diff --git a/Cargo.toml b/Cargo.toml
index bbe1508..6efe945 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,3 +11,9 @@ cc = "1.0"
 
 [dependencies]
 yutil = { package = "util", git = "https://git.yukiri.dev/Yukiri/util.git" }
+
+[profile.dev]
+opt-level = 0
+
+[profile.release]
+opt-level = 3
diff --git a/src/interface/allocate.rs b/src/interface/allocate.rs
deleted file mode 100644
index 9036f50..0000000
--- a/src/interface/allocate.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-use crate::runtime;
-
-pub fn new(t:u32) -> usize { unsafe { runtime::acquire(t) } }
-pub fn address(id:usize) -> runtime::Variable { unsafe { runtime::address(id) } }
-pub fn delete(id:usize) -> bool { unsafe { runtime::release(id) } }
diff --git a/src/interface/array.rs b/src/interface/array.rs
new file mode 100644
index 0000000..687f80d
--- /dev/null
+++ b/src/interface/array.rs
@@ -0,0 +1,47 @@
+use crate::runtime::{
+    Variable,
+    acquire, release,
+    array_length, array_get, array_set
+};
+use super::{Type, array};
+
+pub struct Array {
+    managed:bool,
+    addr:Variable,
+}
+impl Array {
+    pub fn new(size:usize, class:usize) -> Self
+    {
+        Self {
+            managed:true,
+            addr:unsafe {acquire(array(size, class))},
+        }
+    }
+
+    pub fn from(addr:Variable) -> Self
+    {
+        Self { managed:false, addr:addr }
+    }
+
+    pub fn length(&self) -> usize
+    {
+        unsafe {array_length(self.addr)}
+    }
+
+    pub fn set(&mut self, index:usize, source:Variable)
+    {
+        unsafe { array_set(self.addr, index, source); }
+    }
+
+    pub fn get(&self, index:usize) -> Type
+    {
+        Type::from(unsafe {array_get(self.addr, index)})
+    }
+}
+impl std::ops::Deref for Array {
+    type Target = Variable;
+    fn deref(&self) -> &Self::Target { return &self.addr; }
+}
+impl Drop for Array {
+    fn drop(&mut self) { if self.managed { unsafe {release(self.addr)}; } }
+}
diff --git a/src/interface/block.rs b/src/interface/block.rs
new file mode 100644
index 0000000..255fbe9
--- /dev/null
+++ b/src/interface/block.rs
@@ -0,0 +1,49 @@
+use crate::runtime::{Variable, acquire, release, type_inner, type_key, block_set, block_get};
+use super::block;
+
+pub struct Block {
+    managed:bool,
+    addr:Variable,
+}
+impl Block {
+    pub fn new(size:usize) -> Self
+    {
+        Self {
+            managed:true,
+            addr:unsafe {acquire(block(size))},
+        }
+    }
+
+    pub fn from(addr:Variable) -> Self
+    {
+        Self { managed:false, addr:addr }
+    }
+
+    pub fn set(&mut self, data:Vec<u8>)
+    {
+        let length = unsafe {type_key(type_inner(self.addr.class))};
+        for index in 0..usize::min(data.len(), length) {
+            unsafe {block_set(self.addr, index, data[index])};
+        }
+    }
+
+    pub fn get(&self) -> Vec<u8>
+    {
+        let mut result = Vec::<u8>::new();
+        let length = unsafe {type_key(type_inner(self.addr.class))};
+        if length > 0 {
+            result.resize(length, 0);
+            for index in 0..length {
+                result[index] = unsafe {block_get(self.addr, index)};
+            }
+        }
+        return result;
+    }
+}
+impl std::ops::Deref for Block {
+    type Target = Variable;
+    fn deref(&self) -> &Self::Target { return &self.addr; }
+}
+impl Drop for Block {
+    fn drop(&mut self) { if self.managed { unsafe {release(self.addr)}; } }
+}
diff --git a/src/interface/boolean.rs b/src/interface/boolean.rs
index ea20865..18e1040 100644
--- a/src/interface/boolean.rs
+++ b/src/interface/boolean.rs
@@ -1,5 +1,5 @@
-use crate::runtime::{Variable, bool_get, bool_set};
-use crate::interface::{ allocate::*, builder::* };
+use crate::runtime::{Variable, acquire, release, bool_get, bool_set};
+use super::boolean;
 
 pub struct Boolean {
     managed:bool,
@@ -9,30 +9,38 @@ pub struct Boolean {
 impl Boolean {
     pub fn new() -> Self
     {
-        let t = boolean();
         Self {
             managed:true,
-            addr:Variable { class:t as usize, address: new(t) },
+            addr:unsafe {acquire(boolean())},
         }
     }
 
+    pub fn from(addr:Variable) -> Self
+    {
+        Self { managed:false, addr:addr }
+    }
+
+    pub fn with(value:bool) -> Self
+    {
+        let mut obj = Self::new();
+        obj.set(value);
+        return obj;
+    }
+
     pub fn set(&mut self, value:bool)
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { bool_set(mem, value) };
+        unsafe { bool_set(self.addr, value) };
     }
 
     pub fn get(&self) -> bool
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { bool_get(mem) }
+        unsafe { bool_get(self.addr) }
     }
 }
-
+impl std::ops::Deref for Boolean {
+    type Target = Variable;
+    fn deref(&self) -> &Self::Target { return &self.addr; }
+}
 impl Drop for Boolean {
-    fn drop(&mut self) {
-        if self.managed {
-            delete(self.addr.address);
-        }
-    }
+    fn drop(&mut self) { if self.managed { unsafe {release(self.addr)}; } }
 }
diff --git a/src/interface/builder.rs b/src/interface/builder.rs
index 2846324..f94a674 100644
--- a/src/interface/builder.rs
+++ b/src/interface/builder.rs
@@ -1,13 +1,24 @@
 use crate::tag;
 use crate::runtime;
 
