Add core::reflect, start migrating core::repr to use it. Tidy up various Repr types.

8 files changed, 925 insertions, 47 deletions

diff --git a/src/libcore/at_vec.rs b/src/libcore/at_vec.rs
index 4fbc05821f8..845437ac959 100644
--- a/src/libcore/at_vec.rs
+++ b/src/libcore/at_vec.rs
@@ -30,7 +30,7 @@ pure fn capacity<T>(&&v: @[const T]) -> uint {
     unsafe {
         let repr: **unsafe::VecRepr =
             ::unsafe::reinterpret_cast(&addr_of(v));
-        (**repr).alloc / sys::size_of::<T>()
+        (**repr).unboxed.alloc / sys::size_of::<T>()
     }
 }
 
@@ -155,14 +155,14 @@ mod unsafe {
     #[inline(always)]
     unsafe fn set_len<T>(&&v: @[const T], new_len: uint) {
         let repr: **VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-        (**repr).fill = new_len * sys::size_of::<T>();
+        (**repr).unboxed.fill = new_len * sys::size_of::<T>();
     }
 
     #[inline(always)]
     unsafe fn push<T>(&v: @[const T], +initval: T) {
         let repr: **VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-        let fill = (**repr).fill;
-        if (**repr).alloc > fill {
+        let fill = (**repr).unboxed.fill;
+        if (**repr).unboxed.alloc > fill {
             push_fast(v, move initval);
         }
         else {
@@ -173,9 +173,9 @@ mod unsafe {
     #[inline(always)] // really pretty please
     unsafe fn push_fast<T>(&v: @[const T], +initval: T) {
         let repr: **VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-        let fill = (**repr).fill;
-        (**repr).fill += sys::size_of::<T>();
-        let p = ptr::addr_of((**repr).data);
+        let fill = (**repr).unboxed.fill;
+        (**repr).unboxed.fill += sys::size_of::<T>();
+        let p = ptr::addr_of((**repr).unboxed.data);
         let p = ptr::offset(p, fill) as *mut T;
         rusti::move_val_init(*p, move initval);
     }
diff --git a/src/libcore/box.rs b/src/libcore/box.rs
index 8629ffc78e0..bb64080834e 100644
--- a/src/libcore/box.rs
+++ b/src/libcore/box.rs
@@ -5,8 +5,25 @@
 #[forbid(deprecated_pattern)];
 
 use cmp::{Eq, Ord};
+use intrinsic::TyDesc;
 
-export ptr_eq;
+export ptr_eq, raw;
+
+mod raw {
+
+    struct BoxHeaderRepr {
+        ref_count: uint,
+        type_desc: *TyDesc,
+        prev: *BoxRepr,
+        next: *BoxRepr,
+    }
+
+    struct BoxRepr {
+        header: BoxHeaderRepr,
+        data: u8
+    }
+
+}
 
 pure fn ptr_eq<T>(a: @T, b: @T) -> bool {
     //! Determine if two shared boxes point to the same object
diff --git a/src/libcore/cleanup.rs b/src/libcore/cleanup.rs
index 53c5648c96d..6558643507e 100644
--- a/src/libcore/cleanup.rs
+++ b/src/libcore/cleanup.rs
@@ -80,8 +80,8 @@ pub unsafe fn annihilate() {
     let mut box: *mut BoxRepr = transmute(copy box);
     while box != mut_null() {
         debug!("making box immortal: %x", box as uint);
-        (*box).ref_count = 0x77777777;
-        box = transmute(copy (*box).next);
+        (*box).header.ref_count = 0x77777777;
+        box = transmute(copy (*box).header.next);
     }
 
     // Pass 2: Drop all boxes.
@@ -89,11 +89,11 @@ pub unsafe fn annihilate() {
     let mut box: *mut BoxRepr = transmute(copy box);
     while box != mut_null() {
         debug!("calling drop glue for box: %x", box as uint);
-        let tydesc: *TypeDesc = transmute(copy (*box).type_desc);
+        let tydesc: *TypeDesc = transmute(copy (*box).header.type_desc);
         let drop_glue: DropGlue = transmute(((*tydesc).drop_glue, 0));
         drop_glue(to_unsafe_ptr(&tydesc), transmute(&(*box).data));
 
-        box = transmute(copy (*box).next);
+        box = transmute(copy (*box).header.next);
     }
 
     // Pass 3: Free all boxes.
@@ -101,7 +101,7 @@ pub unsafe fn annihilate() {
         let box = (*task).boxed_region.live_allocs;
         if box == null() { break; }
         let mut box: *mut BoxRepr = transmute(copy box);
-        assert (*box).prev == null();
+        assert (*box).header.prev == null();
 
         debug!("freeing box: %x", box as uint);
         rt_free(transmute(box));
diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 1e558a8ded4..48c61e82cb0 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -63,6 +63,7 @@ export unit;
 export uniq;
 export repr;
 export cleanup;
+export reflect;
 
 // NDM seems to be necessary for resolve to work
 export option_iter;
@@ -230,6 +231,7 @@ mod mutable;
 mod flate;
 mod repr;
 mod cleanup;
+mod reflect;
 
