diff --git a/bytecode/src/lib.rs b/bytecode/src/lib.rs
index 26132dd7..3f8f20fa 100644
--- a/bytecode/src/lib.rs
+++ b/bytecode/src/lib.rs
@@ -254,7 +254,7 @@ pub fn disasm<'a>(
                         || global_offset > off + len
                         || prev
                             .get(global_offset as usize)
-                            .map_or(true, |&b| instr_from_byte(b).is_err());
+                            .is_none_or(|&b| instr_from_byte(b).is_err());
                     has_oob |= local_has_oob;
                     let label = labels.get(&global_offset).unwrap();
                     if local_has_oob {
diff --git a/lang/README.md b/lang/README.md
index 4b04266b..0d3255a0 100644
--- a/lang/README.md
+++ b/lang/README.md
@@ -214,6 +214,14 @@ odher_pass := fn(t: Ty2): Ty2 {
 }
 ```
 
+#### tuples
+```hb
+main := fn(): uint {
+	tupl := .(1, 1)
+	return tupl[0] - tupl[1]
+}
+```
+
 #### struct_scopes
 ```hb
 $zr := 0
@@ -475,7 +483,7 @@ arbitrary text
 - `@embed(<string>)`: include relative file as an array of bytes
 - `@inline(<func>, ...<args>)`: equivalent to `<func>(...<args>)` but function is guaranteed to inline, compiler will otherwise never inline
 - `@len(<ty>)`: reports a length of the type of indexing purposes or length ot a string constant
-- `@kindof(<ty>)`: gives an u8 integer describing the kind of type as an index to array `[Builtin, Struct, Enum, Union, Ptr, Slice, Opt, Func, Template, Global, Const, Module]`
+- `@kindof(<ty>)`: gives an u8 integer describing the kind of type as an index to array `[Builtin, Struct, Tuple, Enum, Union, Ptr, Slice, Opt, Func, Template, Global, Const, Module]`
 - `@Any()`: generic parameter based on inference, TBD: this will ake arguments in the future that restrict what is accepted
 - `@error(...<expr>)`: emit compiler error, if reachable, and use arguments to construct a message, can display strings and types
 - `@ChildOf(<ty>)`: returns the child type of the `<ty>`, works for pointers and optionals (`@ChildOf(?u8) == u8`)
diff --git a/lang/src/backend/hbvm.rs b/lang/src/backend/hbvm.rs
index 19e40b9c..c3dc80c1 100644
--- a/lang/src/backend/hbvm.rs
+++ b/lang/src/backend/hbvm.rs
@@ -8,7 +8,7 @@ use {
         utils::{EntSlice, EntVec},
     },
     alloc::{boxed::Box, collections::BTreeMap, string::String, vec::Vec},
-    core::{assert_matches::debug_assert_matches, mem, ops::Range, usize},
+    core::{assert_matches::debug_assert_matches, mem, ops::Range},
     hbbytecode::{self as instrs, *},
     reg::Reg,
 };
@@ -314,7 +314,7 @@ impl Backend for HbvmBackend {
             && self
                 .jump_relocs
                 .last()
-                .map_or(true, |&(r, _)| self.offsets[r as usize] as usize != self.code.len())
+                .is_none_or(|&(r, _)| self.offsets[r as usize] as usize != self.code.len())
         {
             self.code.truncate(self.code.len() - 5);
             self.ret_relocs.pop();
@@ -653,6 +653,7 @@ enum PLoc {
     WideReg(Reg, u16),
     Ref(Reg, u32),
 }
+
 impl PLoc {
     fn reg(self) -> u8 {
         match self {
diff --git a/lang/src/backend/hbvm/regalloc.rs b/lang/src/backend/hbvm/regalloc.rs
index ac358c89..6140100b 100644
--- a/lang/src/backend/hbvm/regalloc.rs
+++ b/lang/src/backend/hbvm/regalloc.rs
@@ -804,6 +804,7 @@ impl Nodes {
         }
     }
 
+    #[expect(unused)]
     fn init_loc_of(&self, def: Nid, types: &Types) -> Reg {
         if self[def].kind == Kind::Arg {
             let mut parama = ParamAlloc(0..11);
@@ -821,8 +822,9 @@ impl Nodes {
         255
     }
 