-pub fn varying() -> u32 { 0 }
-pub fn null() -> u32 { unsafe { runtime::type_outer(0, tag::NULL) } }
-pub fn boolean() -> u32 { unsafe { runtime::type_outer(0, tag::BOOLEAN) } }
-pub fn natural() -> u32 { unsafe { runtime::type_outer(0, tag::NATURAL) } }
-pub fn integer() -> u32 { unsafe { runtime::type_outer(0, tag::INTEGER) } }
-pub fn array(s:u32, t:u32) -> u32 {
-    let size_node = unsafe { runtime::type_outer(t, s) };
-    unsafe { runtime::type_outer(size_node, tag::ARRAY) }
+pub fn varying() -> usize { 0 }
+pub fn null() -> usize { unsafe { runtime::type_outer(0, tag::NULL) } }
+pub fn boolean() -> usize { unsafe { runtime::type_outer(0, tag::BOOLEAN) } }
+pub fn natural() -> usize { unsafe { runtime::type_outer(0, tag::NATURAL) } }
+pub fn integer() -> usize { unsafe { runtime::type_outer(0, tag::INTEGER) } }
+
+pub fn block(size:usize) -> usize {
+    unsafe {
+        let inner_node = runtime::type_outer(0, size);
+        runtime::type_outer(inner_node, tag::BLOCK)
+    }
 }
-pub fn list(t:u32) -> u32 { unsafe { runtime::type_outer(t, tag::LIST) } }
+
+pub fn array(size:usize, type_id:usize) -> usize {
+    unsafe {
+        let inner_node = runtime::type_outer(type_id, size);
+        runtime::type_outer(inner_node, tag::ARRAY)
+    }
+}
+
+pub fn list(type_id:usize) -> usize { unsafe { runtime::type_outer(type_id, tag::LIST) } }
diff --git a/src/interface/integer.rs b/src/interface/integer.rs
index d02abf3..f517400 100644
--- a/src/interface/integer.rs
+++ b/src/interface/integer.rs
@@ -1,38 +1,45 @@
-use crate::runtime::{Variable, integer_get, integer_set};
-use crate::interface::{ allocate::*, builder::* };
+use crate::runtime::{Variable, acquire, release, integer_get, integer_set};
+use super::integer;
 
 pub struct Integer {
     managed:bool,
     addr:Variable,
 }
-
 impl Integer {
     pub fn new() -> Self
     {
-        let t = integer();
         Self {
             managed:true,
-            addr:Variable { class:t as usize, address: new(t) },
+            addr:unsafe {acquire(integer())},
         }
     }
 
+    pub fn from(addr:Variable) -> Self
+    {
+        Self { managed:false, addr:addr }
+    }
+
+    pub fn with(value:i64) -> Self
+    {
+        let mut obj = Self::new();
+        obj.set(value);
+        return obj;
+    }
+
     pub fn set(&mut self, value:i64)
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { integer_set(mem, value) };
+        unsafe { integer_set(self.addr, value) };
     }
 
     pub fn get(&self) -> i64
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { integer_get(mem) }
+        unsafe { integer_get(self.addr) }
     }
 }
-
+impl std::ops::Deref for Integer {
+    type Target = Variable;
+    fn deref(&self) -> &Self::Target { return &self.addr; }
+}
 impl Drop for Integer {
-    fn drop(&mut self) {
-        if self.managed {
-            delete(self.addr.address);
-        }
-    }
+    fn drop(&mut self) { if self.managed { unsafe {release(self.addr)}; } }
 }
diff --git a/src/interface/list.rs b/src/interface/list.rs
index bc84205..6ad1ac3 100644
--- a/src/interface/list.rs
+++ b/src/interface/list.rs
@@ -1,50 +1,86 @@
-use crate::runtime::Variable;
-use crate::interface::{ allocate::*, builder::* };
+use crate::runtime::{
+    Variable,
+    acquire, release,
+    list_capacity, list_length,
+    list_at,
+    list_clear,
+    list_insert, list_update,
+    list_remove,
+    list_reserve,
+};
+use super::{varying, list};
 
 pub struct List {
     managed:bool,
     addr:Variable,
 }
-
 impl List {
-    pub fn new(t:u32) -> Self
+    pub fn new(class:usize) -> Self
     {
-        let t = list(t);
         Self {
             managed:true,
-            addr:Variable { class:t as usize, address: new(t) },
+            addr:unsafe {acquire(list(class))},
         }
     }
 
-    pub fn capacity(&mut self) -> usize
+    pub fn from(addr:Variable) -> Self
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { list_capacity(mem) };
+        Self { managed:false, addr:addr }
     }
 
-    pub fn length(&mut self) -> usize
+    pub fn with(data:Vec<Variable>) -> Self
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { list_length(mem) };
+        let mut obj = Self::new(varying());
+        for item in data {
+            obj.insert(obj.length(), item);
+        }
+        return obj;
     }
 
-    pub fn at(&mut self, index:usize) -> Variable
+    pub fn capacity(&self) -> usize
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { list_at(mem, index) };
+        unsafe {list_capacity(self.addr)}
     }
 
-    pub fn capacity(&mut self)
+    pub fn length(&self) -> usize
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { list_capacity(mem) };
+        unsafe {list_length(self.addr)}
+    }
+
+    pub fn at(&self, index:usize) -> Variable
+    {
+        unsafe {list_at(self.addr, index)}
+    }
+
+    pub fn clear(&mut self)
+    {
+        unsafe{list_clear(self.addr)};
+    }
+
+    pub fn insert(&mut self, index:usize, source:Variable)
+    {
+        unsafe{list_insert(self.addr, index, source)};
+    }
+
+    pub fn update(&mut self, index:usize, source:Variable)
+    {
+        unsafe{list_update(self.addr, index, source)};
+    }
+
+    pub fn remove(&mut self, index:usize, maximum:usize)
+    {
+        unsafe{list_remove(self.addr, index, maximum)};
+    }
+
+    pub fn reserve(&mut self, length:usize)
+    {
+        unsafe{list_reserve(self.addr, length)};
     }
 }
-
+impl std::ops::Deref for List {
+    type Target = Variable;
+    fn deref(&self) -> &Self::Target { return &self.addr; }
+}
 impl Drop for List {
-    fn drop(&mut self) {
-        if self.managed {
-            delete(self.addr.address);
-        }
-    }
+    fn drop(&mut self) { if self.managed { unsafe {release(self.addr)}; } }
 }
diff --git a/src/interface/mod.rs b/src/interface/mod.rs
index e5d76ba..98d59e1 100644
--- a/src/interface/mod.rs
+++ b/src/interface/mod.rs
@@ -1,15 +1,37 @@
+use crate::runtime::{Variable, type_key};
+use crate::tag;
+
 mod builder; pub use builder::*;
-mod allocate; pub use allocate::*;
-mod util; pub use util::*;
 
 mod boolean; pub use boolean::Boolean;
 mod natural; pub use natural::Natural;
 mod integer; pub use integer::Integer;
+mod block; pub use block::Block;
+mod array; pub use array::Array;
+mod list; pub use list::List;
 