 // Modules supporting compiler-generated code
 // Exported but not part of the public interface
diff --git a/src/libcore/reflect.rs b/src/libcore/reflect.rs
new file mode 100644
index 00000000000..c95d1e6ca57
--- /dev/null
+++ b/src/libcore/reflect.rs
@@ -0,0 +1,472 @@
+/*!
+ * Helper types for interfacing with the `intrinsic::visit_ty`
+ * reflection system.
+ */
+
+use intrinsic::{TyDesc, get_tydesc, visit_tydesc, TyVisitor};
+use libc::c_void;
+
+/**
+ * Trait for visitor that wishes to reflect on data. To use this, create a
+ * struct that encapsulates the set of pointers you wish to walk through a
+ * data structure, and implement both `MovePtr` for it as well as `TyVisitor`;
+ * then build a MovePtrAdaptor wrapped around your struct.
+ */
+trait MovePtr {
+    fn move_ptr(adjustment: fn(*c_void) -> *c_void);
+}
+
+/// Helper function for alignment calculation.
+#[inline(always)]
+fn align(size: uint, align: uint) -> uint {
+    ((size + align) - 1u) & !(align - 1u)
+}
+
+/// Adaptor to wrap around visitors implementing MovePtr.
+struct MovePtrAdaptor<V: TyVisitor MovePtr> {
+    inner: V
+}
+pub fn MovePtrAdaptor<V: TyVisitor MovePtr>(+v: V) -> MovePtrAdaptor<V> {
+    MovePtrAdaptor { inner: move v }
+}
+
+/// Abstract type-directed pointer-movement using the MovePtr trait
+impl<V: TyVisitor MovePtr> MovePtrAdaptor<V>: TyVisitor {
+
+    #[inline(always)]
+    fn bump(sz: uint) {
+      do self.inner.move_ptr() |p| {
+            ((p as uint) + sz) as *c_void
+      };
+    }
+
+    #[inline(always)]
+    fn align(a: uint) {
+      do self.inner.move_ptr() |p| {
+            align(p as uint, a) as *c_void
+      };
+    }
+
+    #[inline(always)]
+    fn align_to<T>() {
+        self.align(sys::min_align_of::<T>());
+    }
+
+    #[inline(always)]
+    fn bump_past<T>() {
+        self.bump(sys::size_of::<T>());
+    }
+
+    fn visit_bot() -> bool {
+        self.align_to::<()>();
+        if ! self.inner.visit_bot() { return false; }
+        self.bump_past::<()>();
+        true
+    }
+
+    fn visit_nil() -> bool {
+        self.align_to::<()>();
+        if ! self.inner.visit_nil() { return false; }
+        self.bump_past::<()>();
+        true
+    }
+
+    fn visit_bool() -> bool {
+        self.align_to::<bool>();
+        if ! self.inner.visit_bool() { return false; }
+        self.bump_past::<bool>();
+        true
+    }
+
+    fn visit_int() -> bool {
+        self.align_to::<int>();
+        if ! self.inner.visit_int() { return false; }
+        self.bump_past::<int>();
+        true
+    }
+
+    fn visit_i8() -> bool {
+        self.align_to::<i8>();
+        if ! self.inner.visit_i8() { return false; }
+        self.bump_past::<i8>();
+        true
+    }
+
+    fn visit_i16() -> bool {
+        self.align_to::<i16>();
+        if ! self.inner.visit_i16() { return false; }
+        self.bump_past::<i16>();
+        true
+    }
+
+    fn visit_i32() -> bool {
+        self.align_to::<i32>();
+        if ! self.inner.visit_i32() { return false; }
+        self.bump_past::<i32>();
+        true
+    }
+
+    fn visit_i64() -> bool {
+        self.align_to::<i64>();
+        if ! self.inner.visit_i64() { return false; }
+        self.bump_past::<i64>();
+        true
+    }
+
+    fn visit_uint() -> bool {
+        self.align_to::<uint>();
+        if ! self.inner.visit_uint() { return false; }
+        self.bump_past::<uint>();
+        true
+    }
+
+    fn visit_u8() -> bool {
+        self.align_to::<u8>();
+        if ! self.inner.visit_u8() { return false; }
+        self.bump_past::<u8>();
+        true
+    }
+
+    fn visit_u16() -> bool {
+        self.align_to::<u16>();
+        if ! self.inner.visit_u16() { return false; }
+        self.bump_past::<u16>();
+        true
+    }
+
+    fn visit_u32() -> bool {
+        self.align_to::<u32>();
+        if ! self.inner.visit_u32() { return false; }
+        self.bump_past::<u32>();
+        true
+    }
+
+    fn visit_u64() -> bool {
+        self.align_to::<u64>();
+        if ! self.inner.visit_u64() { return false; }
+        self.bump_past::<u64>();
+        true
+    }
+
+    fn visit_float() -> bool {
+        self.align_to::<float>();
+        if ! self.inner.visit_float() { return false; }
+        self.bump_past::<float>();
+        true
+    }
+
+    fn visit_f32() -> bool {
+        self.align_to::<f32>();
+        if ! self.inner.visit_f32() { return false; }
+        self.bump_past::<f32>();
+        true
+    }
+
+    fn visit_f64() -> bool {
+        self.align_to::<f64>();
+        if ! self.inner.visit_f64() { return false; }
+        self.bump_past::<f64>();
+        true
+    }
+
+    fn visit_char() -> bool {
