diff --git a/README.md b/README.md
index 7fb22bb..9f31e6a 100644
--- a/README.md
+++ b/README.md
@@ -19,3 +19,4 @@ todo:
 - iterators?
 - borrow checking
 - basic optimization: use registers, remove temp var moves
+- Cow str
diff --git a/data/test.lang b/data/test.lang
index 4a56d5d..fd635ae 100644
--- a/data/test.lang
+++ b/data/test.lang
@@ -31,7 +31,7 @@ fn start() {
    };
    println("after");
    print(tester());
-   let test = Test {
+   let test: Test = Test {
       a: 10,
       b: 4,
       c: 0,
@@ -59,7 +59,7 @@ fn structer(test: Test) {
    print_dec(test.c);
    println("");
 
-   let test2 = Test2 {
+   let test2: Test2 = Test2 {
       a: 3,
       b: test,
       c: test,
diff --git a/src/compiler/arch/riscv/compile.rs b/src/compiler/arch/riscv/compile.rs
index d14f19c..393207c 100644
--- a/src/compiler/arch/riscv/compile.rs
+++ b/src/compiler/arch/riscv/compile.rs
@@ -4,7 +4,7 @@ use crate::{
     compiler::{arch::riscv::Reg, debug::DebugInfo, UnlinkedFunction, UnlinkedProgram},
     ir::{
         arch::riscv64::{RV64Instruction as AI, RegRef},
-        IRLInstruction as IRI, IRLProgram, Len, Size,
+        LInstruction as IRI, LProgram, Len, Size,
     },
 };
 
@@ -47,7 +47,7 @@ fn mov_mem(
     }
 }
 
-pub fn compile(program: &IRLProgram) -> UnlinkedProgram<LI> {
+pub fn compile(program: &LProgram) -> UnlinkedProgram<LI> {
     let mut fns = Vec::new();
     let mut data = Vec::new();
     let mut dbg = DebugInfo::new(program.labels().to_vec());
diff --git a/src/compiler/mod.rs b/src/compiler/mod.rs
index 1db9c44..db94d01 100644
--- a/src/compiler/mod.rs
+++ b/src/compiler/mod.rs
@@ -7,8 +7,8 @@ mod target;
 use arch::riscv;
 pub use program::*;
 
-use crate::ir::IRLProgram;
+use crate::ir::LProgram;
 
-pub fn compile(program: &IRLProgram) -> UnlinkedProgram<riscv::LinkerInstruction> {
+pub fn compile(program: &LProgram) -> UnlinkedProgram<riscv::LinkerInstruction> {
     arch::riscv::compile(program)
 }
diff --git a/src/ir/id.rs b/src/ir/id.rs
index 0b06019..98fd4da 100644
--- a/src/ir/id.rs
+++ b/src/ir/id.rs
@@ -1,46 +1,51 @@
-use std::fmt::Debug;
-
-#[derive(Clone, Copy, Eq, Hash, PartialEq)]
-pub struct StructID(pub usize);
-#[derive(Clone, Copy, Eq, Hash, PartialEq)]
-pub struct VarID(pub usize);
-#[derive(Clone, Copy, Eq, Hash, PartialEq)]
-pub struct FnID(pub usize);
-#[derive(Clone, Copy, Eq, Hash, PartialEq)]
-pub struct DataID(pub usize);
-#[derive(Clone, Copy, Eq, Hash, PartialEq)]
-pub struct FieldID(pub usize);
+use std::{fmt::Debug, marker::PhantomData};
 
 // I had an idea for why these were different... now I don't
 pub type Size = u32;
 pub type Len = u32;
 
-impl Debug for VarID {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "var{}", self.0)
+pub struct ID<T>(pub usize, PhantomData<T>);
+
+impl<T> ID<T> {
+    pub fn new(i: usize) -> Self {
+        Self(i, PhantomData)
     }
 }
 
-impl Debug for StructID {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "ty{}", self.0)
+pub trait Named {
+    const NAME: &str;
+}
+
+impl<T> From<usize> for ID<T> {
+    fn from(value: usize) -> Self {
+        Self(value, PhantomData)
     }
 }
 
-impl Debug for FnID {
+impl<K: Named> Debug for ID<K> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "fn{}", self.0)
+        write!(f, "{}{}", K::NAME, self.0)
     }
 }
 
-impl Debug for DataID {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "data{}", self.0)
+impl<T> PartialEq for ID<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
     }
 }
 
-impl Debug for FieldID {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "field{}", self.0)
+impl<T> Eq for ID<T> {}
+
+impl<T> std::hash::Hash for ID<T> {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.0.hash(state);
     }
 }
+
+impl<T> Clone for ID<T> {
+    fn clone(&self) -> Self {
+        Self(self.0.clone(), PhantomData)
+    }
+}
+
+impl<T> Copy for ID<T> {}
diff --git a/src/ir/lower/func.rs b/src/ir/lower/func.rs
index 6e86538..ee6431e 100644
--- a/src/ir/lower/func.rs
+++ b/src/ir/lower/func.rs
@@ -5,7 +5,7 @@ use std::collections::HashMap;
 
 #[derive(Debug)]
 pub struct IRLFunction {
-    pub instructions: Vec<IRLInstruction>,
+    pub instructions: Vec<LInstruction>,
     pub stack: HashMap<VarID, Size>,
     pub subvar_map: HashMap<VarID, VarOffset>,
     pub args: Vec<(VarID, Size)>,
@@ -14,7 +14,7 @@ pub struct IRLFunction {
 }
 
 #[derive(Debug)]
-pub enum IRLInstruction {
+pub enum LInstruction {
     Mv {
         dest: VarID,
         dest_offset: Size,
@@ -59,7 +59,7 @@ pub enum IRLInstruction {
     Mark(Symbol),
 }
 
-impl IRLInstruction {
+impl LInstruction {
     pub fn is_ret(&self) -> bool {
         matches!(self, Self::Ret { .. })
     }
diff --git a/src/ir/lower/program.rs b/src/ir/lower/program.rs
index eada48b..e4b5ed4 100644
--- a/src/ir/lower/program.rs
+++ b/src/ir/lower/program.rs
@@ -1,41 +1,38 @@
 use std::collections::HashMap;
 
-use crate::ir::{AsmBlockArgType, IRUFunction, IRUInstrInst, Size, SymbolSpace, VarOffset};
+use crate::ir::{AsmBlockArgType, UInstrInst, Size, SymbolSpace, UFunc, VarOffset};
 
 use super::{
-    IRLFunction, IRLInstruction, IRUInstruction, IRUProgram, Len, Symbol, SymbolSpaceBuilder, Type,
+    IRLFunction, LInstruction, Len, Symbol, SymbolSpaceBuilder, Type, UInstruction, UProgram,
     VarID,
 };
 
-pub struct IRLProgram {
+pub struct LProgram {
     sym_space: SymbolSpace,
     entry: Symbol,
 }
 
 // NOTE: there are THREE places here where I specify size (8)
 
-impl IRLProgram {
-    pub fn create(p: &IRUProgram) -> Result<Self, String> {
-        let mut start = None;
-        for (i, f) in p.iter_fns() {
-            if f.name == "start" {
-                start = Some(i);
-            }
-        }
-        let start = start.ok_or("no start method found")?;
+impl LProgram {
+    pub fn create(p: &UProgram) -> Result<Self, String> {
+        let start = p
+            .names
+            .lookup::<UFunc>("start")
+            .ok_or("no start method found")?;
         let mut ssbuilder = SymbolSpaceBuilder::with_entries(&[start]);
         let entry = ssbuilder.func(&start);
         while let Some((sym, i)) = ssbuilder.pop_fn() {
             let f = p.fns[i.0].as_ref().unwrap();
-            let mut fbuilder = IRLFunctionBuilder::new(p, &mut ssbuilder);
+            let mut fbuilder = LFunctionBuilder::new(p, &mut ssbuilder);
             for i in &f.instructions {
                 fbuilder.insert_instr(i);
             }
             if fbuilder.instrs.last().is_none_or(|i| !i.is_ret()) {
-                fbuilder.instrs.push(IRLInstruction::Ret { src: None });
+                fbuilder.instrs.push(LInstruction::Ret { src: None });
             }
             let res = fbuilder.finish(f);
-            ssbuilder.write_fn(sym, res, Some(f.name.clone()));
+            ssbuilder.write_fn(sym, res, Some(p.names.get(i).to_string()));
         }
         let sym_space = ssbuilder.finish().expect("we failed the mission");
         Ok(Self { sym_space, entry })
@@ -46,10 +43,10 @@ impl IRLProgram {
     }
 }
 
-pub struct IRLFunctionBuilder<'a> {
-    program: &'a IRUProgram,
+pub struct LFunctionBuilder<'a> {
+    program: &'a UProgram,
     builder: &'a mut SymbolSpaceBuilder,
-    instrs: Vec<IRLInstruction>,
+    instrs: Vec<LInstruction>,
     stack: HashMap<VarID, Size>,
     subvar_map: HashMap<VarID, VarOffset>,
     makes_call: bool,
@@ -62,8 +59,8 @@ pub struct LoopCtx {
     bot: Symbol,
 }
 