-enum Type {
+pub enum Type {
+    Varying,
     Null,
     Boolean(Boolean),
     Natural(Natural),
     Integer(Integer),
-    List,
+    Block(Block),
+    Array(Array),
+    List(List),
+}
+impl Type {
+    pub fn from(addr:Variable) -> Self
+    {
+        match unsafe {type_key(addr.class)} {
+            tag::VARYING => Type::Varying,
+            tag::NULL => Type::Null,
+            tag::BOOLEAN => Type::Boolean(Boolean::from(addr)),
+            tag::NATURAL => Type::Natural(Natural::from(addr)),
+            tag::INTEGER => Type::Integer(Integer::from(addr)),
+            tag::ARRAY => Type::Array(Array::from(addr)),
+            //tag::LIST => Type::List(List::from(addr)),
+            _ => Type::Null,
+        }
+    }
 }
diff --git a/src/interface/natural.rs b/src/interface/natural.rs
index 1415b37..4e85cc1 100644
--- a/src/interface/natural.rs
+++ b/src/interface/natural.rs
@@ -1,38 +1,45 @@
-use crate::runtime::{Variable, natural_get, natural_set};
-use crate::interface::{ allocate::*, builder::* };
+use crate::runtime::{Variable, acquire, release, natural_get, natural_set};
+use super::natural;
 
 pub struct Natural {
     managed:bool,
     addr:Variable,
 }
-
 impl Natural {
     pub fn new() -> Self
     {
-        let t = natural();
         Self {
             managed:true,
-            addr:Variable { class:t as usize, address: new(t) },
+            addr:unsafe {acquire(natural())},
         }
     }
 
+    pub fn from(addr:Variable) -> Self
+    {
+        Self { managed:false, addr:addr }
+    }
+
+    pub fn with(value:u64) -> Self
+    {
+        let mut obj = Self::new();
+        obj.set(value);
+        return obj;
+    }
+
     pub fn set(&mut self, value:u64)
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { natural_set(mem, value) };
+        unsafe { natural_set(self.addr, value) };
     }
 
     pub fn get(&self) -> u64
     {
-        let mem = if self.managed { address(self.addr.address) } else { self.addr };
-        unsafe { natural_get(mem) }
+        unsafe { natural_get(self.addr) }
     }
 }
-
+impl std::ops::Deref for Natural {
+    type Target = Variable;
+    fn deref(&self) -> &Self::Target { return &self.addr; }
+}
 impl Drop for Natural {
-    fn drop(&mut self) {
-        if self.managed {
-            delete(self.addr.address);
-        }
-    }
+    fn drop(&mut self) { if self.managed { unsafe {release(self.addr)}; } }
 }
diff --git a/src/interface/util.rs b/src/interface/util.rs
deleted file mode 100644
index ceb44f8..0000000
--- a/src/interface/util.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-use crate::runtime;
-
-pub fn get_type(t:u32) -> u32 { unsafe { runtime::type_key(t)} }
-pub fn get_inner(t:u32) -> u32 { unsafe { runtime::type_inner(t)} }
diff --git a/src/interface/varying.rs b/src/interface/varying.rs
index 19fc618..4c5f3a0 100644
--- a/src/interface/varying.rs
+++ b/src/interface/varying.rs
@@ -1,24 +1,35 @@
-struct Varying {
-    addr:usize,
+use crate::runtime::{Variable, acquire, release, bool_get, bool_set};
+use super::varying;
+
+pub struct Boolean {
+    managed:bool,
+    addr:Variable,
 }
+
 impl Varying {
     pub fn new() -> Self
+    {
+        Self {
+            managed:true,
+            addr:unsafe {acquire(varying())},
+        }
+    }
+
+    pub fn set(&mut self, value:bool)
     {
         
     }
-    
-    pub fn set()
+
+    pub fn get(&self) -> Variable
     {
-
-    }
-
-    pub fn class()
-    {
-
-    }
-
-    pub fn get()
-    {
-
+        false
+    }
+}
+
+impl Drop for Varying {
+    fn drop(&mut self) {
+        if self.managed {
+            unsafe {release(self.addr)};
+        }
     }
 }
diff --git a/src/runtime/lib.cc b/src/runtime/lib.cc
index fed8ecd..5f61825 100644
--- a/src/runtime/lib.cc
+++ b/src/runtime/lib.cc
@@ -4,25 +4,25 @@ TypeTree DB_TYPE;
 NameTree DB_NAME;
 Pool<Variable> DB_DATA;
 
-extern "C" uint32_t type_outer(uint32_t id, uint32_t key)
+extern "C" size_t type_outer(size_t type_id, size_t key)
 {
-    return DB_TYPE.outer(id, key);
+    return DB_TYPE.outer(type_id, key);
 }
 
-extern "C" uint32_t type_inner(uint32_t id)
+extern "C" size_t type_inner(size_t type_id)
 {
-    return DB_TYPE.inner(id);
+    return DB_TYPE.inner(type_id);
 }
 
-extern "C" uint32_t type_key(uint32_t id)
+extern "C" size_t type_key(size_t type_id)
 {
-    return DB_TYPE.value(id);
+    return DB_TYPE.key(type_id);
 }
 
-extern "C" size_t type_size(uint32_t type_id)
+extern "C" size_t type_size(size_t type_id)
 {
     if(DB_TYPE.has(type_id)) {
-        uint32_t type = DB_TYPE.value(type_id);
+        size_t type = DB_TYPE.key(type_id);
 
         switch(type) {
             case Type::Tag::Varying: return sizeof(Variable);
@@ -30,11 +30,12 @@ extern "C" size_t type_size(uint32_t type_id)
             case Type::Tag::Boolean: return sizeof(Type::Boolean);
             case Type::Tag::Natural: return sizeof(Type::Natural);
             case Type::Tag::Integer: return sizeof(Type::Integer);
-            case Type::Tag::Block:   return DB_TYPE.value(DB_TYPE.inner(type_id));
+            case Type::Tag::Block:   return DB_TYPE.key(DB_TYPE.inner(type_id));
             case Type::Tag::String:  return sizeof(Type::List);
             case Type::Tag::Array: {
-                uint32_t inner = static_cast<uint32_t>(DB_TYPE.inner(type_id));
-                return static_cast<size_t>(DB_TYPE.value(inner)) * type_size(static_cast<uint32_t>(DB_TYPE.inner(inner)));
+                size_t length = DB_TYPE.inner(type_id);
+                size_t inner = DB_TYPE.inner(length);
+                return static_cast<size_t>(DB_TYPE.key(length)) * type_size(inner);
             };
             case Type::Tag::List:    return sizeof(Type::List);
             default: return 0;
@@ -43,7 +44,7 @@ extern "C" size_t type_size(uint32_t type_id)
     return 0;
 }
 
