diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5ce98c8..b955dce 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,3 +9,25 @@ set(CMAKE_C_STANDARD          "11")
 add_compile_options(
   -Wall -Wextra -pedantic -Werror -Wno-missing-field-initializers
 )
+
+set(BINER_GENRATED_DIR "${CMAKE_CURRENT_BINARY_DIR}/generated")
+
+find_package(BISON REQUIRED)
+find_package(FLEX  REQUIRED)
+
+file(MAKE_DIRECTORY ${BINER_GENRATED_DIR})
+bison_target(biner-parser biner.y ${BINER_GENRATED_DIR}/biner.y.c)
+flex_target(biner-scanner biner.l ${BINER_GENRATED_DIR}/biner.l.c)
+add_flex_bison_dependency(biner-scanner biner-parser)
+
+add_executable(biner)
+target_sources(biner
+  PRIVATE
+    main.c
+    tree.c
+    ${BISON_biner-parser_OUTPUTS}
+    ${FLEX_biner-scanner_OUTPUTS}
+  PUBLIC
+    zone.h
+)
+target_include_directories(biner PRIVATE . ${CMAKE_CURRENT_BINARY_DIR})
diff --git a/TODO.TXT b/TODO.TXT
new file mode 100644
index 0000000..b21f012
--- /dev/null
+++ b/TODO.TXT
@@ -0,0 +1,8 @@
+X parser
+  error handling (compiler message)
+  expression resolving
+  enum support
+  union support
+  constant support
+  transpiler for C
+  release 1.0.0
diff --git a/biner.l b/biner.l
new file mode 100644
index 0000000..a149e97
--- /dev/null
+++ b/biner.l
@@ -0,0 +1,52 @@
+%option noinput nounput noyywrap
+
+%{
+
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include "./tree.h"
+#include "./zone.h"
+
+#include "generated/biner.y.h"
+
+#define ctx (biner_tree_parse_context_)
+
+static inline uintptr_t strnew_(const char* str) {
+  return biner_zone_strnew(&ctx.zone, str);
+}
+static inline intmax_t parse_int_(int base) {
+  char*          end = NULL;
+  const intmax_t v   = strtoimax(yytext, &end, base);
+
+  /* TODO: replace asserts with throwing error */
+  assert((v != INTMAX_MIN && v != INTMAX_MAX) || errno != ERANGE);
+  assert(INT64_MIN <= v && v <= INT64_MAX);
+  assert(end != NULL && *end == 0);
+
+  return v;
+}
+%}
+
+D [0-9]
+I [A-Za-z_]
+H [0-9A-Fa-f]
+
+%%
+
+"//".* ;
+[/][*][^*]*[*]+([^*/][^*]*[*]+)*[/] ; /* TODO: detect unterminated comment */
+
+"struct" return STRUCT;
+
+{I}({I}|{D})* { yylval.ptr = strnew_(yytext); return IDENT; }
+
+{D}+      { yylval.i = parse_int_(10); return INTEGER; }
+0[xX]{H}+ { yylval.i = parse_int_(16); return INTEGER; }
+
+[\+\-\*\/\.\(\)[\]\{\}\;] return yytext[0];
+
+(.|\n) ;
+
+%%
diff --git a/biner.y b/biner.y
new file mode 100644
index 0000000..473cabd
--- /dev/null
+++ b/biner.y
@@ -0,0 +1,213 @@
+%{
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "./tree.h"
+#include "./zone.h"
+
+#define ctx (biner_tree_parse_context_)
+
+#define alloc_(T)  (biner_zone_alloc(&ctx.zone, sizeof(T)))
+#define ref(T, p) ((T*) (ctx.zone.ptr+p))
+
+extern int  yylex(void);
+extern void yyerror(const char*);
+
+static inline biner_zone_ptr(biner_tree_struct_member_t)
+find_struct_member_(