+    #[expect(unused)]
     fn use_reg_of(&self, def: Nid, usage: Nid) -> Reg {
-        if matches!(self[usage].kind, Kind::Return { .. }) {}
+        //if matches!(self[usage].kind, Kind::Return { .. }) {}
 
         255
     }
@@ -852,7 +854,7 @@ impl<'a> Regalloc<'a> {
         Self { nodes: ctx, tys, res }.run_low(special_count);
     }
 
-    fn run_low(&mut self, special_count: usize) {
+    fn run_low(&mut self, #[expect(unused)] special_count: usize) {
         self.res.general_bundles.clear();
         self.res.node_to_reg.clear();
         #[cfg(debug_assertions)]
diff --git a/lang/src/nodes.rs b/lang/src/nodes.rs
index afd5be1b..4fca2e24 100644
--- a/lang/src/nodes.rs
+++ b/lang/src/nodes.rs
@@ -2089,7 +2089,7 @@ pub enum Kind {
     Call {
         unreachable: bool,
         func: ty::Func,
-        args: ty::Tuple,
+        args: ty::List,
     },
     // [ctrl]
     Die,
diff --git a/lang/src/son.rs b/lang/src/son.rs
index e0023816..ab7021e5 100644
--- a/lang/src/son.rs
+++ b/lang/src/son.rs
@@ -15,9 +15,9 @@ use {
         },
         ty::{
             self, Arg, ArrayLen, CompState, ConstData, EnumData, EnumField, FTask, FuncData,
-            GlobalData, Loc, Module, Offset, OffsetIter, OptLayout, Sig, StringRef, StructData,
-            StructField, SymKey, TemplateData, Tuple, TypeBase, TypeIns, Types, UnionData,
-            UnionField,
+            GlobalData, List, Loc, Module, Offset, OffsetIter, OptLayout, Sig, StringRef,
+            StructData, StructField, SymKey, TemplateData, TupleData, TypeBase, TypeIns, Types,
+            UnionData, UnionField,
         },
         utils::{BitSet, EntSlice, Vc},
         Ident,
@@ -657,7 +657,7 @@ impl<'a> Codegen<'a> {
 
         let fuc = self.tys.ins.funcs.push(FuncData {
             file,
-            sig: Sig { args: Tuple::empty(), ret },
+            sig: Sig { args: List::empty(), ret },
             ..Default::default()
         });
 
@@ -1274,10 +1274,37 @@ impl<'a> Codegen<'a> {
 
                         Some(Value::ptr(self.offset(bs.id, offset)).ty(f))
                     }
+                    ty::Kind::Tuple(t) => {
+                        let Kind::CInt { value: idx } = self.ci.nodes[idx.id].kind else {
+                            return self.error(
+                                index.pos(),
+                                "field index needs to be known at compile time",
+                            );
+                        };
+
+                        let Some((f, offset)) = OffsetIter::new(t, self.tys)
+                            .into_iter(self.tys)
+                            .nth(idx as _)
+                            .map(|(&f, off)| (f, off))
+                        else {
+                            return self.error(
+                                index.pos(),
+                                fa!(
+                                    "struct '{}' has only `{}' fields, \
+                                    but index was '{}'",
+                                    self.ty_display(bs.ty),
+                                    self.tys.tuple_fields(t).len(),
+                                    idx
+                                ),
+                            );
+                        };
+
+                        Some(Value::ptr(self.offset(bs.id, offset)).ty(f))
+                    }
                     _ => self.error(
                         base.pos(),
                         fa!(
-                            "cant index into '{}' which is not array nor slice",
+                            "cant index into '{}' which is not array nor slice or tuple or struct",
                             self.ty_display(bs.ty)
                         ),
                     ),
@@ -1581,14 +1608,51 @@ impl<'a> Codegen<'a> {
                 self.gen_call(func, args, true)
             }
             Expr::Tupl { pos, ty, fields, .. } => {
-                ctx.ty = ty
+                let ty = ty
                     .map(|ty| self.ty(ty))
-                    .or(ctx.ty.map(|ty| self.tys.inner_of(ty).unwrap_or(ty)));
-                inference!(sty, ctx, self, pos, "struct or slice", "<struct_ty>.(...)");
+                    .or(ctx.ty.map(|ty| self.tys.inner_of(ty).unwrap_or(ty)))
+                    .map(ty::Id::expand);
 