-impl<'a> IRLFunctionBuilder<'a> {
-    pub fn new(program: &'a IRUProgram, builder: &'a mut SymbolSpaceBuilder) -> Self {
+impl<'a> LFunctionBuilder<'a> {
+    pub fn new(program: &'a UProgram, builder: &'a mut SymbolSpaceBuilder) -> Self {
         Self {
             instrs: Vec::new(),
             stack: HashMap::new(),
@@ -92,50 +89,56 @@ impl<'a> IRLFunctionBuilder<'a> {
             self.subvar_map.insert(i, off);
         }
     }
-    pub fn insert_instr(&mut self, i: &IRUInstrInst) -> Option<Option<String>> {
+    pub fn insert_instr(&mut self, i: &UInstrInst) -> Option<Option<String>> {
         match &i.i {
-            IRUInstruction::Mv { dest, src } => {
+            UInstruction::Mv { dest, src } => {
                 self.alloc_stack(dest.id)?;
                 self.map_subvar(src.id);
-                self.instrs.push(IRLInstruction::Mv {
+                self.instrs.push(LInstruction::Mv {
                     dest: dest.id,
                     dest_offset: 0,
                     src: src.id,
                     src_offset: 0,
                 });
             }
-            IRUInstruction::Ref { dest, src } => {
+            UInstruction::Ref { dest, src } => {
                 self.alloc_stack(dest.id)?;
                 self.map_subvar(src.id);
-                self.instrs.push(IRLInstruction::Ref {
+                self.instrs.push(LInstruction::Ref {
                     dest: dest.id,
                     src: src.id,
                 });
             }
-            IRUInstruction::LoadData { dest, src } => {
+            UInstruction::LoadData { dest, src } => {
                 self.alloc_stack(dest.id)?;
-                let data = &self.program.data[src.0];
-                let ddef = self.program.get_data(*src);
-                let sym = self.builder.ro_data(src, data, Some(ddef.label.clone()));
-                self.instrs.push(IRLInstruction::LoadData {
+                let data = self.program.expect(*src);
+                let sym = self.builder.ro_data(
+                    src,
+                    &data.content,
+                    Some(self.program.names.get(dest.id).to_string()),
+                );
+                self.instrs.push(LInstruction::LoadData {
                     dest: dest.id,
                     offset: 0,
-                    len: data.len() as Len,
+                    len: data.content.len() as Len,
                     src: sym,
                 });
             }
-            IRUInstruction::LoadSlice { dest, src } => {
+            UInstruction::LoadSlice { dest, src } => {
                 self.alloc_stack(dest.id)?;
-                let data = &self.program.data[src.0];
-                let def = self.program.get_data(*src);
-                let Type::Array(_, len) = &def.ty else {
+                let data = self.program.expect(*src);
+                let Type::Array(_, len) = &data.ty else {
                     return Some(Some(format!(
                         "tried to load {} as slice",
-                        self.program.type_name(&def.ty)
+                        self.program.type_name(&data.ty)
                     )));
                 };
-                let sym = self.builder.ro_data(src, data, Some(def.label.clone()));
-                self.instrs.push(IRLInstruction::LoadAddr {
+                let sym = self.builder.ro_data(
+                    src,
+                    &data.content,
+                    Some(self.program.names.get(dest.id).to_string()),
+                );
+                self.instrs.push(LInstruction::LoadAddr {
                     dest: dest.id,
                     offset: 0,
                     src: sym,
@@ -144,23 +147,23 @@ impl<'a> IRLFunctionBuilder<'a> {
                 let sym = self
                     .builder
                     .anon_ro_data(&(*len as u64).to_le_bytes(), Some(format!("len: {}", len)));
-                self.instrs.push(IRLInstruction::LoadData {
+                self.instrs.push(LInstruction::LoadData {
                     dest: dest.id,
                     offset: 8,
                     len: 8,
                     src: sym,
                 });
             }
-            IRUInstruction::LoadFn { dest, src } => {
+            UInstruction::LoadFn { dest, src } => {
                 self.alloc_stack(dest.id)?;
                 let sym = self.builder.func(src);
-                self.instrs.push(IRLInstruction::LoadAddr {
+                self.instrs.push(LInstruction::LoadAddr {
                     dest: dest.id,
                     offset: 0,
                     src: sym,
                 });
             }
-            IRUInstruction::Call { dest, f, args } => {
+            UInstruction::Call { dest, f, args } => {
                 self.alloc_stack(dest.id);
                 self.makes_call = true;
                 let fid = &self.program.fn_map[&f.id];
@@ -171,7 +174,7 @@ impl<'a> IRLFunctionBuilder<'a> {
                 } else {
                     None
                 };
-                let call = IRLInstruction::Call {
+                let call = LInstruction::Call {
                     dest,
                     f: sym,
                     args: args
@@ -184,7 +187,7 @@ impl<'a> IRLFunctionBuilder<'a> {
                 };
                 self.instrs.push(call);
             }
-            IRUInstruction::AsmBlock { instructions, args } => {
+            UInstruction::AsmBlock { instructions, args } => {
                 let mut inputs = Vec::new();
                 let mut outputs = Vec::new();
                 for a in args {
@@ -199,15 +202,15 @@ impl<'a> IRLFunctionBuilder<'a> {
                         }
                     }
                 }
-                self.instrs.push(IRLInstruction::AsmBlock {
+                self.instrs.push(LInstruction::AsmBlock {
                     instructions: instructions.clone(),
                     inputs,
                     outputs,
                 })
             }
-            IRUInstruction::Ret { src } => {
+            UInstruction::Ret { src } => {
                 self.map_subvar(src.id);
-                self.instrs.push(IRLInstruction::Ret {
+                self.instrs.push(LInstruction::Ret {
                     src: if self.program.size_of_var(src.id).expect("unsized var") == 0 {
                         None
                     } else {
@@ -215,9 +218,9 @@ impl<'a> IRLFunctionBuilder<'a> {
                     },
                 })
             }
-            IRUInstruction::Construct { dest, fields } => {
+            UInstruction::Construct { dest, fields } => {
                 self.alloc_stack(dest.id)?;
-                let ty = &self.program.get_var(dest.id).ty;
+                let ty = &self.program.expect(dest.id).ty;
                 let &Type::Struct { id, ref args } = ty else {
                     return Some(Some(format!(
                         "Failed to contruct type {}",
@@ -226,7 +229,7 @@ impl<'a> IRLFunctionBuilder<'a> {
                 };
                 for (&fid, var) in fields {
                     self.map_subvar(var.id);
-                    self.instrs.push(IRLInstruction::Mv {
+                    self.instrs.push(LInstruction::Mv {
                         dest: dest.id,
                         src: var.id,
                         dest_offset: self.program.field_offset(id, fid).expect("field offset"),
@@ -234,19 +237,19 @@ impl<'a> IRLFunctionBuilder<'a> {
                     })
                 }
             }
-            IRUInstruction::If { cond, body } => {
+            UInstruction::If { cond, body } => {
                 self.map_subvar(cond.id);
                 let sym = self.builder.reserve();
-                self.instrs.push(IRLInstruction::Branch {
+                self.instrs.push(LInstruction::Branch {
                     to: *sym,
                     cond: cond.id,
                 });
                 for i in body {
                     self.insert_instr(i);
                 }
-                self.instrs.push(IRLInstruction::Mark(*sym));
+                self.instrs.push(LInstruction::Mark(*sym));
             }
-            IRUInstruction::Loop { body } => {
+            UInstruction::Loop { body } => {
                 let top = self.builder.reserve();
                 let bot = self.builder.reserve();
                 let old = self.loopp;
@@ -254,21 +257,21 @@ impl<'a> IRLFunctionBuilder<'a> {
                     bot: *bot,
                     top: *top,
                 });
-                self.instrs.push(IRLInstruction::Mark(*top));
+                self.instrs.push(LInstruction::Mark(*top));
                 for i in body {
                     self.insert_instr(i);
                 }
-                self.instrs.push(IRLInstruction::Jump(*top));
-                self.instrs.push(IRLInstruction::Mark(*bot));
+                self.instrs.push(LInstruction::Jump(*top));
+                self.instrs.push(LInstruction::Mark(*bot));
                 self.loopp = old;
             }
-            IRUInstruction::Break => {
-                self.instrs.push(IRLInstruction::Jump(
+            UInstruction::Break => {
+                self.instrs.push(LInstruction::Jump(
                     self.loopp.expect("Tried to break outside of loop").bot,
                 ));
             }
-            IRUInstruction::Continue => {
-                self.instrs.push(IRLInstruction::Jump(
+            UInstruction::Continue => {
+                self.instrs.push(LInstruction::Jump(
                     self.loopp.expect("Tried to break outside of loop").top,
                 ));
             }
@@ -276,7 +279,7 @@ impl<'a> IRLFunctionBuilder<'a> {
         Some(None)
     }
 
-    pub fn finish(self, f: &IRUFunction) -> IRLFunction {
+    pub fn finish(self, f: &UFunc) -> IRLFunction {
         IRLFunction {
             instructions: self.instrs,
             makes_call: self.makes_call,
@@ -292,7 +295,7 @@ impl<'a> IRLFunctionBuilder<'a> {
     }
 }
 