+    biner_zone_ptr(biner_tree_struct_member_t) itr,
+    biner_zone_ptr(char)                       name) {
+  while (itr) {
+    const biner_tree_struct_member_t* m = ref(biner_tree_struct_member_t, itr);
+    if (strcmp(ref(char, m->name), ref(char, name)) == 0) {
+      return itr;
+    }
+    itr = m->prev;
+  }
+  yyerror("unknown member");
+  return 0;
+}
+%}
+
+%union {
+  int64_t   i;
+  uintptr_t ptr;
+}
+
+%token STRUCT
+%token <ptr> IDENT
+%token <i>   INTEGER;
+
+%type <ptr> decl_list decl
+%type <ptr> struct_body struct_member struct_member_type struct_member_reference
+%type <ptr> expr add_expr mul_expr operand
+
+%start decl_list
+
+%%
+
+decl_list
+  : decl {
+    *ref(biner_tree_root_t, ctx.root) = (biner_tree_root_t) {
+      .decls = $1,
+    };
+    $$ = ctx.root;
+  }
+  | decl_list decl {
+    ref(biner_tree_decl_t, $2)->prev  = ref(biner_tree_root_t, $1)->decls;
+    ref(biner_tree_root_t, $1)->decls = $2;
+    $$ = $1;
+  }
+  ;
+
+decl
+  : STRUCT IDENT '{' struct_body '}' ';' {
+    $$ = alloc_(biner_tree_decl_t);
+    *ref(biner_tree_decl_t, $$) = (biner_tree_decl_t) {
+      .name   = $2,
+      .member = $4,
+    };
+    ctx.last_decl   = $$;
+    ctx.last_member = 0;
+  }
+  ;
+
+struct_body
+  : struct_member {
+    $$ = ctx.last_member = $1;
+  }
+  | struct_body struct_member {
+    ref(biner_tree_struct_member_t, $2)->prev = $1;
+    $$ = ctx.last_member = $2;
+  }
+  ;
+
+struct_member
+  : struct_member_type IDENT ';' {
+    $$ = alloc_(biner_tree_struct_member_t);
+    *ref(biner_tree_struct_member_t, $$) =
+      (biner_tree_struct_member_t) {
+        .type = $1,
+        .name = $2,
+      };
+  }
+  ;
+
+struct_member_type
+  : IDENT {
+    /* TODO: upgrade generic type to user-defined type. */
+    $$ = alloc_(biner_tree_struct_member_type_t);
+    *ref(biner_tree_struct_member_type_t, $$) =
+      (biner_tree_struct_member_type_t) {
+        .kind      = BINER_TREE_STRUCT_MEMBER_TYPE_KIND_GENERIC,
+        .generic   = $1,
+        .qualifier = BINER_TREE_STRUCT_MEMBER_TYPE_QUALIFIER_NONE,
+      };
+  }
+  | IDENT '[' expr ']' {
+    $$ = alloc_(biner_tree_struct_member_type_t);
+    *ref(biner_tree_struct_member_type_t, $$) =
+      (biner_tree_struct_member_type_t) {
+        .kind      = BINER_TREE_STRUCT_MEMBER_TYPE_KIND_GENERIC,
+        .generic      = $1,
+        .qualifier = BINER_TREE_STRUCT_MEMBER_TYPE_QUALIFIER_DYNAMIC_ARRAY,
+        .expr      = $3,
+      };
+  }
+  ;
+
+expr
+  : add_expr { $$ = $1; }
+  ;
+
+add_expr
+  : mul_expr
+  | add_expr '+' mul_expr {
+    $$ = alloc_(biner_tree_expr_t);
+    *ref(biner_tree_expr_t, $$) = (biner_tree_expr_t) {
+      .type     = BINER_TREE_EXPR_TYPE_OPERATOR_ADD,
+      .operands = {$1, $3},
+    };
+  }
+  | add_expr '-' mul_expr {
+    $$ = alloc_(biner_tree_expr_t);
+    *ref(biner_tree_expr_t, $$) = (biner_tree_expr_t) {