-void* allocate(uint32_t type_id, size_t count)
+void* allocate(size_t type_id, size_t count)
 {
     void* mem = nullptr;
     size_t size = type_size(type_id) * count;
@@ -57,40 +58,55 @@ void* allocate(uint32_t type_id, size_t count)
     return nullptr;
 }
 
-extern "C" size_t acquire(uint32_t type_id)
+extern "C" Variable acquire(size_t type_id)
 {
-    void* mem = allocate(type_id, 1);
     Variable addr {0};
-    if(mem != nullptr) {
+    addr.address = allocate(type_id, 1);
+    if(addr.address != nullptr) {
         addr.type = type_id;
-        addr.address = mem;
-        return DB_DATA.add(addr);
-    }
-    return 0;
- }
-
-extern "C" bool release(size_t id)
-{
-    if(DB_DATA.has(id)) {
-        Variable addr;
-        if(DB_DATA.get(id, addr)) {
-            if(addr.address != nullptr) {
-                free(addr.address);
-            }
-            DB_DATA.remove(id);
-            return true;
-        }
-    }
-    return false;
-}
-
-extern "C" Variable address(size_t id)
-{
-    Variable addr {0};
-    if(DB_DATA.has(id)) {
-        DB_DATA.get(id, addr);
     }
     return addr;
+ }
+
+void drop(Variable addr)
+{
+    if(addr.address != nullptr) {
+        switch(addr.type) {
+            case Type::Tag::Boolean:
+            case Type::Tag::Natural:
+            case Type::Tag::Integer:
+            case Type::Tag::Block:
+                break;
+
+            case Type::Tag::Varying: {
+                Variable& var = *reinterpret_cast<Variable*>(addr.address);
+                if(var.address != nullptr) {
+                    drop(var);
+                }
+                var.type = 0;
+                var.address = nullptr;
+            } break;
+
+            case Type::Tag::List: {
+                //Type::List& list = *reinterpret_cast<Type::List*>(addr.address);
+                //if(list.data != nullptr) {
+                //    for(size_t i = 0; i < list.length; ++i) {
+                //        drop(list_cell(addr, i));
+                //    }
+                //    free(list.data);
+                //}
+            } break;
+        }
+        memset(addr.address, 0, type_size(addr.type));
+    }
+}
+
+extern "C" void release(Variable addr)
+{
+    if(addr.address != nullptr) {
+        drop(addr);
+        free(addr.address);
+    }
 }
 
 bool copy(Variable src, Variable dst)
@@ -114,8 +130,7 @@ bool copy(Variable src, Variable dst)
                 dest_ref.type = Type::Tag::Null;
                 dest_ref.address = nullptr;
             }
-            dest_ref.type = source.type;
-            dest_ref.address = allocate(dest_ref.type, 1);
+            dest_ref = acquire(source.type);
         }
     }
 
@@ -132,7 +147,7 @@ bool copy(Variable src, Variable dst)
                 memcpy(destination.address, source.address, type_size(source.type));
             } break;
             
-            case Type::Tag::List: {
+            /*case Type::Tag::List: {
                 auto& src_list = *reinterpret_cast<Type::List*>(source.address);
                 auto& dst_list = *reinterpret_cast<Type::List*>(destination.address);
                 
@@ -143,7 +158,7 @@ bool copy(Variable src, Variable dst)
                 for(size_t i = 0; i < src_list.length; ++i) {
                     copy(list_at(source, i), list_at(destination, i));
                 }
-            } break;
+            } break;*/
         }
 
         return true;
@@ -153,21 +168,68 @@ bool copy(Variable src, Variable dst)
 }
 
 
+// Varying //
+
+extern "C" Variable varying_get(Variable addr)
+{
+    Variable result {0};
+    //if(type_key(addr.type) == Type::Tag::Varying) {
+        result = *reinterpret_cast<Variable*>(addr.address);
+    //}
+    return result;
+}
+
+extern "C" void varying_set(Variable addr, Variable source)
+{
+    //if(type_key(addr.type) == Type::Tag::Varying) {
+        Variable& var = *reinterpret_cast<Variable*>(addr.address);
+        
+        if(var.address != nullptr) {
+            drop(var);
+        }
+    
+        if(var.type != source.type || var.address == nullptr) {
+            if(var.address != nullptr) {
+                free(var.address);
+            }
+            var.type = source.type;
+            var.address = allocate(source.type, 1);
+        }
+
+        copy(source, var);
+    //}
+}
+
+extern "C" void varying_clear(Variable addr)
+{
+    //if(type_key(addr.type) == Type::Tag::Varying) {
+        Variable& var = *reinterpret_cast<Variable*>(addr.address);
+        
+        if(var.address != nullptr) {
+            drop(var);
+            free(var.address);
+            var.type = 0;
+            var.address = nullptr;
+        }
+    //}
+}
+
+
 // Boolean //
 
 extern "C" void bool_set(Variable addr, Type::Boolean value)
 {
-    if(type_key(addr.type) == Type::Tag::Boolean) {
+    //if(type_key(addr.type) == Type::Tag::Boolean) {
         *(reinterpret_cast<Type::Boolean*>(addr.address)) = value;
-    }
+    //}
 }
 
 extern "C" Type::Boolean bool_get(Variable addr)
 {
-    if(type_key(addr.type) == Type::Tag::Boolean) {
+    //if(type_key(addr.type) == Type::Tag::Boolean) {
         return *(reinterpret_cast<Type::Boolean*>(addr.address));
-    }
-    return false;
+    //}
+    //return false;
 }
 
 
@@ -175,17 +237,17 @@ extern "C" Type::Boolean bool_get(Variable addr)
 
 extern "C" void natural_set(Variable addr, Type::Natural value)
 {
-    if(type_key(addr.type) == Type::Tag::Natural) {
+    //if(type_key(addr.type) == Type::Tag::Natural) {
         *(reinterpret_cast<Type::Natural*>(addr.address)) = value;
-    }
+    //}
 }
 
 extern "C" Type::Natural natural_get(Variable addr)
 {
-    if(type_key(addr.type) == Type::Tag::Natural) {
+    //if(type_key(addr.type) == Type::Tag::Natural) {
         return *(reinterpret_cast<Type::Natural*>(addr.address));
-    }
-    return false;
+    //}
+    //return false;
 }
 