-impl std::ops::Deref for IRLProgram {
+impl std::ops::Deref for LProgram {
     type Target = SymbolSpace;
 
     fn deref(&self) -> &Self::Target {
diff --git a/src/ir/upper/def.rs b/src/ir/upper/def.rs
deleted file mode 100644
index c581b72..0000000
--- a/src/ir/upper/def.rs
+++ /dev/null
@@ -1,82 +0,0 @@
-use crate::{
-    common::FileSpan,
-    ir::{FieldID, Len, StructID, VarID},
-};
-
-use super::Type;
-use std::{collections::HashMap, fmt::Debug};
-
-#[derive(Clone)]
-pub struct FnDef {
-    pub name: String,
-    pub args: Vec<VarDef>,
-    pub ret: Type,
-    pub origin: Origin,
-}
-
-#[derive(Clone)]
-pub struct StructField {
-    pub name: String,
-    pub ty: Type,
-}
-
-#[derive(Clone)]
-pub struct StructDef {
-    pub name: String,
-    pub fields: Vec<StructField>,
-    pub field_map: HashMap<String, FieldID>,
-    pub origin: Origin,
-}
-
-#[derive(Clone)]
-pub struct VarDef {
-    pub name: String,
-    pub parent: Option<FieldRef>,
-    pub ty: Type,
-    pub origin: Origin,
-}
-
-#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
-pub struct VarOffset {
-    pub id: VarID,
-    pub offset: Len,
-}
-
-#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
-pub struct FieldRef {
-    pub var: VarID,
-    // this is technically redundant bc you can get it from the var...
-    // but it makes things a lot easier, and you'd have to recheck the fields anyways
-    pub struc: StructID,
-    pub field: FieldID,
-}
-
-#[derive(Clone)]
-pub struct DataDef {
-    pub ty: Type,
-    pub origin: Origin,
-    pub label: String,
-}
-
-pub type Origin = FileSpan;
-
-impl FnDef {
-    pub fn ty(&self) -> Type {
-        Type::Fn {
-            args: self.args.iter().map(|a| a.ty.clone()).collect(),
-            ret: Box::new(self.ret.clone()),
-        }
-    }
-}
-
-impl StructDef {
-    pub fn field(&self, id: FieldID) -> &StructField {
-        &self.fields[id.0]
-    }
-    pub fn get_field(&self, name: &str) -> Option<&StructField> {
-        self.field_map.get(name).map(|id| self.field(*id))
-    }
-    pub fn iter_fields(&self) -> impl Iterator<Item = (FieldID, &StructField)> {
-        self.fields.iter().enumerate().map(|(i, f)| (FieldID(i), f))
-    }
-}
diff --git a/src/ir/upper/error.rs b/src/ir/upper/error.rs
index f2ffe52..0a9ebe1 100644
--- a/src/ir/upper/error.rs
+++ b/src/ir/upper/error.rs
@@ -1,9 +1,9 @@
 use crate::common::{CompilerMsg, CompilerOutput, FileSpan};
 
-use super::{IRUProgram, Type};
+use super::{Type, UProgram};
 
 impl CompilerOutput {
-    pub fn check_assign(&mut self, p: &IRUProgram, src: &Type, dest: &Type, span: FileSpan) {
+    pub fn check_assign(&mut self, p: &UProgram, src: &Type, dest: &Type, span: FileSpan) -> bool {
         // TODO: spans
         if src != dest {
             self.err(CompilerMsg {
@@ -14,6 +14,9 @@ impl CompilerOutput {
                 ),
                 spans: vec![span],
             });
+            true
+        } else {
+            false
         }
     }
 }
diff --git a/src/ir/upper/inst.rs b/src/ir/upper/inst.rs
index 6e93092..e6d9987 100644
--- a/src/ir/upper/inst.rs
+++ b/src/ir/upper/inst.rs
@@ -1,7 +1,7 @@
 use crate::{common::FileSpan, ir::VarID};
 use std::fmt::Debug;
 
-use super::IRUInstruction;
+use super::UInstruction;
 
 #[derive(Clone, Copy)]
 pub struct VarInst {
@@ -9,8 +9,8 @@ pub struct VarInst {
     pub span: FileSpan,
 }
 
-pub struct IRUInstrInst {
-    pub i: IRUInstruction,
+pub struct UInstrInst {
+    pub i: UInstruction,
     pub span: FileSpan,
 }
 
@@ -20,7 +20,7 @@ impl Debug for VarInst {
     }
 }
 
-impl Debug for IRUInstrInst {
+impl Debug for UInstrInst {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{:?}", self.i)
     }
diff --git a/src/ir/upper/func.rs b/src/ir/upper/instr.rs
similarity index 85%
rename from src/ir/upper/func.rs
rename to src/ir/upper/instr.rs
index 58eec34..3e1d0a4 100644
--- a/src/ir/upper/func.rs
+++ b/src/ir/upper/instr.rs
@@ -1,18 +1,9 @@
 use std::{collections::HashMap, fmt::Write};
 
-use super::{
-    arch::riscv64::RV64Instruction, inst::VarInst, DataID, FnID, IRUInstrInst, Type, VarID,
-};
+use super::{arch::riscv64::RV64Instruction, inst::VarInst, DataID, FnID, UInstrInst, UFunc};
 use crate::{compiler::arch::riscv::Reg, ir::FieldID, util::Padder};
 
-pub struct IRUFunction {
-    pub name: String,
-    pub args: Vec<VarID>,
-    pub ret: Type,
-    pub instructions: Vec<IRUInstrInst>,
-}
-
-pub enum IRUInstruction {
+pub enum UInstruction {
     Mv {
         dest: VarInst,
         src: VarInst,
@@ -51,10 +42,10 @@ pub enum IRUInstruction {
     },
     If {
         cond: VarInst,
-        body: Vec<IRUInstrInst>,
+        body: Vec<UInstrInst>,
     },
     Loop {
-        body: Vec<IRUInstrInst>,
+        body: Vec<UInstrInst>,
     },
     Break,
     Continue,
@@ -73,7 +64,7 @@ pub enum AsmBlockArgType {
     Out,
 }
 
-impl std::fmt::Debug for IRUInstruction {
+impl std::fmt::Debug for UInstruction {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             Self::Mv { dest, src } => write!(f, "{dest:?} <- {src:?}")?,
@@ -86,9 +77,7 @@ impl std::fmt::Debug for IRUInstruction {
                 f: func,
                 args,
             } => write!(f, "{dest:?} <- {func:?}({args:?})")?,
-            Self::AsmBlock { args, instructions } => {
-                write!(f, "asm {args:?} {instructions:#?}")?
-            }
+            Self::AsmBlock { args, instructions } => write!(f, "asm {args:?} {instructions:#?}")?,
             Self::Ret { src } => f.debug_struct("Ret").field("src", src).finish()?,
             Self::Construct { dest, fields } => write!(f, "{dest:?} <- {fields:?}")?,
             Self::If { cond, body } => {
@@ -126,9 +115,9 @@ impl std::fmt::Debug for IRUInstruction {
     }
 }
 
-impl std::fmt::Debug for IRUFunction {
+impl std::fmt::Debug for UFunc {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}{:?}", &self.name, self.args)?;
+        write!(f, "{:?}", self.args)?;
         if !self.instructions.is_empty() {
             f.write_str("{\n    ")?;
             let mut padder = Padder::new(f);
diff --git a/src/ir/upper/kind.rs b/src/ir/upper/kind.rs
new file mode 100644
index 0000000..3720519
--- /dev/null
+++ b/src/ir/upper/kind.rs
@@ -0,0 +1,160 @@
+use crate::{
+    common::FileSpan,
+    ir::{Len, Named, ID},
+};
+
+use super::{Type, UInstrInst, UProgram};
+use std::{collections::HashMap, fmt::Debug};
+
+pub const NAMED_KINDS: usize = 4;
+
+pub struct UFunc {
+    pub args: Vec<VarID>,
+    pub ret: Type,
+    pub origin: Origin,
+    pub instructions: Vec<UInstrInst>,
+}
+
+#[derive(Clone)]
+pub struct StructField {
+    pub name: String,
+    pub ty: Type,
+}
+
+#[derive(Clone)]
+pub struct UStruct {
+    pub fields: Vec<StructField>,
+    pub field_map: HashMap<String, FieldID>,
+    pub origin: Origin,
+}
+
+#[derive(Clone)]
+pub struct UVar {
+    pub parent: Option<FieldRef>,
+    pub ty: Type,
+    pub origin: Origin,
+}
+
+#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
+pub struct VarOffset {
+    pub id: VarID,
+    pub offset: Len,
+}
+
+#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
+pub struct FieldRef {
+    pub var: VarID,
+    // this is technically redundant bc you can get it from the var...
+    // but it makes things a lot easier, and you'd have to recheck the fields anyways
+    pub struc: StructID,
+    pub field: FieldID,
+}
+
+#[derive(Clone)]
+pub struct UData {
+    pub ty: Type,
+    pub origin: Origin,
+    pub content: Vec<u8>,
+}
+
+pub type Origin = FileSpan;
+
+impl UFunc {
+    pub fn ty(&self, program: &UProgram) -> Type {
+        Type::Fn {
+            args: self
+                .args
+                .iter()
+                .map(|a| program.expect(*a).ty.clone())
+                .collect(),
+            ret: Box::new(self.ret.clone()),
+        }
+    }
+}
+
+impl UStruct {
+    pub fn field(&self, id: FieldID) -> &StructField {
+        &self.fields[id.0]
+    }
+    pub fn get_field(&self, name: &str) -> Option<&StructField> {
+        self.field_map.get(name).map(|id| self.field(*id))
+    }
+    pub fn iter_fields(&self) -> impl Iterator<Item = (FieldID, &StructField)> {
+        self.fields
+            .iter()
+            .enumerate()
+            .map(|(i, f)| (FieldID::new(i), f))
+    }
+}
+
+pub type StructID = ID<UStruct>;
+pub type VarID = ID<UVar>;
+pub type DataID = ID<UData>;
+pub type FieldID = ID<StructField>;
+pub type FnID = ID<UFunc>;
+
+impl Kind for UFunc {
+    const INDEX: usize = 0;
+    fn from_program_mut(program: &mut UProgram) -> &mut Vec<Option<Self>> {
+        &mut program.fns
+    }
+    fn from_program(program: &UProgram) -> &Vec<Option<Self>> {
+        &program.fns
+    }
+}
+impl Named for UFunc {
+    const NAME: &str = "func";
+}
+
+impl Kind for UVar {
+    const INDEX: usize = 1;
+    fn from_program_mut(program: &mut UProgram) -> &mut Vec<Option<Self>> {
+        &mut program.vars
+    }
+    fn from_program(program: &UProgram) -> &Vec<Option<Self>> {
+        &program.vars
+    }
+}
+impl Named for UVar {
+    const NAME: &str = "var";
+}
+
+impl Kind for UStruct {
+    const INDEX: usize = 2;
+    fn from_program_mut(program: &mut UProgram) -> &mut Vec<Option<Self>> {
+        &mut program.structs
+    }
+    fn from_program(program: &UProgram) -> &Vec<Option<Self>> {
+        &program.structs
+    }
+}
+impl Named for UStruct {
+    const NAME: &str = "struct";
+}
+
+impl Kind for UData {
+    const INDEX: usize = 3;
+    fn from_program_mut(program: &mut UProgram) -> &mut Vec<Option<Self>> {
+        &mut program.data
+    }
+    fn from_program(program: &UProgram) -> &Vec<Option<Self>> {
+        &program.data
+    }
+}
+impl Named for UData {
+    const NAME: &str = "data";
+}
+
+impl Named for StructField {
+    const NAME: &str = "field";
+}
+
+pub trait Kind {
+    const INDEX: usize;
+    fn from_program_mut(program: &mut UProgram) -> &mut Vec<Option<Self>>
+    where
+        Self: Sized;
+    fn from_program(program: &UProgram) -> &Vec<Option<Self>>
+    where
+        Self: Sized;
+}
diff --git a/src/ir/upper/mod.rs b/src/ir/upper/mod.rs
index 56992f9..3ca1b7d 100644
--- a/src/ir/upper/mod.rs
+++ b/src/ir/upper/mod.rs
@@ -1,5 +1,5 @@
-mod def;
-mod func;
+mod kind;
+mod instr;
 mod ty;
 mod program;
 mod validate;
@@ -7,8 +7,8 @@ mod error;
 mod inst;
 
