-      return lex->kind;
-    } else {
-      appendchar(lex, ch);
-      ch = getc(lex->input);
-    }
-  }
-}
-
-static int scanstring(Lx *lex) {
-  int ch;
-  for (;;) {
-    ch = getc(lex->input);
-    switch (ch) {
-    case EOF:
-      goto eof;
-    case '\\':
-      ch = getc(lex->input);
-      if (ch == EOF)
-        goto eof;
-      switch (ch) {
-      case 'n':
-        appendchar(lex, '\n');
-        break;
-      case 't':
-        appendchar(lex, '\t');
-        break;
-      case '"':
-        appendchar(lex, '"');
-        break;
-      }
-      break;
-    case '"':
-      appendchar(lex, 0);
-      return (lex->kind = TOK_STRING);
-    default:
-      appendchar(lex, ch);
-    }
-  }
-
-eof:
-  errx(1, "unterminated string literal");
-}
-
-int nexttoken(Lx *lex) {
-  int ch;
-  lex->cursor = 0;
-
-  if (feof(lex->input)) {
-    lex->kind = TOK_EOF;
-    *lex->buffer = 0;
-    return 0;
-  }
-
-  ch = getcws(lex);
-  switch (ch) {
-  case ';':
-    for (; ch != '\n'; ch = getc(lex->input))
-      appendchar(lex, ch);
-    appendchar(lex, 0);
-    return (lex->kind = TOK_COMMENT);
-  case '(':
-  case ')':
-  case '.':
-  case '\'':
-    return (lex->kind = ch);
-  case '"':
-    return scanstring(lex);
-  default:
-    ungetc(ch, lex->input);
-    lex->kind = TOK_WORD;
-    return scanword(lex);
-  }
-
-  return 0;
-}
diff --git a/old/main.c b/old/main.c
deleted file mode 100644
index 3f0e751..0000000
--- a/old/main.c
+++ /dev/null
@@ -1,23 +0,0 @@
-#include <stdio.h>
-
-#include "wscm.h"
-
-int main(void) {
-  gcinit();
-
-  O env = NIL;
-  addroot(&env);
-  setupenv(&env);
-
-  // IF
-  O code = readfile(stdin);
-  addroot(&code);
-
-  // collect();
-  println(code);
-  printf("=> ");
-  println(eval(code, env));
-
-  gcfinalize();
-  return 0;
-}
diff --git a/old/object.c b/old/object.c
deleted file mode 100644
index b031c17..0000000
--- a/old/object.c
+++ /dev/null
@@ -1,103 +0,0 @@
-#include <inttypes.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "wscm.h"
-
-// clang-format off
-static const char *kindnames[] = {
-  [KIND_NIL] = "nil",
-  [KIND_NUM] = "number",
-  [KIND_SYM] = "symbol",
-  [KIND_PRIM] = "primitive",
-  [KIND_CONS] = "cons",
-  [KIND_CLOS] = "closure",
-};
-// clang-format on
-
-I kind(O obj) {
-  if (obj == NIL)
-    return KIND_NIL;
-  if (IMM(obj))
-    return KIND_NUM;
-
-  switch (TYPE(obj)) {
-  case TAG_SYM:
-    return KIND_SYM;
-  case TAG_PRIM:
-    return KIND_PRIM;
-  case TAG_GC: {
-    H *h = UNBOX(obj);
-    return h->type;
-  }
-  default:
-    fprintf(stderr, "unknown pointer tag %" PRIdPTR "\n", TYPE(obj));
-    abort();
-  }
-}
-
-const char *kindname(I k) {
-  if (k >= KIND__MAX)
-    return "??";
-  return kindnames[k];
-}
-
-// cons lists
-O cons(O head, O tail) {
-  I mark = rootmark();
-  addroot(&head);
-  addroot(&tail);
-
-  const Z sz = sizeof(H) + sizeof(C);