 
@@ -193,192 +255,293 @@ extern "C" Type::Natural natural_get(Variable addr)
 
 extern "C" void integer_set(Variable addr, Type::Integer value)
 {
-    if(type_key(addr.type) == Type::Tag::Integer) {
+    //if(type_key(addr.type) == Type::Tag::Integer) {
         *(reinterpret_cast<Type::Integer*>(addr.address)) = value;
-    }
+    //}
 }
 
 extern "C" Type::Integer integer_get(Variable addr)
 {
-    if(type_key(addr.type) == Type::Tag::Integer) {
+    //if(type_key(addr.type) == Type::Tag::Integer) {
         return *(reinterpret_cast<Type::Integer*>(addr.address));
-    }
-    return false;
+    //}
+    //return false;
 }
 
 
-// List
+// Block //
+
+extern "C" uint8_t block_get(Variable addr, size_t index)
+{
+    //if(type_key(addr.type) == Type::Tag::Block) {
+        size_t length = type_key(type_inner(addr.type));
+        if(index < length) {
+            return reinterpret_cast<uint8_t*>(addr.address)[index];
+        }
+    //}
+    return 0;
+}
+
+extern "C" void block_set(Variable addr, size_t index, uint8_t value)
+{
+    //if(type_key(addr.type) == Type::Tag::Block) {
+        size_t length = type_key(type_inner(addr.type));
+        if(index < length) {
+            reinterpret_cast<uint8_t*>(addr.address)[index] = value;
+        }
+    //}
+}
+
+
+// String //
+
+
+// Array //
+
+extern "C" size_t array_length(Variable addr)
+{
+    //if(type_key(addr.type) == Type::Tag::Array) {
+        return type_key(type_inner(addr.type));
+    //}
+    //return 0;
+}
+
+Variable array_cell(Variable addr, size_t index)
+{
+    Variable result {0};
+    //if(type_key(addr.type) == Type::Tag::Array) {
+        size_t length_n = type_inner(addr.type);
+        size_t length = type_key(length_n);
+        size_t type = type_inner(length_n);
+        size_t offset = type_size(type);
+
+        // validate for overflow
+        if(addr.address != nullptr && offset > 0 && index < length) {
+            result.type = type;
+            result.address = reinterpret_cast<void*>(reinterpret_cast<size_t>(addr.address) + (offset * index));
+        }
+    //}
+    return result;
+}
+
+extern "C" Variable array_get(Variable addr, size_t index)
+{
+    Variable result {0};
+    //if(type_key(addr.type) == Type::Tag::Array) {
+        Variable cell = array_cell(addr, index);
+        if(cell.address != nullptr) {
+            if(cell.type == Type::Tag::Varying) {
+                result = varying_get(cell);
+            }
+            else {
+                result = cell;
+            }
+        }
+    //}
+    return result;
+}
+
+extern "C" void array_set(Variable addr, size_t index, Variable source)
+{
+    //if(type_key(addr.type) == Type::Tag::Array) {
+        Variable cell = array_cell(addr, index);
+        if(cell.type == Type::Tag::Varying) {
+            varying_set(cell, source);
+        }
+        else {
+            copy(source, cell);
+        }
+    //}
+}
+
+
+// List //
 
 extern "C" size_t list_capacity(Variable addr)
 {
-    if(type_key(addr.type) == Type::Tag::List) {
+    //if(type_key(addr.type) == Type::Tag::List) {
         return (*reinterpret_cast<Type::List*>(addr.address)).capacity;
-    }
-    return 0;
+    //}
+    //return 0;
 }
 
 extern "C" size_t list_length(Variable addr)
 {
-    if(type_key(addr.type) == Type::Tag::List) {
+    //if(type_key(addr.type) == Type::Tag::List) {
         return (*reinterpret_cast<Type::List*>(addr.address)).length;
-    }
-    return 0;
+    //}
+    //return 0;
 }
 
-extern "C" Variable list_first(Variable addr)
+Variable list_cell(Variable addr, size_t index)
 {
     Variable result {0};
-    if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
-        if(list.length > 0) {
-
-        }
-    }
-    return result;
-}
-
-extern "C" Variable list_last(Variable addr)
-{
-    Variable result {0};
-    if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
-        if(list.length > 0) {
-
-        }
-    }
-    return result;
-}
-
-void* list_cell(Variable addr, size_t index)
-{
-    if(type_key(addr.type) == Type::Tag::List) {
-        uint32_t inner = type_inner(addr.type);
+    //if(type_key(addr.type) == Type::Tag::List) {
         Type::List& list = *reinterpret_cast<Type::List*>(addr.address);
+        size_t inner = type_inner(addr.type);
+        size_t offset = type_size(inner);
 
         // validate for overflow
-        size_t offset = type_size(inner);
         if(list.data != nullptr && offset > 0 && index < list.length) {
-            return reinterpret_cast<void*>(reinterpret_cast<size_t>(addr.address) + (offset * index));
+            result.type = inner;
+            result.address = reinterpret_cast<void*>(reinterpret_cast<size_t>(list.data) + (offset * index));
         }
-    }
-    return nullptr;
+    //}
+    return result;
 }
 
 extern "C" Variable list_at(Variable addr, size_t index)
 {
     Variable result {0};
-    if(type_key(addr.type) == Type::Tag::List) {
-        uint32_t inner = type_inner(addr.type);
-        Type::List& list = *reinterpret_cast<Type::List*>(addr.address);
-
-        void* cell = list_cell(addr, index);
-        if(cell != nullptr) {
-            // handle varying inner type
-            if(type_key(inner) == Type::Tag::Varying) {
-                result = *reinterpret_cast<Variable*>(cell);
+    //if(type_key(addr.type) == Type::Tag::List) {
+        Variable cell = list_cell(addr, index);
+        if(cell.address != nullptr) {
+            if(cell.type == Type::Tag::Varying) {
+                result = *reinterpret_cast<Variable*>(cell.address);
             } else {
-                result.type = inner;
-                result.address = cell;
+                result = cell;
             }
         }
-    }
+    //}
     return result;
 }
 