 use super::*;
-pub use def::*;
-pub use func::*;
+pub use kind::*;
+pub use instr::*;
 pub use ty::*;
 pub use program::*;
 pub use inst::*;
diff --git a/src/ir/upper/program.rs b/src/ir/upper/program.rs
index e3ac8f5..5325460 100644
--- a/src/ir/upper/program.rs
+++ b/src/ir/upper/program.rs
@@ -2,40 +2,67 @@ use std::{collections::HashMap, fmt::Debug};
 
 use super::{inst::VarInst, *};
 
-pub struct IRUProgram {
-    pub fn_defs: Vec<FnDef>,
-    pub var_defs: Vec<VarDef>,
-    pub struct_defs: Vec<StructDef>,
-    pub data_defs: Vec<DataDef>,
-    pub fns: Vec<Option<IRUFunction>>,
-    pub data: Vec<Vec<u8>>,
+pub struct UProgram {
+    pub fns: Vec<Option<UFunc>>,
+    pub vars: Vec<Option<UVar>>,
+    pub structs: Vec<Option<UStruct>>,
+    pub data: Vec<Option<UData>>,
+    pub start: Option<FnID>,
+    pub names: NameMap,
+    // todo: these feel weird raw
     pub fn_map: HashMap<VarID, FnID>,
+    pub inv_fn_map: Vec<VarID>,
     pub temp: usize,
-    pub stack: Vec<HashMap<String, Idents>>,
+    pub name_stack: Vec<HashMap<String, Idents>>,
 }
 
-impl IRUProgram {
+pub struct NameMap {
+    names: [Vec<String>; NAMED_KINDS],
+    inv_names: [HashMap<String, usize>; NAMED_KINDS],
+}
+
+impl NameMap {
+    pub fn new() -> Self {
+        Self {
+            names: core::array::from_fn(|_| Vec::new()),
+            inv_names: core::array::from_fn(|_| HashMap::new()),
+        }
+    }
+    pub fn get<K: Kind>(&self, id: ID<K>) -> &str {
+        &self.names[K::INDEX][id.0]
+    }
+    pub fn lookup<K: Kind>(&self, name: &str) -> Option<ID<K>> {
+        Some(ID::new(*self.inv_names[K::INDEX].get(name)?))
+    }
+    pub fn push<K: Kind>(&mut self, name: String) {
+        self.inv_names[K::INDEX].insert(name.clone(), self.names[K::INDEX].len());
+        self.names[K::INDEX].push(name);
+    }
+}
+
+impl UProgram {
     pub fn new() -> Self {
         Self {
-            fn_defs: Vec::new(),
-            var_defs: Vec::new(),
-            struct_defs: Vec::new(),
-            data_defs: Vec::new(),
-            data: Vec::new(),
-            fn_map: HashMap::new(),
             fns: Vec::new(),
+            vars: Vec::new(),
+            structs: Vec::new(),
+            data: Vec::new(),
+            start: None,
+            names: NameMap::new(),
+            fn_map: HashMap::new(),
+            inv_fn_map: Vec::new(),
             temp: 0,
-            stack: vec![HashMap::new()],
+            name_stack: vec![HashMap::new()],
         }
     }
     pub fn push(&mut self) {
-        self.stack.push(HashMap::new());
+        self.name_stack.push(HashMap::new());
     }
     pub fn pop(&mut self) {
-        self.stack.pop();
+        self.name_stack.pop();
     }
-    pub fn get(&self, name: &str) -> Option<Idents> {
-        for map in self.stack.iter().rev() {
+    pub fn get_idents(&self, name: &str) -> Option<Idents> {
+        for map in self.name_stack.iter().rev() {
             let res = map.get(name);
             if res.is_some() {
                 return res.cloned();
@@ -43,43 +70,29 @@ impl IRUProgram {
         }
         None
     }
-    pub fn get_var(&self, id: VarID) -> &VarDef {
-        &self.var_defs[id.0]
+    pub fn get<K: Kind>(&self, id: ID<K>) -> Option<&K> {
+        K::from_program(self)[id.0].as_ref()
     }
-    pub fn get_fn(&self, id: FnID) -> &FnDef {
-        &self.fn_defs[id.0]
+    pub fn get_mut<K: Kind>(&mut self, id: ID<K>) -> Option<&mut K> {
+        K::from_program_mut(self)[id.0].as_mut()
     }
-    pub fn get_data(&self, id: DataID) -> &DataDef {
-        &self.data_defs[id.0]
+    pub fn expect<K: Kind + Named>(&self, id: ID<K>) -> &K {
+        self.get(id)
+            .unwrap_or_else(|| panic!("{id:?} not defined yet!"))
     }
-    pub fn get_fn_var(&self, id: VarID) -> Option<&FnDef> {
-        Some(&self.fn_defs[self.fn_map.get(&id)?.0])
+    pub fn expect_mut<K: Kind + Named>(&mut self, id: ID<K>) -> &mut K {
+        self.get_mut(id)
+            .unwrap_or_else(|| panic!("{id:?} not defined yet!"))
     }
-    pub fn get_struct(&self, id: StructID) -> &StructDef {
-        &self.struct_defs[id.0]
-    }
-    pub fn alias_fn(&mut self, name: &str, id: FnID) {
-        self.insert(name, Ident::Fn(id));
-    }
-    pub fn named_var(&mut self, def: VarDef) -> VarID {
-        // TODO: this is stupid
-        let id = self.def_var(def.clone());
-        self.name_var(&def, id);
-        id
-    }
-    pub fn name_var(&mut self, def: &VarDef, var: VarID) {
-        self.insert(&def.name, Ident::Var(var));
-    }
-    pub fn def_var(&mut self, var: VarDef) -> VarID {
-        let i = self.var_defs.len();
-        self.var_defs.push(var);
-        VarID(i)
+    pub fn get_fn_var(&self, id: VarID) -> Option<&UFunc> {
+        self.fns[self.fn_map.get(&id)?.0].as_ref()
     }
     pub fn size_of_type(&self, ty: &Type) -> Option<Size> {
         // TODO: target matters
         Some(match ty {
             Type::Bits(b) => *b,
-            Type::Struct { id, args } => self.struct_defs[id.0]
+            Type::Struct { id, args } => self.structs[id.0]
+                .as_ref()?
                 .fields
                 .iter()
                 .try_fold(0, |sum, f| Some(sum + self.size_of_type(&f.ty)?))?,
@@ -92,9 +105,8 @@ impl IRUProgram {
             Type::Unit => 0,
         })
     }
-    pub fn struct_layout() {}
     pub fn size_of_var(&self, var: VarID) -> Option<Size> {
-        self.size_of_type(&self.var_defs[var.0].ty)
+        self.size_of_type(&self.get(var)?.ty)
     }
     pub fn temp_subvar(&mut self, origin: Origin, ty: Type, parent: FieldRef) -> VarInst {
         self.temp_var_inner(origin, ty, Some(parent))
@@ -104,12 +116,10 @@ impl IRUProgram {
     }
 
     fn temp_var_inner(&mut self, origin: Origin, ty: Type, parent: Option<FieldRef>) -> VarInst {
-        let v = self.def_var(VarDef {
-            name: format!("temp{}", self.temp),
-            parent,
-            origin,
-            ty,
-        });
+        let v = self.def(
+            format!("temp{}", self.temp),
+            Some(UVar { parent, origin, ty }),
+        );
         self.temp += 1;
         VarInst {
             id: v,
@@ -117,44 +127,29 @@ impl IRUProgram {
         }
     }
 