-  H *h = alloc(sz);
-  h->size = sz;
-  h->type = OBJ_CONS;
-
-  C *c = (C *)(h + 1);
-  c->car = head;
-  c->cdr = tail;
-
-  rootreset(mark);
-  return BOX(h);
-}
-
-C *uncons(O obj) {
-  I k = kind(obj);
-  if (k != KIND_CONS) {
-    fprintf(stderr, "expected cons, got %s\n", kindnames[k]);
-    abort();
-  }
-  H *h = UNBOX(obj);
-  return (C *)(h + 1);
-}
-
-// closures
-O mkclos(O args, O body, O env) {
-  I mark = rootmark();
-  addroot(&args);
-  addroot(&body);
-  addroot(&env);
-
-  const Z sz = sizeof(H) + sizeof(L);
-  H *h = alloc(sz);
-  h->size = sz;
-  h->type = OBJ_CLOS;
-
-  L *l = (L *)(h + 1);
-  l->args = args;
-  l->body = body;
-  l->env = env;
-
-  rootreset(mark);
-  return BOX(h);
-}
-
-L *unclos(O obj) {
-  I k = kind(obj);
-  if (k != KIND_CONS) {
-    fprintf(stderr, "expected closure, got %s\n", kindnames[k]);
-    abort();
-  }
-  H *h = UNBOX(obj);
-  return (L *)(h + 1);
-}
diff --git a/old/print.c b/old/print.c
deleted file mode 100644
index a22ae71..0000000
--- a/old/print.c
+++ /dev/null
@@ -1,71 +0,0 @@
-#include "wscm.h"
-
-#include <stdio.h>
-#include <inttypes.h>
-
-void print(O obj);
-
-static void printcons(O obj) {
-  O c = obj;
-  I f = 1;
-
-  printf("(");
-  while (c != NIL && !IMM(c)) {
-    H *h = UNBOX(c);
-    if (h->type != OBJ_CONS) {
-      printf(" . ");
-      print(c);
-      printf(")");
-      return;
-    }
-    C *p = (C *)(h + 1);
-    if (!f)
-      printf(" ");
-    f = 0;
-    print(p->car);
-    c = p->cdr;
-  }
-  if (c != NIL) {
-    printf(" . ");
-    print(c);
-  }
-  printf(")");
-}
-
-void print(O obj) {
-  if (obj == NIL) {
-    printf("()");
-  } else if (IMM(obj)) {
-    printf("%" PRIdPTR, ORD(obj));
-  } else {
-    void *x = (void *)UNBOX(obj);
-    switch (TYPE(obj)) {
-    case TAG_SYM: {
-      S *s = (S *)((U)x & ~7);
-      printf("%.*s", (int)s->len, s->data);
-      break;
-    }
-    case TAG_PRIM: {
-      P *p = (P *)((U)x & ~7);
-      printf("<#primitive %s>", p->name);
-      break;
-    }
-    default: {
-      H *h = (H *)x;
-      switch (h->type) {
-      case OBJ_CONS:
-        printcons(obj);
-        break;
-      default:
-        printf("<#obj type=%" PRIdPTR " @ %p>", h->type, (void *)h);
-        break;
-      }
-    }
-    }
-  }
-}
-
-void println(O obj) {
-  print(obj);
-  putchar('\n');
-}
diff --git a/old/read.c b/old/read.c
deleted file mode 100644
index 235cdde..0000000
--- a/old/read.c
+++ /dev/null
@@ -1,156 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "wscm.h"
-
-static O read(Lx *lex);
-
-static void skipcomments(Lx *lex) {
-  while (lex->kind == TOK_COMMENT) {
-    if (!nexttoken(lex))
-      break;
-  }
-}
-
-static O makeobject(Lx *lex) {
-  if (lex->kind == TOK_WORD) {
-    char *tok = lex->buffer;
-    char *end;
-    long v = strtol(tok, &end, 10);
-    if (end != tok && *end == '\0') {