-                match sty.expand() {
-                    ty::Kind::Struct(s) => {
-                        let mem = self.new_stack(pos, sty);
+                match ty {
+                    None => {
+                        let arg_base = self.tys.tmp.args.len();
+                        let mut values = Vec::with_capacity(fields.len());
+                        for field in fields {
+                            let val = self.expr(field)?;
+                            self.tys.tmp.args.push(val.ty);
+                            self.ci.nodes.lock(val.id);
+                            values.push(val);
+                        }
+
+                        let Some(fields) = self.tys.pack_args(arg_base) else {
+                            return self.error(pos, "this tuple exceeded the reasonable limit");
+                        };
+
+                        let key = SymKey::Tuple(fields);
+                        let ty::Kind::Tuple(tupl) = self
+                            .tys
+                            .syms
+                            .get_or_insert(key, &mut self.tys.ins, |ins| {
+                                ins.tuples.push(TupleData { fields, ..Default::default() }).into()
+                            })
+                            .expand()
+                        else {
+                            unreachable!()
+                        };
+
+                        let mem = self.new_stack(pos, tupl.into());
+                        let mut offs = OffsetIter::new(tupl, self.tys);
+                        for value in values {
+                            let (ty, offset) = offs.next_ty(self.tys).unwrap();
+                            let mem = self.offset(mem, offset);
+                            self.ci.nodes.unlock(value.id);
+                            self.store_mem(mem, ty, value.id);
+                        }
+
+                        Some(Value::ptr(mem).ty(tupl.into()))
+                    }
+                    Some(ty::Kind::Struct(s)) => {
+                        let mem = self.new_stack(pos, s.into());
                         let mut offs = OffsetIter::new(s, self.tys);
                         for field in fields {
                             let Some((ty, offset)) = offs.next_ty(self.tys) else {
@@ -1617,16 +1681,17 @@ impl<'a> Codegen<'a> {
                                     (append them to the end of the constructor)"),
                             );
                         }
-                        Some(Value::ptr(mem).ty(sty))
+                        Some(Value::ptr(mem).ty(s.into()))
                     }
-                    ty::Kind::Slice(s) => {
+                    Some(ty::Kind::Slice(s)) => {
                         let slice = &self.tys.ins.slices[s];
                         let len = slice.len().unwrap_or(fields.len());
                         let elem = slice.elem;
                         let elem_size = self.tys.size_of(elem);
-                        let aty = slice
-                            .len()
-                            .map_or_else(|| self.tys.make_array(elem, len as ArrayLen), |_| sty);
+                        let aty = slice.len().map_or_else(
+                            || self.tys.make_array(elem, len as ArrayLen),
+                            |_| s.into(),
+                        );
 
                         if len != fields.len() {
                             return self.error(
@@ -1651,13 +1716,13 @@ impl<'a> Codegen<'a> {
 
                         Some(Value::ptr(mem).ty(aty))
                     }
-                    _ => self.error(
+                    Some(t) => self.error(
                         pos,
                         fa!(
                             "the {}type of the constructor is `{}`, \
                                 but thats not a struct nor slice or array",
                             if ty.is_some() { "" } else { "inferred " },
-                            self.ty_display(sty),
+                            self.ty_display(t.compress()),
                         ),
                     ),
                 }
@@ -2393,6 +2458,7 @@ impl<'a> Codegen<'a> {
                 | ty::Kind::Func(_)
                 | ty::Kind::Template(_)
                 | ty::Kind::Global(_)
+                | ty::Kind::Tuple(_)
                 | ty::Kind::Const(_)) => self.error(
                     pos,
                     fa!(
@@ -4146,6 +4212,7 @@ mod tests {
         loops;
         pointers;
         structs;
+        tuples;
         struct_scopes;
         enums;
         unions;
diff --git a/lang/src/ty.rs b/lang/src/ty.rs
index 8262e833..2d4a61ef 100644
--- a/lang/src/ty.rs
+++ b/lang/src/ty.rs
@@ -38,9 +38,9 @@ pub type Offset = u32;
 pub type Size = u32;
 
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default, PartialOrd, Ord)]
-pub struct Tuple(pub u32);
+pub struct List(pub u32);
 