-    pub fn def_fn(&mut self, def: FnDef) -> FnID {
-        let i = self.fn_defs.len();
-        let id = FnID(i);
-        let var_def = VarDef {
-            name: def.name.clone(),
-            parent: None,
-            origin: def.origin,
-            ty: def.ty(),
-        };
-
-        let vid = self.def_var(var_def);
-        self.insert(&def.name, Ident::Var(vid));
-        self.fn_map.insert(vid, id);
-
-        self.insert(&def.name, Ident::Fn(id));
-        self.fn_defs.push(def);
-        self.fns.push(None);
+    pub fn write<K: Kind>(&mut self, id: ID<K>, k: K) {
+        K::from_program_mut(self)[id.0] = Some(k);
+    }
 
+    pub fn def<K: Kind>(&mut self, name: String, k: Option<K>) -> ID<K> {
+        self.names.push::<K>(name);
+        let vec = K::from_program_mut(self);
+        let id = ID::new(vec.len());
+        vec.push(k);
         id
     }
-    pub fn def_struct(&mut self, def: StructDef) -> StructID {
-        let i = self.struct_defs.len();
-        let id = StructID(i);
-        self.insert(&def.name, Ident::Type(id));
-        self.struct_defs.push(def);
+
+    pub fn def_searchable<K: Kind>(&mut self, name: String, k: Option<K>) -> ID<K> {
+        let id = self.def(name.clone(), k);
+        self.name_on_stack(id, name);
         id
     }
-    pub fn def_data(&mut self, def: DataDef, bytes: Vec<u8>) -> DataID {
-        let i = self.data.len();
-        self.data_defs.push(def);
-        self.data.push(bytes);
-        DataID(i)
-    }
+
     pub fn type_name(&self, ty: &Type) -> String {
         let mut str = String::new();
         match ty {
             Type::Struct { id: base, args } => {
-                str += &self.get_struct(*base).name;
+                str += self.names.get(*base);
                 if let Some(arg) = args.first() {
                     str = str + "<" + &self.type_name(arg);
                 }
@@ -188,81 +183,82 @@ impl IRUProgram {
         }
         str
     }
-    fn insert(&mut self, name: &str, id: Ident) {
-        let idx = self.stack.len() - 1;
-        let last = &mut self.stack[idx];
-        if let Some(l) = last.get_mut(name) {
-            l.insert(id);
+    fn name_on_stack<K: Kind>(&mut self, id: ID<K>, name: String) {
+        let idx = self.name_stack.len() - 1;
+        let last = &mut self.name_stack[idx];
+        if let Some(l) = last.get_mut(&name) {
+            l.insert(id.into());
         } else {
-            last.insert(name.to_string(), Idents::new(id));
+            last.insert(name, Idents::new(id.into()));
         }
     }
-    pub fn write_fn(&mut self, id: FnID, f: IRUFunction) {
-        self.fns[id.0] = Some(f);
-    }
-    pub fn iter_vars(&self) -> impl Iterator<Item = (VarID, &VarDef)> {
-        self.var_defs.iter().enumerate().map(|(i, v)| (VarID(i), v))
-    }
-    pub fn iter_fns(&self) -> impl Iterator<Item = (FnID, &IRUFunction)> {
-        self.fns
-            .iter()
-            .enumerate()
-            .flat_map(|(i, f)| Some((FnID(i), f.as_ref()?)))
-    }
     pub fn var_offset(&self, var: VarID) -> Option<VarOffset> {
         let mut current = VarOffset { id: var, offset: 0 };
-        while let Some(parent) = self.var_defs[current.id.0].parent {
+        while let Some(parent) = self.get(current.id)?.parent {
             current.id = parent.var;
             current.offset += self.field_offset(parent.struc, parent.field)?;
         }
         Some(current)
     }
     pub fn field_offset(&self, struct_id: StructID, field: FieldID) -> Option<Len> {
-        let struc = self.get_struct(struct_id);
+        let struc = self.get(struct_id)?;
         let mut offset = 0;
         for i in 0..field.0 {
             offset += self.size_of_type(&struc.fields[i].ty)?;
         }
         Some(offset)
     }
+    pub fn iter_vars(&self) -> impl Iterator<Item = (VarID, &UVar)> {
+        self.vars
+            .iter()
+            .flatten()
+            .enumerate()
+            .map(|(i, x)| (ID::new(i), x))
+    }
+    pub fn iter_fns(&self) -> impl Iterator<Item = (FnID, &UFunc)> {
+        self.fns
+            .iter()
+            .flatten()
+            .enumerate()
+            .map(|(i, x)| (ID::new(i), x))
+    }
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Ident {
-    Var(VarID),
-    Fn(FnID),
-    Type(StructID),
+pub struct Ident {
+    id: usize,
+    kind: usize,
+}
+
+impl<K: Kind> From<ID<K>> for Ident {
+    fn from(id: ID<K>) -> Self {
+        Self {
+            id: id.0,
+            kind: K::INDEX,
+        }
+    }
 }
 
 #[derive(Debug, Clone, Copy)]
 pub struct Idents {
     pub latest: Ident,
-    pub var: Option<VarID>,
-    pub func: Option<FnID>,
-    pub struc: Option<StructID>,
+    pub kinds: [Option<usize>; NAMED_KINDS],
 }
 
 impl Idents {
     fn new(latest: Ident) -> Self {
         let mut s = Self {
             latest,
-            var: None,
-            func: None,
-            struc: None,
+            kinds: [None; NAMED_KINDS],
         };
         s.insert(latest);
         s
     }
     fn insert(&mut self, i: Ident) {
         self.latest = i;
-        match i {
-            Ident::Var(v) => {
-                self.var = Some(v);
-            }
-            Ident::Fn(f) => {
-                self.func = Some(f);
-            }
-            Ident::Type(t) => self.struc = Some(t),
-        }
+        self.kinds[i.kind] = Some(i.id);
+    }
+    pub fn get<K: Kind>(&self) -> Option<ID<K>> {
+        self.kinds[K::INDEX].map(|i| i.into())
     }
 }
diff --git a/src/ir/upper/ty.rs b/src/ir/upper/ty.rs
index 0a949d0..0fab315 100644
--- a/src/ir/upper/ty.rs
+++ b/src/ir/upper/ty.rs
@@ -1,4 +1,6 @@
-use super::{IRUProgram, Len, StructID};
+use crate::common::CompilerOutput;
+
+use super::{Len, StructID, UInstruction, UProgram, UVar};
 
 #[derive(Clone, PartialEq)]
 pub enum Type {
@@ -25,13 +27,121 @@ impl Type {
     }
 }
 