-      nexttoken(lex);
-      return NUM((I)v);
-    } else {
-      S *s = intern(tok, (I)strlen(tok));
-      O sym = BOX(TAG(s, TAG_SYM));
-      nexttoken(lex);
-      return sym;
-    }
-  } else if (lex->kind == TOK_STRING) {
-    // TODO: string type
-    char *tok = lex->buffer;
-    S *s = intern(tok, (I)strlen(tok));
-    O sym = BOX(TAG(s, TAG_SYM));
-    nexttoken(lex);
-    return sym;
-  }
-  return NIL;
-}
-
-static void lastcdr(O list, O cdr_val) {
-  O curr = list;
-  while (1) {
-    C *c = uncons(curr);
-    if (c->cdr == NIL) {
-      c->cdr = cdr_val;
-      return;
-    }
-    curr = c->cdr;
-  }
-}
-
-static O readlist(Lx *lex) {
-  nexttoken(lex);
-  skipcomments(lex);
-
-  if (lex->kind == TOK_RPAREN) {
-    nexttoken(lex);
-    return NIL;
-  }
-
-  O head = NIL;
-  while (lex->kind != TOK_EOF) {
-    skipcomments(lex);
-    if (lex->kind == TOK_RPAREN) {
-      nexttoken(lex);
-      break;
-    }
-
-    if (lex->kind == TOK_DOT) {
-      nexttoken(lex);
-      skipcomments(lex);
-      if (lex->kind == TOK_EOF) {
-        fprintf(stderr, "reader error: unexpected EOF after '.'\n");
-        abort();
-      }
-      O cdr_val = read(lex);
-      skipcomments(lex);
-      if (lex->kind != TOK_RPAREN) {
-        fprintf(stderr, "reader error: expected ')' after dotted pair cdr\n");
-        abort();
-      }
-      nexttoken(lex);
-      O normal = listreverse(head);
-      if (normal == NIL) {
-        fprintf(stderr, "reader error: '.' with no preceding elements\n");
-        abort();
-      }
-      lastcdr(normal, cdr_val);
-      return normal;
-    }
-    O elem = read(lex);
-    head = cons(elem, head);
-    skipcomments(lex);
-  }
-
-  return listreverse(head);
-}
-
-static O readquote(Lx *lex) {
-  nexttoken(lex);
-  skipcomments(lex);
-  O e = read(lex);
-  O qsym = BOX(TAG(intern("quote", -1), TAG_SYM));
-  return cons(qsym, cons(e, NIL));
-}
-
-static O read(Lx *lex) {
-  skipcomments(lex);
-
-  switch (lex->kind) {
-  case TOK_EOF:
-    return NIL;
-  case TOK_LPAREN:
-    return readlist(lex);
-  case TOK_QUOTE:
-    return readquote(lex);
-  case TOK_WORD:
-  case TOK_STRING:
-    return makeobject(lex);
-  case TOK_COMMENT:
-    nexttoken(lex);
-    return read(lex);
-  default:
-    nexttoken(lex);
-    return NIL;
-  }
-}
-
-O readfile(FILE *f) {
-  if (!f)
-    return NIL;
-
-  Lx lex;
-  lex.kind = TOK_EOF;
-  lex.cursor = 0;
-  lex.input = f;
-  lex.buffer[0] = '\0';
-
-  nexttoken(&lex);
-  skipcomments(&lex);
-
-  if (lex.kind == TOK_EOF)
-    return NIL;
-  return read(&lex);
-}
-
-O readstring(const char *s) {
-  if (!s)
-    return NIL;
-  size_t len = strlen(s);
-  FILE *f = fmemopen((void *)s, len, "r");
-  O res = readfile(f);
-  fclose(f);
-  return res;
-}
diff --git a/old/symbol.c b/old/symbol.c
deleted file mode 100644
index c9c52a5..0000000