-impl Tuple {
+impl List {
     const LEN_BITS: u32 = 5;
     const LEN_MASK: usize = Self::MAX_LEN - 1;
     const MAX_LEN: usize = 1 << Self::LEN_BITS;
@@ -104,6 +104,12 @@ impl ArgIter {
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Id(NonZeroU32);
 
+impl AsRef<Id> for Id {
+    fn as_ref(&self) -> &Id {
+        self
+    }
+}
+
 impl From<Id> for i64 {
     fn from(value: Id) -> Self {
         value.0.get() as _
@@ -150,6 +156,7 @@ impl crate::ctx_map::CtxEntry for Id {
                 SymKey::Decl(gb.file.into(), gb.name)
             }
             Kind::Slice(s) => SymKey::Array(&ctx.slices[s]),
+            Kind::Tuple(t) => SymKey::Tuple(ctx.tuples[t].fields),
             Kind::Module(_) | Kind::Builtin(_) => {
                 SymKey::Decl(Module::default().into(), Ident::INVALID)
             }
@@ -266,22 +273,19 @@ impl Id {
     }
 
     pub(crate) fn loc(&self, tys: &Types) -> Loc {
+        use Kind as K;
         match self.expand() {
-            Kind::Opt(o)
+            K::Opt(o)
                 if let ty = tys.ins.opts[o].base
                     && ty.loc(tys) == Loc::Reg
                     && (ty.is_pointer() || tys.size_of(ty) < 8) =>
             {
                 Loc::Reg
             }
-            Kind::Ptr(_) | Kind::Enum(_) | Kind::Builtin(_) => Loc::Reg,
-            Kind::Struct(_) | Kind::Union(_) if tys.size_of(*self) == 0 => Loc::Reg,
-            Kind::Struct(_) | Kind::Union(_) | Kind::Slice(_) | Kind::Opt(_) => Loc::Stack,
-            c @ (Kind::Func(_)
-            | Kind::Global(_)
-            | Kind::Module(_)
-            | Kind::Const(_)
-            | Kind::Template(_)) => {
+            K::Ptr(_) | K::Enum(_) | K::Builtin(_) => Loc::Reg,
+            K::Struct(_) | K::Tuple(_) | K::Union(_) if tys.size_of(*self) == 0 => Loc::Reg,
+            K::Struct(_) | K::Tuple(_) | K::Union(_) | K::Slice(_) | K::Opt(_) => Loc::Stack,
+            c @ (K::Func(_) | K::Global(_) | K::Module(_) | K::Const(_) | K::Template(_)) => {
                 unreachable!("{c:?}")
             }
         }
@@ -450,6 +454,7 @@ type_kind! {
     pub enum Kind {
         Builtin,
         Struct,
+        Tuple,
         Enum,
         Union,
         Ptr,
@@ -514,25 +519,25 @@ impl<'a> Display<'a> {
 