+        self.align_to::<char>();
+        if ! self.inner.visit_char() { return false; }
+        self.bump_past::<char>();
+        true
+    }
+
+    fn visit_str() -> bool {
+        self.align_to::<~str>();
+        if ! self.inner.visit_str() { return false; }
+        self.bump_past::<~str>();
+        true
+    }
+
+    fn visit_estr_box() -> bool {
+        self.align_to::<@str>();
+        if ! self.inner.visit_estr_box() { return false; }
+        self.bump_past::<@str>();
+        true
+    }
+
+    fn visit_estr_uniq() -> bool {
+        self.align_to::<~str>();
+        if ! self.inner.visit_estr_uniq() { return false; }
+        self.bump_past::<~str>();
+        true
+    }
+
+    fn visit_estr_slice() -> bool {
+        self.align_to::<&static/str>();
+        if ! self.inner.visit_estr_slice() { return false; }
+        self.bump_past::<&static/str>();
+        true
+    }
+
+    fn visit_estr_fixed(n: uint,
+                        sz: uint,
+                        align: uint) -> bool {
+        self.align(align);
+        if ! self.inner.visit_estr_fixed(n, sz, align) { return false; }
+        self.bump(sz);
+        true
+    }
+
+    fn visit_box(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<@u8>();
+        if ! self.inner.visit_box(mtbl, inner) { return false; }
+        self.bump_past::<@u8>();
+        true
+    }
+
+    fn visit_uniq(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<~u8>();
+        if ! self.inner.visit_uniq(mtbl, inner) { return false; }
+        self.bump_past::<~u8>();
+        true
+    }
+
+    fn visit_ptr(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<*u8>();
+        if ! self.inner.visit_ptr(mtbl, inner) { return false; }
+        self.bump_past::<*u8>();
+        true
+    }
+
+    fn visit_rptr(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<&static/u8>();
+        if ! self.inner.visit_rptr(mtbl, inner) { return false; }
+        self.bump_past::<&static/u8>();
+        true
+    }
+
+    fn visit_unboxed_vec(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<vec::raw::UnboxedVecRepr>();
+        if ! self.inner.visit_vec(mtbl, inner) { return false; }
+        true
+    }
+
+    fn visit_vec(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<~[u8]>();
+        if ! self.inner.visit_vec(mtbl, inner) { return false; }
+        self.bump_past::<~[u8]>();
+        true
+    }
+
+    fn visit_evec_box(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<@[u8]>();
+        if ! self.inner.visit_evec_box(mtbl, inner) { return false; }
+        self.bump_past::<@[u8]>();
+        true
+    }
+
+    fn visit_evec_uniq(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<~[u8]>();
+        if ! self.inner.visit_evec_uniq(mtbl, inner) { return false; }
+        self.bump_past::<~[u8]>();
+        true
+    }
+
+    fn visit_evec_slice(mtbl: uint, inner: *TyDesc) -> bool {
+        self.align_to::<&static/[u8]>();
+        if ! self.inner.visit_evec_slice(mtbl, inner) { return false; }
+        self.bump_past::<&static/[u8]>();
+        true
+    }
+
+    fn visit_evec_fixed(n: uint, sz: uint, align: uint,
+                        mtbl: uint, inner: *TyDesc) -> bool {
+        self.align(align);
+        if ! self.inner.visit_evec_fixed(n, sz, align, mtbl, inner) {
+            return false;
+        }
+        self.bump(sz);
+        true
+    }
+
+    fn visit_enter_rec(n_fields: uint, sz: uint, align: uint) -> bool {
+        self.align(align);
+        if ! self.inner.visit_enter_rec(n_fields, sz, align) { return false; }
+        true
+    }
+
+    fn visit_rec_field(i: uint, name: &str,
+                       mtbl: uint, inner: *TyDesc) -> bool {
+        unsafe { self.align((*inner).align); }
+        if ! self.inner.visit_rec_field(i, name, mtbl, inner) {
+            return false;
+        }
+        unsafe { self.bump((*inner).size); }
+        true
+    }
+
+    fn visit_leave_rec(n_fields: uint, sz: uint, align: uint) -> bool {
+        if ! self.inner.visit_leave_rec(n_fields, sz, align) { return false; }
+        true
+    }
+
+    fn visit_enter_class(n_fields: uint, sz: uint, align: uint) -> bool {
+        self.align(align);
+        if ! self.inner.visit_enter_class(n_fields, sz, align) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_class_field(i: uint, name: &str,
+                         mtbl: uint, inner: *TyDesc) -> bool {
+        unsafe { self.align((*inner).align); }
+        if ! self.inner.visit_class_field(i, name, mtbl, inner) {
+            return false;
+        }
+        unsafe { self.bump((*inner).size); }
+        true
+    }
+
+    fn visit_leave_class(n_fields: uint, sz: uint, align: uint) -> bool {