--- a/old/symbol.c
+++ /dev/null
@@ -1,81 +0,0 @@
-#include <stdlib.h>
-#include <string.h>
-
-#include "wscm.h"
-
-St syms = {0, 0, NULL};
-
-static S *findsym(const char *str, Z len, U32 hash) {
-  if (syms.capacity == 0)
-    return NULL;
-
-  Z ix = hash % syms.capacity;
-  for (Z i = 0; i < syms.capacity; i++) {
-    S *s = syms.data[ix];
-    if (!s)
-      return NULL;
-    if (s->hash == hash && s->len == len)
-      return s;
-    ix = (ix + 1) % syms.capacity;
-  }
-  return NULL;
-}
-
-static void symtabresize(void) {
-  Z cap = syms.capacity;
-  if (cap == 0) {
-    syms.capacity = 16;
-  } else {
-    syms.capacity *= 2;
-  }
-  S **nb = calloc(syms.capacity, sizeof(S *));
-  for (Z i = 0; i < cap; i++) {
-    if (syms.data[i]) {
-      S *s = syms.data[i];
-      Z ix = s->hash % syms.capacity;
-      while (nb[ix])
-        ix = (ix + 1) % syms.capacity;
-      nb[ix] = s;
-    }
-  }
-  if (syms.data != NULL)
-    free(syms.data);
-  syms.data = nb;
-}
-
-U32 hashstring(const char *data, I len) {
-  U32 hash = 2166136261u;
-  for (I i = 0; i < len; i++) {
-    hash ^= (uint8_t)data[i];
-    hash *= 16777619u;
-  }
-  return hash;
-}
-
-S *intern(const char *str, I len) {
-  if (len < 0)
-    len = strlen(str);
-
-  U32 hash = hashstring(str, len);
-  S *s = findsym(str, len, hash);
-  if (s)
-    return s;
-
-  s = malloc(sizeof(S));
-  s->data = malloc(len);
-  memcpy(s->data, str, len);
-  s->len = len;
-  s->hash = hash;
-
-  if (syms.count + 1 > syms.capacity)
-    symtabresize();
-
-  Z ix = hash % syms.capacity;
-  while (syms.data[ix])
-    ix = (ix + 1) % syms.capacity;
-
-  syms.data[ix] = s;
-  syms.count++;
-
-  return s;
-}
diff --git a/old/util.c b/old/util.c
deleted file mode 100644
index 55fd0ff..0000000
--- a/old/util.c
+++ /dev/null
@@ -1,16 +0,0 @@
-#include "wscm.h"
-
-O listreverse(O list) {
-  O prev = NIL;
-  O curr = list;
-  O next;
-
-  while (curr != NIL) {
-    C *c = uncons(curr);
-    next = c->cdr;
-    c->cdr = prev;
-    prev = curr;
-    curr = next;
-  }
-  return prev;
-}
diff --git a/old/wscm.h b/old/wscm.h
deleted file mode 100644
index 22b447a..0000000
--- a/old/wscm.h
+++ /dev/null
@@ -1,166 +0,0 @@
-#include <stddef.h>
-#include <stdint.h>
-
-// common types
-typedef void V;
-
-typedef uintptr_t U;
-typedef intptr_t I;
-
-typedef uint8_t U8;
-typedef uint32_t U32;
-typedef int32_t I32;
-typedef size_t Z;
-
-// objects
-typedef uintptr_t O;
-
-// cons pair
-typedef struct C C;
-struct C {
-  O car, cdr;
-};
-
-// lambda
-typedef struct L L;
-struct L {
-  O args, body, env;
-};
-
-// symbol
-typedef struct S S;
-struct S {
-  U8 *data;
-  U32 hash;
-  Z len;
-};
-
-// symbol table
-typedef struct St St;
-struct St {
-  I count;
-  Z capacity;
-  S **data;
-};
-
-#define TYPE_MASK 7
-
-enum {
-  TAG_GC = 0,   // GC-managed object
-  TAG_NUM = 1,  // Immediate number