-extern "C" void list_clear(Variable addr)
+/*extern "C" Variable list_first(Variable addr)
 {
+    Variable result {0};
     if(type_key(addr.type) == Type::Tag::List) {
         auto& list = (*reinterpret_cast<Type::List*>(addr.address));
-        list.length = 0;
-        memset(list.data, 0, list.offset * list.capacity);
+        if(list.length > 0) {
+            result = list_at(addr, 0);
+        }
     }
+    return result;
+}*/
+
+/*extern "C" Variable list_last(Variable addr)
+{
+    Variable result {0};
+    if(type_key(addr.type) == Type::Tag::List) {
+        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+        if(list.length > 0) {
+            result = list_at(addr, list.length - 1);
+        }
+    }
+    return result;
+}*/
+
+extern "C" void list_clear(Variable addr)
+{
+    //if(type_key(addr.type) == Type::Tag::List) {
+        size_t offset = type_size(type_inner(addr.type));
+        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+        for(size_t i = 0; i < list.length; ++i) {
+            drop(list_cell(addr, i));
+        }
+        list.length = 0;
+        memset(list.data, 0, offset * list.capacity);
+    //}
 }
 
-extern "C" void list_prepend(Variable addr, Variable source)
+/*extern "C" void list_prepend(Variable addr, Variable source)
 {
     if(type_key(addr.type) == Type::Tag::List) {
-        uint32_t inner = type_inner(addr.type);
+        size_t inner = type_inner(addr.type);
+        //size_t offset = type_size(inner);
 
         // validate list can store value
         if(type_key(inner) == Type::Tag::Varying || source.type == inner) {
             auto& list = (*reinterpret_cast<Type::List*>(addr.address));
 
             if(list.length == list.capacity) {
-                size_t new_capacity = (list.capacity < 16)? 16 : list.capacity * 2;
-                void* new_data = malloc(list.offset * new_capacity);
-                memset(new_data, 0, list.offset * new_capacity);
-                memcpy(new_data, list.data, list.offset * list.capacity);
+                list_reserve(addr, list.capacity * 2);
             }
 
             // copy source to cell
-            Variable dst {0};
-            dst.type = inner;
-            dst.address = reinterpret_cast<void*>(reinterpret_cast<size_t>(addr.address) + (list.offset * list.length));
-            copy(source, dst);
 
             list.length++;
         }
     }
-}
+}*/
 
-extern "C" void list_append(Variable addr, Variable source)
+/*extern "C" void list_append(Variable addr, Variable source)
 {
     if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
-        
+        Type::List& list = *reinterpret_cast<Type::List*>(addr.address);
+        size_t inner = type_inner(addr.type);
+        //size_t offset = type_size(inner);
+
+        // validate list can store value
+        if(type_key(inner) == Type::Tag::Varying || source.type == inner) {
+            if(list.length == list.capacity) {
+                list_reserve(addr, list.capacity * 2);
+            }
+
+            // copy source to cell
+
+            list.length++;
+        }
     }
-}
+}*/
 
 extern "C" void list_insert(Variable addr, size_t index, Variable source)
 {
-    if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+    //if(type_key(addr.type) == Type::Tag::List) {
+        //auto& list = (*reinterpret_cast<Type::List*>(addr.address));
         
-    }
+    //}
 }
 
-extern "C" void list_truncate(Variable addr, size_t maximum)
+extern "C" void list_update(Variable addr, size_t index, Variable source)
 {
-    if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+    //if(type_key(addr.type) == Type::Tag::List) {
+        //auto& list = (*reinterpret_cast<Type::List*>(addr.address));
         
-    }
+    //}
 }
 
-extern "C" void list_shift(Variable addr)
+/*extern "C" void list_truncate(Variable addr, size_t maximum)
 {
     if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+        //auto& list = (*reinterpret_cast<Type::List*>(addr.address));
         
     }
-}
+}*/
+
+/*extern "C" void list_shift(Variable addr)
+{
+    if(type_key(addr.type) == Type::Tag::List) {
+        //auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+        
+    }
+}*/
 
 extern "C" void list_remove(Variable addr, size_t index, size_t maximum)
 {
-    if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+    //if(type_key(addr.type) == Type::Tag::List) {
+        //auto& list = (*reinterpret_cast<Type::List*>(addr.address));
         
-    }
+    //}
 }
 
 extern "C" void list_reserve(Variable addr, size_t capacity)
 {
-    if(type_key(addr.type) == Type::Tag::List) {
+    //if(type_key(addr.type) == Type::Tag::List) {
         auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+        size_t inner = type_inner(addr.type);
+        size_t offset = type_size(inner);
 
         if(list.capacity < capacity) {
-            void* new_data = allocate(type_inner(addr.type), capacity); //malloc(list.offset * capacity);
-            //memset(new_data, 0, list.offset * capacity);
-            memcpy(new_data, list.data, list.offset * list.capacity);
+            void* new_data = allocate(inner, capacity);
+            memcpy(new_data, list.data, offset * list.capacity);
         }
-    }
+    //}
 }
 
-extern "C" void list_resize(Variable addr, size_t length)
+/*extern "C" void list_resize(Variable addr, size_t length)
 {
     if(type_key(addr.type) == Type::Tag::List) {
-        auto& list = (*reinterpret_cast<Type::List*>(addr.address));
+        //auto& list = (*reinterpret_cast<Type::List*>(addr.address));
         
     }
-}
-
+}*/
diff --git a/src/runtime/lib.h b/src/runtime/lib.h
index a405c99..0910860 100644
--- a/src/runtime/lib.h
+++ b/src/runtime/lib.h
@@ -12,22 +12,26 @@ extern TypeTree DB_TYPE;
 extern NameTree DB_NAME;
 extern Pool<Variable> DB_DATA;
 
-extern "C" uint32_t type_outer(uint32_t id, uint32_t key);
-extern "C" uint32_t type_inner(uint32_t id);
-extern "C" uint32_t type_key(uint32_t id);
-extern "C" size_t type_size(uint32_t type_id);
+extern "C" size_t type_outer(size_t id, size_t key);
+extern "C" size_t type_inner(size_t id);
+extern "C" size_t type_key(size_t id);
+extern "C" size_t type_size(size_t type_id);
 
-void* allocate(uint32_t type_id, size_t count);
-extern "C" size_t acquire(uint32_t type_id);
-extern "C" bool release(size_t id);
-extern "C" Variable address(size_t id);
+void* allocate(size_t type_id, size_t count);
+extern "C" Variable acquire(size_t type_id);
+extern "C" void release(Variable id);
 extern "C" bool copy(Variable src, Variable dst);
 