+        if ! self.inner.visit_leave_class(n_fields, sz, align) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_enter_tup(n_fields: uint, sz: uint, align: uint) -> bool {
+        self.align(align);
+        if ! self.inner.visit_enter_tup(n_fields, sz, align) { return false; }
+        true
+    }
+
+    fn visit_tup_field(i: uint, inner: *TyDesc) -> bool {
+        unsafe { self.align((*inner).align); }
+        if ! self.inner.visit_tup_field(i, inner) { return false; }
+        unsafe { self.bump((*inner).size); }
+        true
+    }
+
+    fn visit_leave_tup(n_fields: uint, sz: uint, align: uint) -> bool {
+        if ! self.inner.visit_leave_tup(n_fields, sz, align) { return false; }
+        true
+    }
+
+    fn visit_enter_fn(purity: uint, proto: uint,
+                      n_inputs: uint, retstyle: uint) -> bool {
+        if ! self.inner.visit_enter_fn(purity, proto, n_inputs, retstyle) {
+            return false
+        }
+        true
+    }
+
+    fn visit_fn_input(i: uint, mode: uint, inner: *TyDesc) -> bool {
+        if ! self.inner.visit_fn_input(i, mode, inner) { return false; }
+        true
+    }
+
+    fn visit_fn_output(retstyle: uint, inner: *TyDesc) -> bool {
+        if ! self.inner.visit_fn_output(retstyle, inner) { return false; }
+        true
+    }
+
+    fn visit_leave_fn(purity: uint, proto: uint,
+                      n_inputs: uint, retstyle: uint) -> bool {
+        if ! self.inner.visit_leave_fn(purity, proto, n_inputs, retstyle) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_enter_enum(n_variants: uint, sz: uint, align: uint) -> bool {
+        self.align(align);
+        if ! self.inner.visit_enter_enum(n_variants, sz, align) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_enter_enum_variant(variant: uint,
+                                disr_val: int,
+                                n_fields: uint,
+                                name: &str) -> bool {
+        if ! self.inner.visit_enter_enum_variant(variant, disr_val,
+                                                 n_fields, name) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_enum_variant_field(i: uint, inner: *TyDesc) -> bool {
+        if ! self.inner.visit_enum_variant_field(i, inner) { return false; }
+        true
+    }
+
+    fn visit_leave_enum_variant(variant: uint,
+                                disr_val: int,
+                                n_fields: uint,
+                                name: &str) -> bool {
+        if ! self.inner.visit_leave_enum_variant(variant, disr_val,
+                                                 n_fields, name) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_leave_enum(n_variants: uint, sz: uint, align: uint) -> bool {
+        if ! self.inner.visit_leave_enum(n_variants, sz, align) {
+            return false;
+        }
+        true
+    }
+
+    fn visit_trait() -> bool {
+        self.align_to::<TyVisitor>();
+        if ! self.inner.visit_trait() { return false; }
+        self.bump_past::<TyVisitor>();
+        true
+    }
+
+    fn visit_var() -> bool {
+        if ! self.inner.visit_var() { return false; }
+        true
+    }
+
+    fn visit_var_integral() -> bool {
+        if ! self.inner.visit_var_integral() { return false; }
+        true
+    }
+
+    fn visit_param(i: uint) -> bool {
+        if ! self.inner.visit_param(i) { return false; }
+        true
+    }
+
+    fn visit_self() -> bool {
+        self.align_to::<&static/u8>();
+        if ! self.inner.visit_self() { return false; }
+        self.align_to::<&static/u8>();
+        true
+    }
+
+    fn visit_type() -> bool {
+        if ! self.inner.visit_type() { return false; }
+        true
+    }
+
+    fn visit_opaque_box() -> bool {
+        self.align_to::<@u8>();
+        if ! self.inner.visit_opaque_box() { return false; }
+        self.bump_past::<@u8>();
+        true
+    }
+
+    fn visit_constr(inner: *TyDesc) -> bool {
+        if ! self.inner.visit_constr(inner) { return false; }
+        true
+    }
+
+    fn visit_closure_ptr(ck: uint) -> bool {
+        self.align_to::<fn@()>();
+        if ! self.inner.visit_closure_ptr(ck) { return false; }
+        self.bump_past::<fn@()>();
+        true
+    }
+}
diff --git a/src/libcore/repr.rs b/src/libcore/repr.rs
index f62e4aca68e..a0d6b013407 100644
--- a/src/libcore/repr.rs
+++ b/src/libcore/repr.rs
@@ -4,7 +4,10 @@ use libc::c_void;
 use sys::TypeDesc;
 use to_str::ToStr;
 use unsafe::transmute;
-use intrinsic::{TyDesc, TyVisitor};
+use intrinsic::{TyDesc, TyVisitor, visit_tydesc};
+use reflect::{MovePtr, MovePtrAdaptor};
+use vec::raw::{VecRepr, UnboxedVecRepr, SliceRepr};
+use box::raw::{BoxRepr, BoxHeaderRepr};
 