-  TAG_SYM = 2,  // Pointer to symbol
-  TAG_PRIM = 4, // Pointer to primitive
-};
-
-enum {
-  KIND_NIL = 0,
-  KIND_NUM = 1,
-  KIND_SYM = 2,
-  KIND_PRIM = 4,
-  KIND_CONS = 5,
-  KIND_CLOS = 6,
-  KIND__MAX,
-};
-
-#define TYPE(x) (((U)(x)) & TYPE_MASK)
-#define UNTAG(x) (((U)(x)) & ~TYPE_MASK)
-#define TAG(x, t) (void *)(((U)(x)) | t)
-
-enum { OBJ_CONS = 5, OBJ_CLOS = 6, OBJ_FWD = 7 };
-
-// gc header
-typedef struct H H;
-struct H {
-  I type;
-  Z size;
-};
-
-// heap
-typedef struct E E;
-struct E {
-  struct {
-    U8 *start, *end;
-    U8 *free;
-  } from, to;
-
-  I root_count;
-  Z root_capacity;
-  O **roots;
-};
-
-// primitive
-typedef struct P P;
-struct P {
-  const char *name;
-  O (*fn)(O, O);
-};
-
-extern E heap;
-extern St syms;
-
-#define ALIGN(n) (((n) + 7) & ~7)
-#define INFROM(x)                                                              \
-  (((const U8 *)x) >= heap.from.start && ((const U8 *)x) < heap.from.end)
-
-#define IMM(x) ((x) & 1)
-#define NUM(x) (((O)((I)(x) << 1)) | (O)1)
-#define ORD(x) ((I)(x) >> 1)
-#define BOX(x) ((O)(x))
-#define UNBOX(x) ((H *)(x))
-
-#define SYM(s) BOX(TAG(intern(s, -1), TAG_SYM))
-
-#define NIL ((O)0)
-#define GC_HEAP_BYTES (1024 * 1024)
-
-// GC
-void addroot(O *ptr);
-I rootmark(void);
-void rootreset(I mark);
-void collect(void);
-H *alloc(Z sz);
-void gcinit(void);
-void gcfinalize(void);
-
-I kind(O obj);
-const char *kindname(I k);
-
-S *intern(const char *str, I len);
-O mksym(const char *str);
-
-O cons(O head, O tail);
-C *uncons(O obj);
-
-O listreverse(O list);
-
-V setupenv(O *env);
-O eval(O obj, O env);
-
-void print(O obj);
-void println(O obj);
-
-enum {
-	TOK_EOF = 0,
-	TOK_COMMENT = ';',
-	TOK_WORD = 'a',
-	TOK_LPAREN = '(',
-	TOK_RPAREN = ')',
-	TOK_STRING = '"',
-	TOK_QUOTE = '\'',
-	TOK_DOT = '.',
-};
-
-#include <stdio.h>
-
-#define LEXER_CAP 1024
-
-typedef struct Lx {
-	int kind;
-	int cursor;
-	FILE *input;
-	char buffer[1024];
-} Lx;
-
-int nexttoken(Lx *lex);
-O readfile(FILE *f);
-O readstring(const char *s);
diff --git a/shell.nix b/shell.nix
index fcf4e51..424ba43 100644
--- a/shell.nix
+++ b/shell.nix
@@ -2,6 +2,9 @@
 pkgs.mkShell {
   name = "rufus";
   packages = with pkgs; [
+    rlwrap
+    gemini-cli-bin
+    vscodium
     clang-tools
     meson
     ninja
diff --git a/src/interp.c b/src/interp.c
index a1f2a10..02497dd 100644
--- a/src/interp.c
+++ b/src/interp.c
@@ -133,8 +133,8 @@ static O apply(In *in, O fn, O args, O env) {
     Gh *hdr = UNBOX(fn);
     Cl *cl = (Cl *)(hdr + 1);
     O nenv = bind(in, cl->args, args, cl->env);
-    cl = (Cl *)(UNBOX(fn) +
-                1); // `bind' may have moved the closure if a GC was triggered
+    // `bind' may have moved the closure if a GC was triggered
+    cl = (Cl *)(UNBOX(fn) + 1);
     gc_rootreset(&in->gc, mark);
     return eval(in, cl->body, nenv);
   }