+      .type     = BINER_TREE_EXPR_TYPE_OPERATOR_SUB,
+      .operands = {$1, $3},
+    };
+  }
+  ;
+
+mul_expr
+  : operand
+  | mul_expr '*' operand {
+    $$ = alloc_(biner_tree_expr_t);
+    *ref(biner_tree_expr_t, $$) = (biner_tree_expr_t) {
+      .type     = BINER_TREE_EXPR_TYPE_OPERATOR_MUL,
+      .operands = {$1, $3},
+    };
+  }
+  | mul_expr '/' operand {
+    $$ = alloc_(biner_tree_expr_t);
+    *ref(biner_tree_expr_t, $$) = (biner_tree_expr_t) {
+      .type     = BINER_TREE_EXPR_TYPE_OPERATOR_DIV,
+      .operands = {$1, $3},
+    };
+  }
+  ;
+
+operand
+  : INTEGER {
+    $$ = alloc_(biner_tree_expr_t);
+    *ref(biner_tree_expr_t, $$) = (biner_tree_expr_t) {
+      .type = BINER_TREE_EXPR_TYPE_OPERAND_INTEGER,
+      .i    = $1,
+    };
+  }
+  | struct_member_reference {
+    $$ = alloc_(biner_tree_expr_t);
+    *ref(biner_tree_expr_t, $$) = (biner_tree_expr_t) {
+      .type = BINER_TREE_EXPR_TYPE_OPERAND_REFER,
+      .r    = $1,
+    };
+  }
+  | '(' expr ')' { $$ = $2; }
+  ;
+
+struct_member_reference
+  : IDENT {
+    $$ = alloc_(biner_tree_struct_member_reference_t);
+    *ref(biner_tree_struct_member_reference_t, $$) =
+      (biner_tree_struct_member_reference_t) {
+        .member = find_struct_member_(ctx.last_member, $1),
+      };
+  }
+  | struct_member_reference '.' IDENT {
+    const biner_tree_struct_member_t* p =
+      ref(biner_tree_struct_member_t, $1);
+
+    const biner_tree_struct_member_type_t* t =
+      ref(biner_tree_struct_member_type_t, p->type);
+    if (t->kind != BINER_TREE_STRUCT_MEMBER_TYPE_KIND_USER_DEFINED) {
+      yyerror("not user-defined data");
+      YYABORT;
+    }
+
+    const biner_tree_decl_t* d = ref(biner_tree_decl_t, t->decl);
+    if (d->type != BINER_TREE_DECL_TYPE_STRUCT) {
+      yyerror("not struct");
+      YYABORT;
+    }
+    $$ = alloc_(biner_tree_struct_member_reference_t);
+    *ref(biner_tree_struct_member_reference_t, $$) =
+      (biner_tree_struct_member_reference_t) {
+        .member = find_struct_member_(d->member, $3),
+      };
+  }
+  ;
+
+%%
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..bd60d22
--- /dev/null
+++ b/main.c
@@ -0,0 +1,27 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "./tree.h"
+
+int main(void) {
+  const uint8_t* zone = biner_tree_parse(stdin);
+  if (zone == NULL) return EXIT_FAILURE;
+
+  const biner_tree_root_t* root = (const biner_tree_root_t*) zone;
+
+  const biner_tree_decl_t* decl =
+    (const biner_tree_decl_t*) (zone + root->decls);
+  while ((uintptr_t) decl != (uintptr_t) zone) {
+    printf("%s:\n", zone + decl->name);
+
+    const biner_tree_struct_member_t* member =
+      (const biner_tree_struct_member_t*) (zone + decl->member);
+    while ((uintptr_t) member != (uintptr_t) zone) {
+      printf("  %s\n", zone + member->name);
+      member = (const biner_tree_struct_member_t*) (zone + member->prev);