 impl core::fmt::Display for Display<'_> {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        use Kind as TK;
-        match TK::from_ty(self.ty) {
-            TK::Module(idx) => {
+        use Kind as K;
+        match K::from_ty(self.ty) {
+            K::Module(idx) => {
                 f.write_str("@use(\"")?;
                 self.files[idx].path.fmt(f)?;
                 f.write_str(")[")?;
                 idx.fmt(f)?;
                 f.write_str("]")
             }
-            TK::Builtin(ty) => f.write_str(to_str(ty)),
-            TK::Opt(ty) => {
+            K::Builtin(ty) => f.write_str(to_str(ty)),
+            K::Opt(ty) => {
                 f.write_str("?")?;
                 self.rety(self.tys.ins.opts[ty].base).fmt(f)
             }
-            TK::Ptr(ty) => {
+            K::Ptr(ty) => {
                 f.write_str("^")?;
                 self.rety(self.tys.ins.ptrs[ty].base).fmt(f)
             }
-            TK::Struct(idx) => {
+            K::Struct(idx) => {
                 let record = &self.tys.ins.structs[idx];
                 if record.name.is_null() {
                     f.write_str("[")?;
@@ -554,7 +559,19 @@ impl core::fmt::Display for Display<'_> {
                     f.write_str(file.ident_str(record.name))
                 }
             }
-            TK::Union(idx) => {
+            K::Tuple(idx) => {
+                f.write_str(".(")?;
+                for (i, &ty) in
+                    self.tys.ins.args[self.tys.ins.tuples[idx].fields.range()].iter().enumerate()
+                {
+                    if i != 0 {
+                        f.write_str(", ")?;
+                    }
+                    self.rety(ty).fmt(f)?;
+                }
+                f.write_str(")")
+            }
+            K::Union(idx) => {
                 let record = &self.tys.ins.unions[idx];
                 if record.name.is_null() {
                     f.write_str("[")?;
@@ -576,27 +593,27 @@ impl core::fmt::Display for Display<'_> {
                     f.write_str(file.ident_str(record.name))
                 }
             }
-            TK::Enum(idx) => {
+            K::Enum(idx) => {
                 let enm = &self.tys.ins.enums[idx];
                 debug_assert!(!enm.name.is_null());
                 let file = &self.files[enm.file];
                 f.write_str(file.ident_str(enm.name))
             }
-            TK::Func(idx) => {
+            K::Func(idx) => {
                 f.write_str("fn")?;
                 idx.fmt(f)
             }
-            TK::Template(idx) => {
+            K::Template(idx) => {
                 f.write_str("fn")?;
                 idx.fmt(f)
             }
-            TK::Global(idx) => {
+            K::Global(idx) => {
                 let global = &self.tys.ins.globals[idx];
                 let file = &self.files[global.file];
                 f.write_str(file.ident_str(global.name))?;
                 f.write_str(" (global)")
             }
-            TK::Slice(idx) => {
+            K::Slice(idx) => {
                 let array = self.tys.ins.slices[idx];
                 f.write_str("[")?;
                 self.rety(array.elem).fmt(f)?;
@@ -606,7 +623,7 @@ impl core::fmt::Display for Display<'_> {
                 }
                 f.write_str("]")
             }
-            TK::Const(idx) => {
+            K::Const(idx) => {
                 let cnst = &self.tys.ins.consts[idx];
                 let file = &self.files[cnst.file];
                 f.write_str(file.ident_str(cnst.name))?;
@@ -618,9 +635,10 @@ impl core::fmt::Display for Display<'_> {
 
 #[derive(PartialEq, Eq, Hash, Clone, Copy)]
 pub enum SymKey<'a> {
+    Tuple(List),
     Pointer(&'a PtrData),
     Optional(&'a OptData),
-    Type(Id, Pos, Tuple),
+    Type(Id, Pos, List),
     Decl(Id, Ident),
     Array(&'a ArrayData),
     Constant(&'a ConstData),
@@ -628,7 +646,7 @@ pub enum SymKey<'a> {
 
 #[derive(Clone, Copy, Default)]
 pub struct Sig {
-    pub args: Tuple,
+    pub args: List,
     pub ret: Id,
 }
 
@@ -722,7 +740,7 @@ pub struct TypeBase {
     pub pos: Pos,
     pub name: Ident,
     pub field_start: u32,
-    pub captured: Tuple,
+    pub captured: List,
     pub ast: ExprRef,
 }
 
@@ -764,6 +782,13 @@ pub struct StructData {
 
 impl_deref!(StructData { base: TypeBase });
 
+#[derive(Default)]
+pub struct TupleData {
+    pub fields: List,
+    pub size: Cell<Size>,
+    pub align: Cell<u8>,
+}
+
 #[derive(PartialEq, Eq, Hash, Clone, Copy)]
 pub struct OptData {
     pub base: Id,
@@ -854,6 +879,7 @@ pub struct TypeIns {
     pub ptrs: EntVec<Ptr, PtrData>,
     pub opts: EntVec<Opt, OptData>,
     pub slices: EntVec<Slice, ArrayData>,
+    pub tuples: EntVec<Tuple, TupleData>,
 }
 
 pub struct FTask {
@@ -897,6 +923,7 @@ impl Types {
             | Kind::Builtin(_)
             | Kind::Ptr(_)
             | Kind::Slice(_)
+            | Kind::Tuple(_)
             | Kind::Opt(_) => utils::is_pascal_case,
             Kind::Func(f)
                 if let &Expr::Closure { ret: &Expr::Ident { id, .. }, .. } =
@@ -919,19 +946,19 @@ impl Types {
         }
     }
 