-// should impl instead
-pub fn resolve_types(ns: &IRUProgram) {
-    for (i, f) in ns.iter_fns() {
-        for inst in &f.instructions {
-            match &inst.i {
-                _ => todo!(),
+impl UProgram {
+    pub fn resolve_types(&mut self) {
+        // I LOVE RUST
+        let mut vars = self.vars.clone();
+        for f in self.fns.iter().flatten() {
+            for i in &f.instructions {
+                self.resolve_instr_types(&mut vars, &i.i);
             }
         }
+        self.vars = vars;
+    }
+
+    pub fn resolve_instr_types(&self, vars: &mut Vec<Option<UVar>>, i: &UInstruction) {
+        match &i {
+            UInstruction::Call { dest, f, args } => {
+                let ret = self.get_fn_var(f.id).expect("bruh").ret.clone();
+                vars[dest.id.0].as_mut().expect("bruh").ty = ret;
+            }
+            UInstruction::Mv { dest, src } => {
+                let dest_ty = &vars[dest.id.0].as_ref().unwrap().ty;
+                let src_ty = &vars[src.id.0].as_ref().unwrap().ty;
+                if let Some(ty) = match_types(dest_ty, src_ty) {
+                    vars[dest.id.0]
+                        .as_mut()
+                        .expect("PARTIAL BORROWING WOULD BE REALLY COOL")
+                        .ty = ty.clone();
+                    vars[src.id.0]
+                        .as_mut()
+                        .expect("PARTIAL BORROWING WOULD BE REALLY COOL")
+                        .ty = ty;
+                }
+            }
+            UInstruction::Ref { dest, src } => {
+                // TODO
+            }
+            UInstruction::LoadData { dest, src } => {
+                // TODO
+            }
+            UInstruction::LoadSlice { dest, src } => {
+                // TODO
+            }
+            UInstruction::LoadFn { dest, src } => {
+                // TODO
+            }
+            UInstruction::AsmBlock { instructions, args } => {
+                // TODO
+            }
+            UInstruction::Ret { .. } => {}
+            UInstruction::Construct { dest, fields } => {
+                // TODO
+            }
+            UInstruction::If { cond, body } => {
+                for i in body {
+                    self.resolve_instr_types(vars, &i.i);
+                }
+            }
+            UInstruction::Loop { body } => {
+                for i in body {
+                    self.resolve_instr_types(vars, &i.i);
+                }
+            }
+            UInstruction::Break => {}
+            UInstruction::Continue => {}
+        }
+    }
+}
+
+pub fn match_types(dest: &Type, src: &Type) -> Option<Type> {
+    if dest == src {
+        return None;
+    }
+    match (dest, src) {
+        (Type::Error, x) | (x, Type::Error) => None,
+        (Type::Infer, x) | (x, Type::Infer) => Some(x.clone()),
+        (
+            Type::Struct {
+                id: dest_id,
+                args: dest_args,
+            },
+            Type::Struct {
+                id: src_id,
+                args: src_args,
+            },
+        ) => {
+            if dest_id != src_id {
+                return None;
+            }
+            None
+            // TODO
+            // let mut args = Vec::new();
+            // for (darg, sarg) in dest_args.iter().zip(src_args) {
+            // }
+            // Some(Type::Struct { id: *dest_id, args })
+        }
+        (
+            Type::Fn {
+                args: dest_args,
+                ret: dest_ret,
+            },
+            Type::Fn {
+                args: src_args,
+                ret: src_ret,
+            },
+        ) => {
+            // TODO
+            None
+        }
+        (Type::Ref(dest), Type::Ref(src)) => Some(match_types(dest, src)?),
+        (Type::Slice(dest), Type::Slice(src)) => Some(match_types(dest, src)?),
+        (Type::Array(dest, dlen), Type::Array(src, slen)) => {
+            if dlen != slen {
+                return None;
+            }
+            match_types(dest, src)
+        }
+        _ => None,
     }
 }
diff --git a/src/ir/upper/validate.rs b/src/ir/upper/validate.rs
index 0cd88b9..2e658be 100644
--- a/src/ir/upper/validate.rs
+++ b/src/ir/upper/validate.rs
@@ -1,26 +1,27 @@
 // TODO: move this into ir, not parser
-use super::{IRUInstrInst, IRUInstruction, IRUProgram, Type};
+use super::{Type, UInstrInst, UInstruction, UProgram};
 use crate::common::{CompilerMsg, CompilerOutput, FileSpan};
 
-impl IRUProgram {
+impl UProgram {
     pub fn validate(&self) -> CompilerOutput {
         let mut output = CompilerOutput::new();
-        for (f, fd) in self.fns.iter().flatten().zip(&self.fn_defs) {
-            self.validate_fn(
-                &f.instructions,
-                fd.origin,
-                &fd.ret,
-                &mut output,
-                true,
-                false,
-            );
+        for f in self.fns.iter().flatten() {
+            self.validate_fn(&f.instructions, f.origin, &f.ret, &mut output, true, false);
+        }
+        for (id, var) in self.iter_vars() {
+            if var.ty == Type::Error {
+                output.err(CompilerMsg {
+                    msg: format!("Var {:?} is error type!", id),
+                    spans: vec![var.origin],
+                });
+            }
         }
         output
     }
 
     pub fn validate_fn(
         &self,
-        instructions: &[IRUInstrInst],
+        instructions: &[UInstrInst],
         origin: FileSpan,
         ret: &Type,
         output: &mut CompilerOutput,
@@ -30,31 +31,31 @@ impl IRUProgram {
         let mut no_ret = true;
         for i in instructions {
             match &i.i {
-                IRUInstruction::Mv { dest, src } => {
-                    let dest = self.get_var(dest.id);
-                    let src = self.get_var(src.id);
+                UInstruction::Mv { dest, src } => {
+                    let dest = self.expect(dest.id);
+                    let src = self.expect(src.id);
                     output.check_assign(self, &src.ty, &dest.ty, i.span);
                 }
-                IRUInstruction::Ref { dest, src } => {
+                UInstruction::Ref { dest, src } => {
                     // TODO
                 }
-                IRUInstruction::LoadData { dest, src } => {
-                    let dest = self.get_var(dest.id);
-                    let src = self.get_data(*src);
+                UInstruction::LoadData { dest, src } => {
+                    let dest = self.expect(dest.id);
+                    let src = self.expect(*src);
                     output.check_assign(self, &src.ty, &dest.ty, i.span);
                 }
-                IRUInstruction::LoadSlice { dest, src } => {
-                    let dest = self.get_var(dest.id);
-                    let src = self.get_data(*src);
+                UInstruction::LoadSlice { dest, src } => {
+                    let dest = self.expect(dest.id);
+                    let src = self.expect(*src);
                     let Type::Array(srcty, ..) = &src.ty else {
                         todo!()
                     };
                     output.check_assign(self, &Type::Slice(srcty.clone()), &dest.ty, i.span);
                 }
-                IRUInstruction::LoadFn { dest, src } => todo!(),
-                IRUInstruction::Call { dest, f, args } => {
-                    let destty = &self.get_var(dest.id).ty;
-                    let f = self.get_var(f.id);
+                UInstruction::LoadFn { dest, src } => todo!(),
+                UInstruction::Call { dest, f, args } => {
+                    let destty = &self.expect(dest.id).ty;
+                    let f = self.expect(f.id);
                     let Type::Fn { args: argtys, ret } = &f.ty else {
                         todo!()
                     };
@@ -65,21 +66,21 @@ impl IRUProgram {
                             spans: vec![dest.span],
                         });
                     }
-                    for (argv, argt) in args.iter().zip(argtys) {
-                        let dest = self.get_var(argv.id);
-                        output.check_assign(self, argt, &dest.ty, argv.span);
+                    for (dst_ty, src) in argtys.iter().zip(args) {
+                        let src_var = self.expect(src.id);
+                        output.check_assign(self, &src_var.ty, dst_ty, src.span);
                     }
                 }
-                IRUInstruction::AsmBlock { instructions, args } => {
+                UInstruction::AsmBlock { instructions, args } => {
                     // TODO
                 }
-                IRUInstruction::Ret { src } => {
-                    let srcty = &self.get_var(src.id).ty;
+                UInstruction::Ret { src } => {
+                    let srcty = &self.expect(src.id).ty;
                     output.check_assign(self, srcty, ret, src.span);
                     no_ret = false;
                 }
-                IRUInstruction::Construct { dest, fields } => {
-                    let dest_def = self.get_var(dest.id);
+                UInstruction::Construct { dest, fields } => {
+                    let dest_def = self.expect(dest.id);
                     let tyid = match &dest_def.ty {
                         Type::Struct { id, args } => *id,
                         _ => {
@@ -90,10 +91,10 @@ impl IRUProgram {
                             continue;
                         }
                     };
-                    let def = self.get_struct(tyid);
+                    let def = self.expect(tyid);
                     for (id, field) in def.iter_fields() {
                         if let Some(var) = fields.get(&id) {
-                            let ety = &self.get_var(var.id).ty;
+                            let ety = &self.expect(var.id).ty;
                             output.check_assign(self, &field.ty, ety, var.span);
                         } else {
                             output.err(CompilerMsg {
@@ -103,15 +104,15 @@ impl IRUProgram {
                         }
                     }
                 }
-                IRUInstruction::If { cond, body } => {
-                    let cond = self.get_var(cond.id);
+                UInstruction::If { cond, body } => {
+                    let cond = self.expect(cond.id);
                     output.check_assign(self, &cond.ty, &Type::Bits(64), i.span);
                     self.validate_fn(body, origin, ret, output, false, breakable);
                 }
-                IRUInstruction::Loop { body } => {
+                UInstruction::Loop { body } => {
                     self.validate_fn(body, origin, ret, output, false, true);
                 }
-                IRUInstruction::Break => {
+                UInstruction::Break => {
                     if !breakable {
                         output.err(CompilerMsg {
                             msg: "Can't break here (outside of loop)".to_string(),
@@ -120,7 +121,7 @@ impl IRUProgram {
                     }
                     // TODO
                 }
-                IRUInstruction::Continue => {
+                UInstruction::Continue => {
                     if !breakable {
                         output.err(CompilerMsg {
                             msg: "Can't continue here (outside of loop)".to_string(),
diff --git a/src/main.rs b/src/main.rs
index ddd68a0..0c5953e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,8 +5,9 @@
 // dawg what
 #![feature(str_as_str)]
 