 /// Helpers
 
@@ -14,21 +17,6 @@ fn align(size: uint, align: uint) -> uint {
     ((size + align) - 1) & !(align - 1)
 }
 
-struct VecRepr {
-    box_header: (uint, uint, uint, uint),
-    mut fill: uint,
-    mut alloc: uint,
-    data: u8
-}
-
-struct BoxRepr {
-    ref_count: uint,
-    type_desc: *TyDesc,
-    prev: *BoxRepr,
-    next: *BoxRepr,
-    data: u8
-}
-
 trait EscapedCharWriter {
     fn write_escaped_char(ch: char);
 }
@@ -118,6 +106,397 @@ impl char : Repr {
     fn write_repr(writer: @Writer) { writer.write_char(self); }
 }
 
+
+// New implementation using reflect::MovePtr
+
+struct ReprVisitor {
+    mut ptr: *c_void,
+    writer: @Writer
+}
+fn ReprVisitor(ptr: *c_void, writer: @Writer) -> ReprVisitor {
+    ReprVisitor { ptr: ptr, writer: writer }
+}
+
+impl ReprVisitor : MovePtr {
+    #[inline(always)]
+    fn move_ptr(adjustment: fn(*c_void) -> *c_void) {
+        self.ptr = adjustment(self.ptr);
+    }
+}
+
+impl ReprVisitor {
+
+    // Various helpers for the TyVisitor impl
+
+    #[inline(always)]
+    fn get<T>(f: fn((&T))) -> bool {
+        unsafe {
+            f(transmute::<*c_void,&T>(copy self.ptr));
+        }
+        true
+    }
+
+    #[inline(always)]
+    fn visit_inner(inner: *TyDesc) -> bool {
+        self.visit_ptr_inner(self.ptr, inner)
+    }
+
+    #[inline(always)]
+    fn visit_ptr_inner(ptr: *c_void, inner: *TyDesc) -> bool {
+        let mut u = ReprVisitor(ptr, self.writer);
+        let v = reflect::MovePtrAdaptor(move u);
+        visit_tydesc(inner, v as @TyVisitor);
+        true
+    }
+
+    #[inline(always)]
+    fn write<T:Repr>() -> bool {
+        do self.get |v:&T| {
+            v.write_repr(self.writer);
+        }
+    }
+
+    fn write_escaped_slice(slice: &str) {
+        self.writer.write_char('"');
+        do str::chars_iter(slice) |ch| {
+            self.writer.write_escaped_char(ch);
+        }
+        self.writer.write_char('"');
+    }
+
+    fn write_mut_qualifier(mtbl: uint) {
+        if mtbl == 0 {
+            self.writer.write_str("mut ");
+        } else if mtbl == 1 {
+            // skip, this is ast::m_imm
+        } else {
+            assert mtbl == 2;
+            self.writer.write_str("const ");
+        }
+    }
+
+    fn write_vec_range(mtbl: uint, ptr: *u8, len: uint,
+                       inner: *TyDesc) -> bool {
+        let mut p = ptr;
+        let end = ptr::offset(p, len);
+        let (sz, al) = unsafe { ((*inner).size, (*inner).align) };
+        self.writer.write_char('[');
+        let mut first = true;
+        while p as uint < end as uint {
+            if first {
+                first = false;
+            } else {
+                self.writer.write_str(", ");
+            }
+            self.write_mut_qualifier(mtbl);
+            self.visit_ptr_inner(p as *c_void, inner);
+            p = align(ptr::offset(p, sz) as uint, al) as *u8;
+        }
+        self.writer.write_char(']');
+        true
+    }
+
+    fn write_unboxed_vec_repr(mtbl: uint, v: &UnboxedVecRepr,
+                              inner: *TyDesc) -> bool {
+        self.write_vec_range(mtbl, ptr::to_unsafe_ptr(&v.data),
+                             v.fill, inner)
+    }
+
+
+}
+
+impl ReprVisitor : TyVisitor {
+    fn visit_bot() -> bool {
+        self.writer.write_str("!");
+        true
+    }
+    fn visit_nil() -> bool { self.write::<()>() }
+    fn visit_bool() -> bool { self.write::<bool>() }
+    fn visit_int() -> bool { self.write::<int>() }
+    fn visit_i8() -> bool { self.write::<i8>() }
+    fn visit_i16() -> bool { self.write::<i16>() }
+    fn visit_i32() -> bool { self.write::<i32>()  }
+    fn visit_i64() -> bool { self.write::<i64>() }
+
+    fn visit_uint() -> bool { self.write::<uint>() }
+    fn visit_u8() -> bool { self.write::<u8>() }
+    fn visit_u16() -> bool { self.write::<u16>() }
+    fn visit_u32() -> bool { self.write::<u32>() }
+    fn visit_u64() -> bool { self.write::<u64>() }
+
+    fn visit_float() -> bool { self.write::<float>() }
+    fn visit_f32() -> bool { self.write::<f32>() }
+    fn visit_f64() -> bool { self.write::<f64>() }
+
+    fn visit_char() -> bool { self.write::<uint>() }
+
+    // Type no longer exists, vestigial function.
+    fn visit_str() -> bool { fail; }
+
+    fn visit_estr_box() -> bool {
+        do self.get::<@str> |s| {
+            self.writer.write_char('@');
+            self.write_escaped_slice(*s);
+        }
+    }
+    fn visit_estr_uniq() -> bool {
+        do self.get::<~str> |s| {
+            self.writer.write_char('~');
+            self.write_escaped_slice(*s);
+        }
+    }
+    fn visit_estr_slice() -> bool {
+        do self.get::<&str> |s| {
+            self.write_escaped_slice(*s);
+        }
+    }
+
+    // Type no longer exists, vestigial function.
+    fn visit_estr_fixed(_n: uint, _sz: uint,
+                        _align: uint) -> bool { fail; }
+
+    fn visit_box(mtbl: uint, inner: *TyDesc) -> bool {
+        self.writer.write_char('@');
+        self.write_mut_qualifier(mtbl);
+        do self.get::<&box::raw::BoxRepr> |b| {
+            let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
+            self.visit_ptr_inner(p, inner);
+        }
+    }
+