-    pub fn pack_args(&mut self, arg_base: usize) -> Option<Tuple> {
+    pub fn pack_args(&mut self, arg_base: usize) -> Option<List> {
         let base = self.ins.args.len();
         self.ins.args.extend(self.tmp.args.drain(arg_base..));
         let needle = &self.ins.args[base..];
         if needle.is_empty() {
-            return Some(Tuple::empty());
+            return Some(List::empty());
         }
         let len = needle.len();
         // FIXME: maybe later when this becomes a bottleneck we use more
         // efficient search (SIMD?, indexing?)
         let sp = self.ins.args.windows(needle.len()).position(|val| val == needle).unwrap();
         self.ins.args.truncate((sp + needle.len()).max(base));
-        Tuple::new(sp, len)
+        List::new(sp, len)
     }
 
     pub fn union_fields(&self, union: Union) -> &[UnionField] {
@@ -1014,6 +1041,16 @@ impl Types {
                 self.ins.structs[stru].size.set(oiter.offset);
                 oiter.offset
             }
+            Kind::Tuple(tuple) => {
+                if self.ins.tuples[tuple].size.get() != 0 {
+                    return self.ins.tuples[tuple].size.get();
+                }
+
+                let mut oiter = OffsetIter::new(tuple, self);
+                while oiter.next(self).is_some() {}
+                self.ins.tuples[tuple].size.set(oiter.offset);
+                oiter.offset
+            }
             Kind::Union(union) => {
                 if self.ins.unions[union].size.get() != 0 {
                     return self.ins.unions[union].size.get();
@@ -1033,8 +1070,12 @@ impl Types {
                     self.size_of(base) + self.align_of(base)
                 }
             }
-            _ if let Some(size) = ty.simple_size() => size,
-            ty => unimplemented!("size_of: {:?}", ty),
+            Kind::Ptr(_) | Kind::Builtin(_) => ty.simple_size().unwrap(),
+            Kind::Func(_)
+            | Kind::Template(_)
+            | Kind::Global(_)
+            | Kind::Const(_)
+            | Kind::Module(_) => unreachable!(),
         }
     }
 
@@ -1066,6 +1107,15 @@ impl Types {
                 self.ins.structs[stru].align.set(align.try_into().unwrap());
                 align
             }
+            Kind::Tuple(tuple) => {
+                if self.ins.tuples[tuple].align.get() != 0 {
+                    return self.ins.tuples[tuple].align.get() as _;
+                }
+                let align =
+                    self.tuple_fields(tuple).iter().map(|&f| self.align_of(f)).max().unwrap_or(1);
+                self.ins.tuples[tuple].align.set(align.try_into().unwrap());
+                align
+            }
             Kind::Slice(arr) => {
                 let arr = &self.ins.slices[arr];
                 match arr.len {
@@ -1073,7 +1123,14 @@ impl Types {
                     _ => self.align_of(arr.elem),
                 }
             }
-            _ => self.size_of(ty).max(1),
+            Kind::Opt(opt) => self.align_of(self.ins.opts[opt].base),
+            Kind::Builtin(_) | Kind::Enum(_) | Kind::Ptr(_) => self.size_of(ty),
+            Kind::Func(_)
+            | Kind::Template(_)
+            | Kind::Global(_)
+            | Kind::Const(_)
+            | Kind::Module(_) => unreachable!(),
+            //_ => self.size_of(ty).max(1),
         }
     }
 
@@ -1161,6 +1218,7 @@ impl Types {
             | Kind::Template(_)
             | Kind::Global(_)
             | Kind::Module(_)
+            | Kind::Tuple(_)
             | Kind::Const(_) => return None,
         })
     }
@@ -1186,7 +1244,7 @@ impl Types {
         self.type_base_of(ty).map(|b| b.parent)
     }
 
-    pub fn captures_of<'a>(&self, ty: Id, file: &'a parser::Ast) -> Option<(&'a [Ident], Tuple)> {
+    pub fn captures_of<'a>(&self, ty: Id, file: &'a parser::Ast) -> Option<(&'a [Ident], List)> {
         let base = self.type_base_of(ty)?;
 
         let (Expr::Struct { captured, .. }
@@ -1212,6 +1270,10 @@ impl Types {
         let str = unsafe { core::mem::transmute::<&mut Vec<u8>, &mut String>(data) };
         write!(str, "{}", Display::new(self, files, ty)).unwrap();
     }
+
+    pub fn tuple_fields(&self, tuple: Tuple) -> &[Id] {
+        &self.ins.args[self.ins.tuples[tuple].fields.range()]
+    }
 }
 
 pub struct OptLayout {
@@ -1220,17 +1282,57 @@ pub struct OptLayout {
     pub payload_offset: Offset,
 }
 