+// Varying //
+extern "C" Variable varying_get(Variable addr);
+extern "C" void varying_set(Variable addr, Variable source);
+extern "C" void varying_clear(Variable addr);
+
 // Boolean //
 extern "C" void bool_set(Variable addr, Type::Boolean value);
 extern "C" Type::Boolean bool_get(Variable addr);
 
-// Natural //
+// Natural //p
 extern "C" void natural_set(Variable addr, Type::Natural value);
 extern "C" Type::Natural natural_get(Variable addr);
 
@@ -35,19 +39,46 @@ extern "C" Type::Natural natural_get(Variable addr);
 extern "C" void integer_set(Variable addr, Type::Integer value);
 extern "C" Type::Integer integer_get(Variable addr);
 
+// Block //
+extern "C" uint8_t block_get(Variable addr, size_t index);
+extern "C" void block_set(Variable addr, size_t index, uint8_t value);
+
+// String //
+//extern "C" size_t string_length(Variable addr);
+//extern "C" Variable string_get(Variable addr, size_t index);
+//extern "C" void string_clear(Variable addr);
+//extern "C" void string_prepend(Variable addr, Variable source);
+//extern "C" void string_append(Variable addr, Variable source);
+//extern "C" void string_insert(Variable addr, size_t index, Variable source);
+//extern "C" void string_set(Variable addr, size_t index, Variable source);
+//extern "C" void string_truncate(Variable addr, size_t maximum);
+//extern "C" void string_remove(Variable addr, size_t index, size_t maximum);
+
+// Array //
+extern "C" size_t array_length(Variable addr);
+Variable array_cell(Variable addr, size_t index);
+extern "C" Variable array_get(Variable addr, size_t index);
+extern "C" void array_set(Variable addr, size_t index, Variable source);
+
 // List //
+
 extern "C" size_t list_capacity(Variable addr);
 extern "C" size_t list_length(Variable addr);
-extern "C" Variable list_first(Variable addr);
-extern "C" Variable list_last(Variable addr);
-void* list_cell(Variable addr, size_t index);
+Variable list_cell(Variable addr, size_t index);
 extern "C" Variable list_at(Variable addr, size_t index);
+//extern "C" Variable list_first(Variable addr);
+//extern "C" Variable list_last(Variable addr);
 extern "C" void list_clear(Variable addr);
-extern "C" void list_prepend(Variable addr, Variable source);
-extern "C" void list_append(Variable addr, Variable source);
+//extern "C" void list_prepend(Variable addr, Variable source);
+//extern "C" void list_append(Variable addr, Variable source);
 extern "C" void list_insert(Variable addr, size_t index, Variable source);
-extern "C" void list_truncate(Variable addr, size_t maximum);
-extern "C" void list_shift(Variable addr);
+extern "C" void list_update(Variable addr, size_t index, Variable source);
+//extern "C" void list_truncate(Variable addr, size_t maximum);
+//extern "C" void list_shift(Variable addr);
 extern "C" void list_remove(Variable addr, size_t index, size_t maximum);
 extern "C" void list_reserve(Variable addr, size_t capacity);
-extern "C" void list_resize(Variable addr, size_t length);
+//extern "C" void list_resize(Variable addr, size_t length);
+
+// Record //
+
+// Schema //
diff --git a/src/runtime/mod.rs b/src/runtime/mod.rs
index c29a395..ea78573 100644
--- a/src/runtime/mod.rs
+++ b/src/runtime/mod.rs
@@ -6,15 +6,14 @@ pub struct Variable {
 }
 
 extern "C" {
-    pub fn acquire(type_id:u32) -> usize;
-    pub fn release(id:usize) -> bool;
-    pub fn address(id:usize) -> Variable;
+    pub fn acquire(type_id:usize) -> Variable;
+    pub fn release(addr:Variable);
 
-    pub fn type_outer(type_id:u32, key:u32) -> u32;
-    pub fn type_inner(type_id:u32) -> u32;
-    pub fn type_key(type_id:u32) -> u32;
+    pub fn type_outer(type_id:usize, key:usize) -> usize;
+    pub fn type_inner(type_id:usize) -> usize;
+    pub fn type_key(type_id:usize) -> usize;
 
-    pub fn type_size(type_id:u32) -> usize;
+    pub fn type_size(type_id:usize) -> usize;
 
     pub fn bool_set(addr:Variable, data:bool);
     pub fn bool_get(addr:Variable) -> bool;
@@ -25,33 +24,37 @@ extern "C" {
     pub fn integer_set(addr:Variable, data:i64);
     pub fn integer_get(addr:Variable) -> i64;
     
-    // fn block_set(id:u64, data:Vec<u8>);
-    // fn block_get(id:u64) -> Vec<u8>
-    // fn block_at(id:u64, index:u64) -> u8;
+    pub fn block_set(addr:Variable, index:usize, data:u8);
+    pub fn block_get(addr:Variable, index:usize) -> u8;
 
-    // fn string_set(id:u64, data:Vec<u8>);
-    // fn string_get(id:u64) -> Vec<u8>;
-    // fn string_at(id:u64, index:u64) -> u32;
+    //pub fn string_set(id:u64, data:Vec<u8>);
+    //pub fn string_get(id:u64) -> Vec<u8>;
+    //pub fn string_at(id:u64, index:u64) -> u32;
     
-    // fn array_at(id:u64, index:u64) -> [u64;2];
+    pub fn array_length(addr:Variable) -> usize;
+    pub fn array_get(addr:Variable, index:usize) -> Variable;
+    pub fn array_set(addr:Variable, index:usize, source:Variable);
 
     pub fn list_capacity(addr:Variable) -> usize;
     pub fn list_length(addr:Variable) -> usize;
-    pub fn list_first(addr:Variable) -> Variable;
-    pub fn list_last(addr:Variable) -> Variable;
+    //pub fn list_first(addr:Variable) -> Variable;
+    //pub fn list_last(addr:Variable) -> Variable;
     pub fn list_at(addr:Variable, index:usize) -> Variable;
     pub fn list_clear(addr:Variable);
-    pub fn list_prepend(addr:Variable, src:Variable);
-    pub fn list_append(addr:Variable, src:Variable);
+    //pub fn list_prepend(addr:Variable, src:Variable);
+    //pub fn list_append(addr:Variable, src:Variable);
     pub fn list_insert(addr:Variable, index:usize, src:Variable);
-    pub fn list_truncate(addr:Variable, maximum:usize);
-    pub fn list_shift(addr:Variable, maximum:usize);
+    pub fn list_update(addr:Variable, index:usize, src:Variable);
+    //pub fn list_truncate(addr:Variable, maximum:usize);
+    //pub fn list_shift(addr:Variable, maximum:usize);
     pub fn list_remove(addr:Variable, index:usize, maximum:usize);
     pub fn list_reserve(addr:Variable, capacity:usize);
-    pub fn list_resize(addr:Variable, length:usize);
-    
+    //pub fn list_resize(addr:Variable, length:usize);
+
     //pub fn list_cut(addr:Variable, index:usize, length:usize) -> Variable;
 