+    fn visit_uniq(mtbl: uint, inner: *TyDesc) -> bool {
+        self.writer.write_char('~');
+        self.write_mut_qualifier(mtbl);
+        do self.get::<&box::raw::BoxRepr> |b| {
+            let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
+            self.visit_ptr_inner(p, inner);
+        }
+    }
+
+    fn visit_ptr(_mtbl: uint, _inner: *TyDesc) -> bool {
+        do self.get::<*c_void> |p| {
+            self.writer.write_str(fmt!("(0x%x as *())",
+                                       *p as uint));
+        }
+    }
+
+    fn visit_rptr(mtbl: uint, inner: *TyDesc) -> bool {
+        self.writer.write_char('&');
+        self.write_mut_qualifier(mtbl);
+        do self.get::<*c_void> |p| {
+            self.visit_ptr_inner(*p, inner);
+        }
+    }
+
+    // Type no longer exists, vestigial function.
+    fn visit_vec(_mtbl: uint, _inner: *TyDesc) -> bool { fail; }
+
+
+    fn visit_unboxed_vec(mtbl: uint, inner: *TyDesc) -> bool {
+        do self.get::<vec::raw::UnboxedVecRepr> |b| {
+            self.write_unboxed_vec_repr(mtbl, b, inner);
+        }
+    }
+
+    fn visit_evec_box(mtbl: uint, inner: *TyDesc) -> bool {
+        do self.get::<&VecRepr> |b| {
+            self.writer.write_char('@');
+            self.write_unboxed_vec_repr(mtbl, &b.unboxed, inner);
+        }
+    }
+
+    fn visit_evec_uniq(mtbl: uint, inner: *TyDesc) -> bool {
+        do self.get::<&VecRepr> |b| {
+            self.writer.write_char('~');
+            self.write_unboxed_vec_repr(mtbl, &b.unboxed, inner);
+        }
+    }
+
+    fn visit_evec_slice(mtbl: uint, inner: *TyDesc) -> bool {
+        do self.get::<SliceRepr> |s| {
+            self.writer.write_char('&');
+            self.write_vec_range(mtbl, s.data, s.len, inner);
+        }
+    }
+
+    fn visit_evec_fixed(_n: uint, sz: uint, _align: uint,
+                        mtbl: uint, inner: *TyDesc) -> bool {
+        do self.get::<u8> |b| {
+            self.write_vec_range(mtbl, ptr::to_unsafe_ptr(b), sz, inner);
+        }
+    }
+
+    fn visit_enter_rec(_n_fields: uint,
+                       _sz: uint, _align: uint) -> bool {
+        self.writer.write_char('{');
+        true
+    }
+
+    fn visit_rec_field(i: uint, name: &str,
+                       mtbl: uint, inner: *TyDesc) -> bool {
+        if i != 0 {
+            self.writer.write_str(", ");
+        }
+        self.write_mut_qualifier(mtbl);
+        self.writer.write_str(name);
+        self.writer.write_str(": ");
+        self.visit_inner(inner);
+        true
+    }
+
+    fn visit_leave_rec(_n_fields: uint,
+                       _sz: uint, _align: uint) -> bool {
+        self.writer.write_char('}');
+        true
+    }
+
+    fn visit_enter_class(_n_fields: uint,
+                         _sz: uint, _align: uint) -> bool {
+        self.writer.write_char('{');
+        true
+    }
+    fn visit_class_field(i: uint, name: &str,
+                         mtbl: uint, inner: *TyDesc) -> bool {
+        if i != 0 {
+            self.writer.write_str(", ");
+        }
+        self.write_mut_qualifier(mtbl);
+        self.writer.write_str(name);
+        self.writer.write_str(": ");
+        self.visit_inner(inner);
+        true
+    }
+    fn visit_leave_class(_n_fields: uint,
+                         _sz: uint, _align: uint) -> bool {
+        self.writer.write_char('}');
+        true
+    }
+
+    fn visit_enter_tup(_n_fields: uint,
+                       _sz: uint, _align: uint) -> bool {
+        self.writer.write_char('(');
+        true
+    }
+    fn visit_tup_field(i: uint, inner: *TyDesc) -> bool {
+        if i != 0 {
+            self.writer.write_str(", ");
+        }
+        self.visit_inner(inner);
+        true
+    }
+    fn visit_leave_tup(_n_fields: uint,
+                       _sz: uint, _align: uint) -> bool {
+        self.writer.write_char(')');
+        true
+    }
+
+    fn visit_enter_enum(_n_variants: uint,
+                        _sz: uint, _align: uint) -> bool {
+        true
+    }
+    fn visit_enter_enum_variant(_variant: uint,
+                                _disr_val: int,
+                                _n_fields: uint,
+                                _name: &str) -> bool { true }
+    fn visit_enum_variant_field(_i: uint, inner: *TyDesc) -> bool {
+        self.visit_inner(inner)
+    }
+    fn visit_leave_enum_variant(_variant: uint,
+                                _disr_val: int,
+                                _n_fields: uint,
+                                _name: &str) -> bool { true }
+    fn visit_leave_enum(_n_variants: uint,
+                        _sz: uint, _align: uint) -> bool { true }
+
+    fn visit_enter_fn(_purity: uint, _proto: uint,
+                      _n_inputs: uint, _retstyle: uint) -> bool { true }
+    fn visit_fn_input(_i: uint, _mode: uint, _inner: *TyDesc) -> bool { true }
+    fn visit_fn_output(_retstyle: uint, _inner: *TyDesc) -> bool { true }
+    fn visit_leave_fn(_purity: uint, _proto: uint,
+                      _n_inputs: uint, _retstyle: uint) -> bool { true }
+
+
+    fn visit_trait() -> bool { true }
+    fn visit_var() -> bool { true }
+    fn visit_var_integral() -> bool { true }