+    }
+    decl = (const biner_tree_decl_t*) (zone + decl->prev);
+  }
+  return EXIT_SUCCESS;
+}
diff --git a/tree.c b/tree.c
new file mode 100644
index 0000000..ac5c848
--- /dev/null
+++ b/tree.c
@@ -0,0 +1,36 @@
+#include "./tree.h"
+
+#include <assert.h>
+#include <stdatomic.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "./zone.h"
+
+#include "generated/biner.y.h"
+
+biner_tree_parse_context_t biner_tree_parse_context_ = {0};
+
+int yyerror(char* str) {
+  extern char* yytext;
+  fprintf(stderr, "error: %s: %s\n", str, yytext);
+  return 0;
+}
+
+const uint8_t* biner_tree_parse(FILE* fp) {
+  if (atomic_flag_test_and_set(&biner_tree_parse_context_.dirty)) {
+    fprintf(stderr, "parsing context is dirty now\n");
+    abort();
+  }
+
+  extern FILE* yyin;
+  yyin = fp;
+
+  biner_tree_parse_context_.root = biner_zone_alloc(
+    &biner_tree_parse_context_.zone, sizeof(biner_tree_root_t));
+  assert(biner_tree_parse_context_.root == 0);
+  return yyparse()? NULL: biner_tree_parse_context_.zone.ptr;
+}
diff --git a/tree.h b/tree.h
new file mode 100644
index 0000000..2ffea9c
--- /dev/null
+++ b/tree.h
@@ -0,0 +1,107 @@
+#pragma once
+
+#include <stdatomic.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include "./zone.h"
+
+typedef struct biner_tree_expr_t                    biner_tree_expr_t;
+typedef struct biner_tree_struct_member_t           biner_tree_struct_member_t;
+typedef struct biner_tree_struct_member_reference_t biner_tree_struct_member_reference_t;
+typedef struct biner_tree_struct_t                  biner_tree_struct_t;
+typedef struct biner_tree_decl_t                    biner_tree_decl_t;
+
+typedef enum biner_tree_expr_type_t {
+  BINER_TREE_EXPR_TYPE_OPERAND_INTEGER,
+  BINER_TREE_EXPR_TYPE_OPERAND_REFER,
+  BINER_TREE_EXPR_TYPE_OPERATOR_ADD,
+  BINER_TREE_EXPR_TYPE_OPERATOR_SUB,
+  BINER_TREE_EXPR_TYPE_OPERATOR_MUL,
+  BINER_TREE_EXPR_TYPE_OPERATOR_DIV,
+} biner_tree_expr_type_t;
+
+typedef struct biner_tree_expr_t {
+  biner_tree_expr_type_t type;
+  union {
+    int64_t i;
+    biner_zone_ptr(biner_tree_struct_member_reference_t) r;
+    struct {
+      biner_zone_ptr(biner_tree_expr_t) l;
+      biner_zone_ptr(biner_tree_expr_t) r;
+    } operands;
+  };
+} biner_tree_expr_t;
+
+typedef enum biner_tree_struct_member_type_kind_t {
+  BINER_TREE_STRUCT_MEMBER_TYPE_KIND_GENERIC,
+  BINER_TREE_STRUCT_MEMBER_TYPE_KIND_USER_DEFINED,
+} biner_tree_struct_member_type_kind_t;
+
+typedef enum biner_tree_struct_member_type_qualifier_t {
+  BINER_TREE_STRUCT_MEMBER_TYPE_QUALIFIER_NONE,
+  BINER_TREE_STRUCT_MEMBER_TYPE_QUALIFIER_STATIC_ARRAY,
+  BINER_TREE_STRUCT_MEMBER_TYPE_QUALIFIER_DYNAMIC_ARRAY,
+} biner_tree_struct_member_type_qualifier_t;
+
+typedef struct biner_tree_struct_member_type_t {
+  biner_tree_struct_member_type_kind_t kind;
+  union {
+    biner_zone_ptr(char)              generic;