-use ir::{IRLProgram, IRUProgram};
+use ir::{LProgram, UProgram};
 use parser::{NodeParsable, PModule, PStatement, ParserCtx};
+use util::Labelable;
 use std::{
     fs::{create_dir_all, OpenOptions},
     io::{stdout, BufRead, BufReader},
@@ -37,37 +38,45 @@ fn main() {
 fn run_file(file: &str, gdb: bool, asm: bool) {
     let mut ctx = ParserCtx::from(file);
     let res = PModule::parse_node(&mut ctx);
-    if ctx.output.errs.is_empty() {
-        println!("Parsed:");
-        println!("{:#?}", res.node);
-        if let Some(module) = res.node.as_ref() {
-            let mut program = IRUProgram::new();
-            module.lower(&mut program, &mut ctx.output);
-            if ctx.output.errs.is_empty() {
-                // println!("vars:");
-                // for (id, def) in namespace.iter_vars() {
-                //     println!("    {id:?} = {}: {}", def.name, namespace.type_name(&def.ty));
-                // }
-                // for (id, f) in namespace.iter_fns() {
-                //     println!("{id:?} = {:#?}", f.unwrap());
-                // }
-                let output = program.validate();
-                output.write_for(&mut stdout(), file);
-                if output.errs.is_empty() {
-                    let program = IRLProgram::create(&program).expect("morir");
-                    let unlinked = compiler::compile(&program);
-                    if asm {
-                        println!("{:?}", unlinked);
-                    } else {
-                        let bin = unlinked.link().to_elf();
-                        println!("compiled");
-                        save_run(&bin, gdb);
-                    }
-                }
-            }
+    let mut output = ctx.output;
+    'outer: {
+        if !output.errs.is_empty() {
+            break 'outer;
+        }
+        // println!("Parsed:");
+        // println!("{:#?}", res.node);
+        let Some(module) = res.node.as_ref() else {
+            break 'outer;
+        };
+        let mut program = UProgram::new();
+        module.lower(&mut program, &mut output);
+        if !output.errs.is_empty() {
+            break 'outer;
+        }
+        program.resolve_types();
+        // println!("vars:");
+        // for (id, def) in program.iter_vars() {
+        //     println!("    {id:?} = {}: {}", program.names.get(id), program.type_name(&def.ty));
+        // }
+        // for (id, f) in program.iter_fns() {
+        //     println!("{}:{id:?} = {:#?}", program.names.get(id), f);
+        // }
+        output = program.validate();
+        if !output.errs.is_empty() {
+            break 'outer;
+        }
+        output.write_for(&mut stdout(), file);
+        let program = LProgram::create(&program).expect("morir");
+        let unlinked = compiler::compile(&program);
+        if asm {
+            println!("{:?}", unlinked);
+        } else {
+            let bin = unlinked.link().to_elf();
+            println!("compiled");
+            save_run(&bin, gdb);
         }
     }
-    ctx.output.write_for(&mut stdout(), file);
+    output.write_for(&mut stdout(), file);
 }
 
 fn save_run(binary: &[u8], run_gdb: bool) {
diff --git a/src/parser/v3/lower/asm.rs b/src/parser/v3/lower/asm.rs
index 239fb09..ebe3c2f 100644
--- a/src/parser/v3/lower/asm.rs
+++ b/src/parser/v3/lower/asm.rs
@@ -1,7 +1,7 @@
 use crate::{
     compiler::arch::riscv::Reg,
     ir::{
-        arch::riscv64::RV64Instruction, AsmBlockArg, AsmBlockArgType, IRUInstruction, Type, VarInst,
+        arch::riscv64::RV64Instruction, AsmBlockArg, AsmBlockArgType, UInstruction, Type, VarInst,
     },
     parser::PAsmBlockArg,
 };
@@ -48,7 +48,7 @@ impl FnLowerable for PAsmBlock {
                 }
             }
         }
-        let block = IRUInstruction::AsmBlock {
+        let block = UInstruction::AsmBlock {
             instructions: {
                 let mut v = Vec::new();
                 for i in &self.instructions {
diff --git a/src/parser/v3/lower/block.rs b/src/parser/v3/lower/block.rs
index b3f7701..a649c83 100644
--- a/src/parser/v3/lower/block.rs
+++ b/src/parser/v3/lower/block.rs
@@ -1,4 +1,4 @@
-use crate::ir::{IRUInstruction, Type, VarInst};
+use crate::ir::{Type, UInstruction, VarInst};
 
 use super::{FnLowerCtx, FnLowerable, PBlock, PStatement};
 
@@ -23,17 +23,20 @@ impl FnLowerable for PStatement {
                 let def = def.lower(ctx.program, ctx.output)?;
                 let res = e.lower(ctx);
                 if let Some(res) = res {
-                    ctx.program.name_var(&def, res.id);
+                    ctx.push(UInstruction::Mv {
+                        dest: def,
+                        src: res,
+                    });
                 }
                 None
             }
             super::PStatement::Return(e) => {
                 if let Some(e) = e {
                     let src = e.lower(ctx)?;
-                    ctx.push_at(IRUInstruction::Ret { src }, src.span);
+                    ctx.push_at(UInstruction::Ret { src }, src.span);
                 } else {
                     let src = ctx.temp(Type::Unit);
-                    ctx.push_at(IRUInstruction::Ret { src }, src.span);
+                    ctx.push_at(UInstruction::Ret { src }, src.span);
                 }
                 None
             }
diff --git a/src/parser/v3/lower/def.rs b/src/parser/v3/lower/def.rs
index 82e2c31..45cff8a 100644
--- a/src/parser/v3/lower/def.rs
+++ b/src/parser/v3/lower/def.rs
@@ -1,26 +1,35 @@
-use crate::ir::{IRUProgram, Origin, Type, VarDef};
+use crate::ir::{Type, UProgram, UStruct, UVar, VarInst};
 
 use super::{CompilerMsg, CompilerOutput, FileSpan, Node, PType, PVarDef};
 
 impl Node<PVarDef> {
-    pub fn lower(&self, program: &mut IRUProgram, output: &mut CompilerOutput) -> Option<VarDef> {
+    pub fn lower(&self, program: &mut UProgram, output: &mut CompilerOutput) -> Option<VarInst> {
         let s = self.as_ref()?;
-        let name = s.name.as_ref()?.to_string();
+        let name = s
+            .name
+            .as_ref()
+            .map(|n| n.to_string())
+            .unwrap_or("{error}".to_string());
         let ty = match &s.ty {
             Some(ty) => ty.lower(program, output),
             None => Type::Infer,
         };
-        Some(VarDef {
-            name,
-            ty,
-            parent: None,
-            origin: self.span,
+        Some(VarInst {
+            id: program.def_searchable(
+                name,
+                Some(UVar {
+                    ty,
+                    parent: None,
+                    origin: self.span,
+                }),
+            ),
+            span: self.span,
         })
     }
 }
 
 impl Node<PType> {
-    pub fn lower(&self, namespace: &mut IRUProgram, output: &mut CompilerOutput) -> Type {
+    pub fn lower(&self, namespace: &mut UProgram, output: &mut CompilerOutput) -> Type {
         self.as_ref()
             .map(|t| t.lower(namespace, output, self.span))
             .unwrap_or(Type::Error)
@@ -30,14 +39,17 @@ impl Node<PType> {
 impl PType {
     pub fn lower(
         &self,
-        namespace: &mut IRUProgram,
+        namespace: &mut UProgram,
         output: &mut CompilerOutput,
         span: FileSpan,
     ) -> Type {
         let Some(name) = self.name.as_ref() else {
             return Type::Error;
         };
-        match namespace.get(&name).and_then(|ids| ids.struc) {
+        match namespace
+            .get_idents(name)
+            .and_then(|ids| ids.get::<UStruct>())
+        {
             Some(id) => {
                 let args = self
                     .args
diff --git a/src/parser/v3/lower/expr.rs b/src/parser/v3/lower/expr.rs
index 69e52bc..76f82d5 100644
--- a/src/parser/v3/lower/expr.rs
+++ b/src/parser/v3/lower/expr.rs
@@ -1,6 +1,6 @@
 use super::{func::FnLowerCtx, FnLowerable, PExpr, UnaryOp};
 use crate::{
-    ir::{DataDef, FieldRef, IRUInstruction, Type, VarInst},
+    ir::{FieldRef, Type, UData, UInstruction, VarInst},
     parser::PInfixOp,
 };
 