+    fn visit_param(_i: uint) -> bool { true }
+    fn visit_self() -> bool { true }
+    fn visit_type() -> bool { true }
+
+    fn visit_opaque_box() -> bool {
+        self.writer.write_char('@');
+        do self.get::<&box::raw::BoxRepr> |b| {
+            let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
+            self.visit_ptr_inner(p, b.header.type_desc);
+        }
+    }
+
+    // Type no longer exists, vestigial function.
+    fn visit_constr(_inner: *TyDesc) -> bool { fail; }
+
+    fn visit_closure_ptr(_ck: uint) -> bool { true }
+}
+
+pub fn write_repr2<T>(writer: @Writer, object: &T) {
+    let ptr = ptr::to_unsafe_ptr(object) as *c_void;
+    let tydesc = intrinsic::get_tydesc::<T>();
+    let mut u = ReprVisitor(ptr, writer);
+    let v = reflect::MovePtrAdaptor(move u);
+    visit_tydesc(tydesc, v as @TyVisitor)
+}
+
+#[test]
+fn test_repr2() {
+    repr::write_repr2(io::stdout(), &10);
+    io::println("");
+    repr::write_repr2(io::stdout(), &true);
+    io::println("");
+    repr::write_repr2(io::stdout(), &false);
+    io::println("");
+    repr::write_repr2(io::stdout(), &1.234);
+    io::println("");
+    repr::write_repr2(io::stdout(), &(&"hello"));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@"hello"));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(~"he\u10f3llo"));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@10));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@mut 10));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(~10));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(~mut 10));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(&10));
+    io::println("");
+    let mut x = 10;
+    repr::write_repr2(io::stdout(), &(&mut x));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(ptr::to_unsafe_ptr(&10) as *int));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@[1,2,3,4,5,6,7,8]));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@[1u8,2u8,3u8,4u8]));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@["hi", "there"]));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(~["hi", "there"]));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(&["hi", "there"]));
+    io::println("");
+    repr::write_repr2(io::stdout(), &({a:10, b:1.234}));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(@{a:10, b:1.234}));
+    io::println("");
+    repr::write_repr2(io::stdout(), &(~{a:10, b:1.234}));
+    io::println("");
+}
+
+
+// Old non-factored implementation, transitional...
+
 enum EnumVisitState {
     PreVariant,     // We're before the variant we're interested in.
     InVariant,      // We're inside the variant we're interested in.
@@ -181,8 +560,8 @@ impl ReprPrinterWrapper {
             self.printer.writer.write_char('"');
             let vec_repr_ptr: **VecRepr = transmute(copy self.printer.ptr);
             let vec_repr = *vec_repr_ptr;
-            let data_ptr = ptr::to_unsafe_ptr(&(*vec_repr).data);
-            let slice: &str = transmute((data_ptr, (*vec_repr).fill));
+            let data_ptr = ptr::to_unsafe_ptr(&(*vec_repr).unboxed.data);
+            let slice: &str = transmute((data_ptr, (*vec_repr).unboxed.fill));
             do str::chars_iter(slice) |ch| {
                 self.printer.writer.write_escaped_char(ch);
             }
@@ -199,7 +578,8 @@ impl ReprPrinterWrapper {
             let box_ptr: **BoxRepr = transmute(copy self.printer.ptr);
             let box = *box_ptr;
             self.printer.ptr = transmute(&(*box).data);
-            intrinsic::visit_tydesc((*box).type_desc, self as @TyVisitor);
+            intrinsic::visit_tydesc((*box).header.type_desc,
+                                    self as @TyVisitor);
             let box_size = sys::size_of::<*BoxRepr>();
             self.printer.ptr = transmute(box_ptr as uint + box_size);
             true
@@ -229,9 +609,9 @@ impl ReprPrinterWrapper {
             let vec_repr_ptr: **VecRepr = transmute(copy self.printer.ptr);
             let old_ptr = self.printer.ptr as uint;
             let vec_repr: *VecRepr = *vec_repr_ptr;
-            self.printer.ptr = transmute(&(*vec_repr).data);
+            self.printer.ptr = transmute(&(*vec_repr).unboxed.data);
             let end_ptr: *c_void = transmute(self.printer.ptr as uint +
-                                             (*vec_repr).fill);
+                                             (*vec_repr).unboxed.fill);
             let sys_tydesc: *TypeDesc = transmute(copy inner);
             let alignment = (*sys_tydesc).align;
             let mut first = true;
diff --git a/src/libcore/str.rs b/src/libcore/str.rs
index 17d6b967029..3d4478080c9 100644
--- a/src/libcore/str.rs
+++ b/src/libcore/str.rs
@@ -2119,8 +2119,9 @@ mod raw {
     /// Sets the length of the string and adds the null terminator
     unsafe fn set_len(&v: ~str, new_len: uint) {
         let repr: *vec::raw::VecRepr = ::unsafe::reinterpret_cast(&v);
-        (*repr).fill = new_len + 1u;
-        let null = ptr::mut_offset(ptr::mut_addr_of((*repr).data), new_len);
+        (*repr).unboxed.fill = new_len + 1u;
+        let null = ptr::mut_offset(ptr::mut_addr_of((*repr).unboxed.data),
+                                   new_len);
         *null = 0u8;
     }
 