+    biner_zone_ptr(biner_tree_decl_t) decl;
+  };
+
+  biner_tree_struct_member_type_qualifier_t qualifier;
+  union {
+    size_t i;
+    biner_zone_ptr(biner_tree_expr_t) expr;
+  };
+} biner_tree_struct_member_type_t;
+
+typedef struct biner_tree_struct_member_t {
+  biner_zone_ptr(char)                            name;
+  biner_zone_ptr(biner_tree_struct_t)             owner;
+  biner_zone_ptr(biner_tree_struct_member_type_t) type;
+
+  biner_zone_ptr(biner_tree_struct_member_t) prev;
+} biner_tree_struct_member_t;
+
+typedef struct biner_tree_struct_member_reference_t {
+  biner_zone_ptr(biner_tree_struct_member_t)           member;
+  biner_zone_ptr(biner_tree_expr_t)                    index;
+  biner_zone_ptr(biner_tree_struct_member_reference_t) prev;
+} biner_tree_struct_member_reference_t;
+
+typedef enum biner_tree_decl_type_t {
+  BINER_TREE_DECL_TYPE_STRUCT,
+} biner_tree_decl_type_t;
+
+typedef struct biner_tree_decl_t {
+  biner_zone_ptr(char) name;
+  biner_tree_decl_type_t type;
+  union {
+    biner_zone_ptr(biner_tree_struct_member_t) member;
+  };
+  biner_zone_ptr(biner_tree_decl_t) prev;
+} biner_tree_decl_t;
+
+typedef struct biner_tree_root_t {
+  biner_zone_ptr(biner_tree_decl_t) decls;
+} biner_tree_root_t;
+
+typedef struct biner_tree_parse_context_t {
+  atomic_flag  dirty;
+  biner_zone_t zone;
+
+  biner_zone_ptr(biner_tree_root_t)          root;
+  biner_zone_ptr(biner_tree_decl_t)          last_decl;
+  biner_zone_ptr(biner_tree_struct_member_t) last_member;
+} biner_tree_parse_context_t;
+
+extern biner_tree_parse_context_t biner_tree_parse_context_;
+
+const uint8_t*
+biner_tree_parse(
+  FILE* fp
+);
diff --git a/zone.h b/zone.h
new file mode 100644
index 0000000..b0294a1
--- /dev/null
+++ b/zone.h
@@ -0,0 +1,52 @@
+#pragma once
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define biner_zone_ptr(T) uintptr_t
+
+typedef struct biner_zone_t {
+  uintptr_t tail;
+  size_t    size;
+  uint8_t*  ptr;
+} biner_zone_t;
+
+#define BINER_ZONE_RESERVE 1024
+
+static inline uintptr_t biner_zone_alloc(biner_zone_t* z, size_t sz) {
+  assert(z != NULL);
+  assert(sz > 0);
+
+  if (z->ptr == NULL) {
+    z->ptr = calloc(1, sz);
+    if (z->ptr == NULL) {
+      fprintf(stderr, "malloc failure\n");
+      abort();
+    }
+  }
+  const uintptr_t oldtail = z->tail;
+  z->tail += sz;
+  if (z->tail > z->size) {
+    z->size = z->tail;
+    z->ptr  = realloc(z->ptr, z->size);
+  }
+  memset(z->ptr+oldtail, 0, sz);
+  return oldtail;
+}
+
+static inline uintptr_t biner_zone_strnew(biner_zone_t* z, const char* str) {
+  assert(z != NULL);
+
+  const uintptr_t ret = biner_zone_alloc(z, strlen(str)+1);
+  strcpy((char*) (z->ptr+ret), str);
+  return ret;
+}
+
+static inline void biner_zone_deinitialize(biner_zone_t* z) {
+  assert(z != NULL);
+
+  if (z->ptr != NULL) free(z->ptr);
+}