-pub struct OffsetIter {
-    strct: Struct,
+pub trait Agregate: Copy {
+    type Field: AsRef<Id> + 'static;
+
+    fn fields(self, tys: &Types) -> Range<usize>;
+    fn field_by_idx(tys: &Types, index: usize) -> &Self::Field;
+    fn align_override(self, _: &Types) -> Option<u8> {
+        None
+    }
+}
+
+impl Agregate for Tuple {
+    type Field = Id;
+
+    fn fields(self, tys: &Types) -> Range<usize> {
+        tys.ins.tuples[self].fields.range()
+    }
+
+    fn field_by_idx(tys: &Types, index: usize) -> &Self::Field {
+        &tys.ins.args[index]
+    }
+}
+
+impl Agregate for Struct {
+    type Field = StructField;
+
+    fn fields(self, tys: &Types) -> Range<usize> {
+        tys.struct_field_range(self)
+    }
+
+    fn field_by_idx(tys: &Types, index: usize) -> &Self::Field {
+        &tys.ins.struct_fields[index]
+    }
+
+    fn align_override(self, tys: &Types) -> Option<u8> {
+        tys.ins.structs[self].explicit_alignment
+    }
+}
+
+impl AsRef<Id> for StructField {
+    fn as_ref(&self) -> &Id {
+        &self.ty
+    }
+}
+
+pub struct OffsetIter<T> {
+    strct: T,
     offset: Offset,
     fields: Range<usize>,
 }
 
-impl OffsetIter {
-    pub fn new(strct: Struct, tys: &Types) -> Self {
-        Self { strct, offset: 0, fields: tys.struct_field_range(strct) }
-    }
-
+impl OffsetIter<Struct> {
     pub fn offset_of(tys: &Types, idx: Struct, field: &str) -> Option<(Offset, Id)> {
         let field_id = tys.names.project(field)?;
         OffsetIter::new(idx, tys)
@@ -1238,25 +1340,33 @@ impl OffsetIter {
             .find(|(f, _)| f.name == field_id)
             .map(|(f, off)| (off, f.ty))
     }
+}
 
-    fn next<'a>(&mut self, tys: &'a Types) -> Option<(&'a StructField, Offset)> {
-        let stru = &tys.ins.structs[self.strct];
-        let field = &tys.ins.struct_fields[self.fields.next()?];
+impl<T: Agregate> OffsetIter<T> {
+    pub fn new(strct: T, tys: &Types) -> Self {
+        Self { strct, offset: 0, fields: strct.fields(tys) }
+    }
 
-        let align = stru.explicit_alignment.map_or_else(|| tys.align_of(field.ty), |a| a as u32);
+    fn next<'a>(&mut self, tys: &'a Types) -> Option<(&'a T::Field, Offset)> {
+        let field = &T::field_by_idx(tys, self.fields.next()?);
+
+        let align = self
+            .strct
+            .align_override(tys)
+            .map_or_else(|| tys.align_of(*field.as_ref()), |a| a as u32);
         self.offset = (self.offset + align - 1) & !(align - 1);
 
         let off = self.offset;
-        self.offset += tys.size_of(field.ty);
+        self.offset += tys.size_of(*field.as_ref());
         Some((field, off))
     }
 
     pub fn next_ty(&mut self, tys: &Types) -> Option<(Id, Offset)> {
         let (field, off) = self.next(tys)?;
-        Some((field.ty, off))
+        Some((*field.as_ref(), off))
     }
 
-    pub fn into_iter(mut self, tys: &Types) -> impl Iterator<Item = (&StructField, Offset)> {
+    pub fn into_iter(mut self, tys: &Types) -> impl Iterator<Item = (&T::Field, Offset)> {
         core::iter::from_fn(move || self.next(tys))
     }
 }
diff --git a/lang/tests/son_tests_tuples.txt b/lang/tests/son_tests_tuples.txt
new file mode 100644
index 00000000..5aa16aa1
--- /dev/null
+++ b/lang/tests/son_tests_tuples.txt
@@ -0,0 +1,6 @@
+main:
+    CP r1, r0
+    JALA r0, r31, 0a
+code size: 22
+ret: 0
+status: Ok(())