diff --git a/src/libcore/vec.rs b/src/libcore/vec.rs
index 22dfa12fae6..2f84a30a49b 100644
--- a/src/libcore/vec.rs
+++ b/src/libcore/vec.rs
@@ -169,7 +169,7 @@ fn reserve_at_least<T>(&v: ~[const T], n: uint) {
 pure fn capacity<T>(&&v: ~[const T]) -> uint {
     unsafe {
         let repr: **raw::VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-        (**repr).alloc / sys::size_of::<T>()
+        (**repr).unboxed.alloc / sys::size_of::<T>()
     }
 }
 
@@ -565,8 +565,8 @@ fn swap_remove<T>(&v: ~[const T], index: uint) -> T {
 fn push<T>(&v: ~[const T], +initval: T) {
     unsafe {
         let repr: **raw::VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-        let fill = (**repr).fill;
-        if (**repr).alloc > fill {
+        let fill = (**repr).unboxed.fill;
+        if (**repr).unboxed.alloc > fill {
             push_fast(v, move initval);
         }
         else {
@@ -579,9 +579,9 @@ fn push<T>(&v: ~[const T], +initval: T) {
 #[inline(always)] // really pretty please
 unsafe fn push_fast<T>(&v: ~[const T], +initval: T) {
     let repr: **raw::VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-    let fill = (**repr).fill;
-    (**repr).fill += sys::size_of::<T>();
-    let p = ptr::addr_of((**repr).data);
+    let fill = (**repr).unboxed.fill;
+    (**repr).unboxed.fill += sys::size_of::<T>();
+    let p = ptr::addr_of((**repr).unboxed.data);
     let p = ptr::offset(p, fill) as *mut T;
     rusti::move_val_init(*p, move initval);
 }
@@ -1787,13 +1787,19 @@ impl<T: Copy> &[T]: ImmutableCopyableVector<T> {
 /// Unsafe operations
 mod raw {
     // FIXME: This should have crate visibility (#1893 blocks that)
-    /// The internal representation of a vector
-    type VecRepr = {
-        box_header: (uint, uint, uint, uint),
+
+    /// The internal representation of a (boxed) vector
+    struct VecRepr {
+        box_header: box::raw::BoxHeaderRepr,
+        unboxed: UnboxedVecRepr
+    }
+
+    /// The internal 'unboxed' representation of a vector
+    struct UnboxedVecRepr {
         mut fill: uint,
         mut alloc: uint,
         data: u8
-    };
+    }
 
     type SliceRepr = {
         mut data: *u8,
@@ -1827,7 +1833,7 @@ mod raw {
     #[inline(always)]
     unsafe fn set_len<T>(&&v: ~[const T], new_len: uint) {
         let repr: **VecRepr = ::unsafe::reinterpret_cast(&addr_of(v));
-        (**repr).fill = new_len * sys::size_of::<T>();
+        (**repr).unboxed.fill = new_len * sys::size_of::<T>();
     }
 
     /**