     //pub fn list_find(addr:Variable, target:Variable, start:usize) -> usize;
     //pub fn list_count(addr:Variable, target:Variable, start:usize) -> usize;
 }
+
+
diff --git a/src/runtime/type.h b/src/runtime/type.h
index 5115388..d53270f 100644
--- a/src/runtime/type.h
+++ b/src/runtime/type.h
@@ -1,6 +1,6 @@
 #include <cstdint>
 
-struct Variable {
+extern "C" struct Variable {
     size_t type;
     void*  address;
 };
@@ -33,10 +33,15 @@ typedef uint64_t Natural;
 typedef int64_t  Integer;
 
 struct List {
-    size_t offset;
     size_t capacity;
     size_t length;
-    void* data;
+    void*  data;
+};
+
+struct Schema {
+    size_t capacity;
+    size_t length;
+    void*  data;
 };
 
 }
diff --git a/src/runtime/typetree.h b/src/runtime/typetree.h
index 73fdfe8..bf3d547 100644
--- a/src/runtime/typetree.h
+++ b/src/runtime/typetree.h
@@ -7,11 +7,11 @@
 class TypeTree {
 public:
     struct Node {
-        uint32_t value;
-        size_t   parent;
+        size_t key;
+        size_t parent;
         std::vector<size_t> children;
         
-        Node(uint32_t value, size_t parent);
+        Node(size_t key, size_t parent);
     };
 
     TypeTree();
@@ -19,15 +19,15 @@ public:
 
     bool has(size_t id);
 
-    size_t outer(size_t id, uint32_t type);
-    uint32_t value(size_t id);
+    size_t outer(size_t id, size_t type);
+    size_t key(size_t id);
     size_t inner(size_t id);
 
 private:
     std::vector<Node> m_nodes;
 };
 
-TypeTree::Node::Node(uint32_t value, size_t parent) :value(value), parent(parent) { }
+TypeTree::Node::Node(size_t key, size_t parent) :key(key), parent(parent) { }
 
 TypeTree::TypeTree()
 {
@@ -42,36 +42,35 @@ bool TypeTree::has(size_t id)
     return id < m_nodes.size();
 }
 
-size_t TypeTree::outer(size_t id, uint32_t value)
+size_t TypeTree::outer(size_t id, size_t key)
 {
     size_t find = 0;
+    //for(size_t i = 0; i < m_nodes.size(); ++i) {
+    //    printf(" - [%u] : %u -> %u [%u]\n", i, m_nodes[i].parent, m_nodes[i].key, m_nodes[i].children.size());
+    //}
 
-    if(id < m_nodes.size())
-    {
+    if(key != 0 && id < m_nodes.size()) {
         Node& node = m_nodes[id];
-
         for(size_t child : node.children) {
-            if(m_nodes[child].value == value) {
+            if(m_nodes[child].key == key) {
                 find = child;
                 break;
             }
         }
 
         if(find == 0) {
-            m_nodes.push_back(Node(value, id));
+            m_nodes.push_back(Node(key, id));
             find = m_nodes.size() - 1;
-
-            node.children.push_back(find);
+            m_nodes[id].children.push_back(find);
         }
     }
-
     return find;
 }
 
-uint32_t TypeTree::value(size_t id)
+size_t TypeTree::key(size_t id)
 {
     if(id > 0 && id < m_nodes.size()) {
-        return m_nodes[id].value;
+        return m_nodes[id].key;
     }
     return 0;
 }
diff --git a/src/tag.rs b/src/tag.rs
index 529899d..e77080a 100644
--- a/src/tag.rs
+++ b/src/tag.rs
@@ -1,28 +1,28 @@
-//pub type Class = u32;
+//pub type Class = usize;
 
-pub const VARYING :u32 = 0x00;
-pub const NULL    :u32 = 0x01;
-pub const BOOLEAN :u32 = 0x02;
+pub const VARYING :usize = 0x00;
+pub const NULL    :usize = 0x01;
+pub const BOOLEAN :usize = 0x02;
 //...
-pub const NATURAL :u32 = 0x10;
-pub const INTEGER :u32 = 0x11;
-//pub const DECIMAL :u32 = 0x12;
-//pub const FLOAT   :u32 = 0x13;
-//pub const COMPLEX :u32 = 0x14;
+pub const NATURAL :usize = 0x10;
+pub const INTEGER :usize = 0x11;
+//pub const DECIMAL :usize = 0x12;
+//pub const FLOAT   :usize = 0x13;
+//pub const COMPLEX :usize = 0x14;
 //...
-//pub const RANGE   :u32 = 0x1c;
-//pub const CHAR    :u32 = 0x1d;
-pub const BLOCK   :u32 = 0x1e;
-pub const STRING  :u32 = 0x1f;
-//pub const OPTIONAL  :u32 = 0x20;
-//pub const SET     :u32 = 0x21;
-pub const ARRAY   :u32 = 0x22;
-pub const LIST    :u32 = 0x23;
-pub const SPARSE  :u32 = 0x24;
-//pub const MAP     :u32 = 0x25;
-//pub const TRIE    :u32 = 0x26;
-//pub const TREE    :u32 = 0x27;
-//pub const GRAPH   :u32 = 0x28;
+//pub const RANGE   :usize = 0x1c;
+//pub const CHAR    :usize = 0x1d;
+pub const BLOCK   :usize = 0x1e;
+pub const STRING  :usize = 0x1f;
+//pub const OPTIONAL  :usize = 0x20;
+//pub const SET     :usize = 0x21;
+pub const ARRAY   :usize = 0x22;
+pub const LIST    :usize = 0x23;
+pub const SPARSE  :usize = 0x24;
+//pub const MAP     :usize = 0x25;
+//pub const TRIE    :usize = 0x26;
+//pub const TREE    :usize = 0x27;
+//pub const GRAPH   :usize = 0x28;
 //...
-pub const RECORD  :u32 = 0x7e;
-pub const SCHEMA  :u32 = 0x7f;
+pub const RECORD  :usize = 0x7e;
+pub const SCHEMA  :usize = 0x7f;