@@ -12,55 +12,53 @@ impl FnLowerable for PExpr {
                 super::PLiteral::String(s) => {
                     let dest = ctx.program.temp_var(l.span, Type::Bits(8).slice());
                     let data = s.as_bytes().to_vec();
-                    let src = ctx.program.def_data(
-                        DataDef {
+                    let src = ctx.program.def(
+                        format!("string \"{}\"", s.replace("\n", "\\n")),
+                        Some(UData {
                             ty: Type::Bits(8).arr(data.len() as u32),
                             origin: l.span,
-                            label: format!("string \"{}\"", s.replace("\n", "\\n")),
-                        },
-                        data,
+                            content: data,
+                        }),
                     );
-                    ctx.push(IRUInstruction::LoadSlice { dest, src });
+                    ctx.push(UInstruction::LoadSlice { dest, src });
                     dest
                 }
                 super::PLiteral::Char(c) => {
                     let ty = Type::Bits(8);
                     let dest = ctx.program.temp_var(l.span, ty.clone());
-                    let src = ctx.program.def_data(
-                        DataDef {
+                    let src = ctx.program.def(
+                        format!("char '{c}'"),
+                        Some(UData {
                             ty,
                             origin: l.span,
-                            label: format!("char '{c}'"),
-                        },
-                        c.to_string().as_bytes().to_vec(),
+                            content: c.to_string().as_bytes().to_vec(),
+                        }),
                     );
-                    ctx.push(IRUInstruction::LoadData { dest, src });
+                    ctx.push(UInstruction::LoadData { dest, src });
                     dest
                 }
                 super::PLiteral::Number(n) => {
                     // TODO: temp
                     let ty = Type::Bits(64);
                     let dest = ctx.program.temp_var(l.span, Type::Bits(64));
-                    let src = ctx.program.def_data(
-                        DataDef {
+                    let src = ctx.program.def(
+                        format!("num {n:?}"),
+                        Some(UData {
                             ty,
                             origin: l.span,
-                            label: format!("num {n:?}"),
-                        },
-                        n.whole.parse::<i64>().unwrap().to_le_bytes().to_vec(),
+                            content: n.whole.parse::<i64>().unwrap().to_le_bytes().to_vec(),
+                        }),
                     );
-                    ctx.push(IRUInstruction::LoadData { dest, src });
+                    ctx.push(UInstruction::LoadData { dest, src });
                     dest
                 }
-                super::PLiteral::Unit => {
-                    todo!();
-                }
+                super::PLiteral::Unit => ctx.program.temp_var(l.span, Type::Unit),
             },
             PExpr::Ident(i) => ctx.get_var(i)?,
             PExpr::BinaryOp(op, e1, e2) => {
                 let res1 = e1.lower(ctx)?;
                 if *op == PInfixOp::Access {
-                    let sty = &ctx.program.get_var(res1.id).ty;
+                    let sty = &ctx.program.expect(res1.id).ty;
                     let Type::Struct {
                         id: struct_id,
                         args,
@@ -72,7 +70,7 @@ impl FnLowerable for PExpr {
                         ));
                         return None;
                     };
-                    let struc = ctx.program.get_struct(*struct_id);
+                    let struc = ctx.program.expect(*struct_id);
                     let Some(box PExpr::Ident(ident)) = &e2.inner else {
                         ctx.err("Field accesses must be identifiers".to_string());
                         return None;
@@ -102,7 +100,7 @@ impl FnLowerable for PExpr {
                         PInfixOp::GreaterThan => todo!(),
                         PInfixOp::Access => todo!(),
                         PInfixOp::Assign => {
-                            ctx.push(IRUInstruction::Mv {
+                            ctx.push(UInstruction::Mv {
                                 dest: res1,
                                 src: res2,
                             });
@@ -115,15 +113,15 @@ impl FnLowerable for PExpr {
                 let res = e.lower(ctx)?;
                 match op {
                     UnaryOp::Ref => {
-                        let temp = ctx.temp(ctx.program.get_var(res.id).ty.clone().rf());
-                        ctx.push(IRUInstruction::Ref {
+                        let temp = ctx.temp(ctx.program.expect(res.id).ty.clone().rf());
+                        ctx.push(UInstruction::Ref {
                             dest: temp,
                             src: res,
                         });
                         temp
                     }
                     UnaryOp::Deref => {
-                        let t = &ctx.program.get_var(res.id).ty;
+                        let t = &ctx.program.expect(res.id).ty;
                         let Type::Ref(inner) = t else {
                             ctx.err(format!(
                                 "Cannot dereference type {:?}",
@@ -145,22 +143,13 @@ impl FnLowerable for PExpr {
                     let arg = arg.lower(ctx)?;
                     nargs.push(arg);
                 }
-                let def = ctx.program.get_fn_var(fe.id);
-                let ty = match def {
-                    Some(def) => def.ret.clone(),
-                    None => {
-                        ctx.err_at(
-                            e.span,
-                            format!(
-                                "Expected function, found {}",
-                                ctx.program.type_name(&ctx.program.get_var(fe.id).ty)
-                            ),
-                        );
-                        Type::Error
-                    }
-                };
+                let ty = ctx
+                    .program
+                    .get_fn_var(fe.id)
+                    .map(|f| f.ret.clone())
+                    .unwrap_or(Type::Error);
                 let temp = ctx.temp(ty);
-                ctx.push(IRUInstruction::Call {
+                ctx.push(UInstruction::Call {
                     dest: temp,
                     f: fe,
                     args: nargs,
@@ -176,7 +165,7 @@ impl FnLowerable for PExpr {
                 body.lower(&mut body_ctx);
                 let body = body_ctx.instructions;
                 ctx.program.pop();
-                ctx.push(IRUInstruction::If { cond, body });
+                ctx.push(UInstruction::If { cond, body });
                 return None;
             }
             PExpr::Loop(body) => {
@@ -185,15 +174,15 @@ impl FnLowerable for PExpr {
                 body.lower(&mut body_ctx);
                 let body = body_ctx.instructions;
                 ctx.program.pop();
-                ctx.push(IRUInstruction::Loop { body });
+                ctx.push(UInstruction::Loop { body });
                 return None;
             }
             PExpr::Break => {
-                ctx.push(IRUInstruction::Break);
+                ctx.push(UInstruction::Break);
                 return None;
             }
             PExpr::Continue => {
-                ctx.push(IRUInstruction::Continue);
+                ctx.push(UInstruction::Continue);
                 return None;
             }
         })
diff --git a/src/parser/v3/lower/func.rs b/src/parser/v3/lower/func.rs
index 5a2f354..416f3d4 100644
--- a/src/parser/v3/lower/func.rs
+++ b/src/parser/v3/lower/func.rs
@@ -1,110 +1,102 @@
 use super::{CompilerMsg, CompilerOutput, FileSpan, FnLowerable, Node, PFunction};
 use crate::{
-    ir::{
-        FnDef, FnID, IRUFunction, IRUInstrInst, IRUInstruction, IRUProgram, Idents, Type, VarDef,
-        VarInst, FieldRef,
-    },
+    ir::{FieldRef, FnID, Idents, Type, UFunc, UInstrInst, UInstruction, UProgram, UVar, VarInst},
     parser,
 };
 
 impl Node<PFunction> {
-    pub fn lower_header(&self, map: &mut IRUProgram, output: &mut CompilerOutput) -> Option<FnID> {
-        self.as_ref()?.lower_header(map, output)
+    pub fn lower_name(&self, p: &mut UProgram) -> Option<FnID> {
+        Some(self.as_ref()?.lower_name(p)?)
     }
-    pub fn lower_body(
-        &self,
-        id: FnID,
-        map: &mut IRUProgram,
-        output: &mut CompilerOutput,
-    ) -> Option<IRUFunction> {
-        Some(self.as_ref()?.lower_body(id, map, output))
+    pub fn lower(&self, id: FnID, p: &mut UProgram, output: &mut CompilerOutput) {
+        if let Some(s) = self.as_ref() {
+            s.lower(id, p, output)
+        }
     }
 }
 
 impl PFunction {
-    pub fn lower_header(&self, map: &mut IRUProgram, output: &mut CompilerOutput) -> Option<FnID> {
+    pub fn lower_name(&self, p: &mut UProgram) -> Option<FnID> {
         let header = self.header.as_ref()?;
         let name = header.name.as_ref()?;
-        let args = header
-            .args
-            .iter()
-            .map(|a| {
-                a.lower(map, output).unwrap_or(VarDef {
-                    name: "{error}".to_string(),
-                    origin: a.span,
-                    parent: None,
-                    ty: Type::Error,
-                })
-            })
-            .collect();
-        let ret = match &header.ret {
-            Some(ty) => ty.lower(map, output),
-            None => Type::Unit,
-        };
-        Some(map.def_fn(FnDef {
-            name: name.to_string(),
-            origin: self.header.span,
-            args,
-            ret,
-        }))
+        let id = p.def_searchable(name.to_string(), None);
+        let var = p.def_searchable(
+            name.to_string(),
+            Some(UVar {
+                parent: None,
+                ty: Type::Error,
+                origin: self.header.span,
+            }),
+        );
+        p.fn_map.insert(var, id);
+        p.inv_fn_map.push(var);
+        Some(id)
     }
-    pub fn lower_body(
-        &self,
-        id: FnID,
-        map: &mut IRUProgram,
-        output: &mut CompilerOutput,
-    ) -> IRUFunction {
-        let def = map.get_fn(id).clone();
-        let args = def.args.iter().map(|a| map.named_var(a.clone())).collect();
+    pub fn lower(&self, id: FnID, p: &mut UProgram, output: &mut CompilerOutput) {
+        let (args, ret) = if let Some(header) = self.header.as_ref() {
+            (
+                header
+                    .args
+                    .iter()
+                    .flat_map(|a| Some(a.lower(p, output)?.id))
+                    .collect(),
+                match &header.ret {
+                    Some(ty) => ty.lower(p, output),
+                    None => Type::Unit,
+                },
+            )
+        } else {
+            (Vec::new(), Type::Error)
+        };
         let mut ctx = FnLowerCtx {
             instructions: Vec::new(),
-            program: map,
+            program: p,
             output,
             span: self.body.span,
         };
         if let Some(src) = self.body.lower(&mut ctx) {
-            ctx.instructions.push(IRUInstrInst {
-                i: IRUInstruction::Ret { src },
+            ctx.instructions.push(UInstrInst {
+                i: UInstruction::Ret { src },
                 span: src.span,
             });
         }
-        IRUFunction {
-            name: def.name.clone(),
+        let origin = self.header.span;
+        let f = UFunc {
+            origin,
             args,
-            ret: def.ret,
+            ret,
             instructions: ctx.instructions,
-        }
+        };
+        p.expect_mut(p.inv_fn_map[id.0]).ty = f.ty(p);
+        p.write(id, f)
     }
 }
 
 pub struct FnLowerCtx<'a> {
-    pub program: &'a mut IRUProgram,
-    pub instructions: Vec<IRUInstrInst>,
+    pub program: &'a mut UProgram,
+    pub instructions: Vec<UInstrInst>,
     pub output: &'a mut CompilerOutput,
     pub span: FileSpan,
 }
 
 impl FnLowerCtx<'_> {
-    pub fn get(&mut self, node: &Node<parser::PIdent>) -> Option<Idents> {
+    pub fn get_idents(&mut self, node: &Node<parser::PIdent>) -> Option<Idents> {
         let name = node.inner.as_ref()?;
-        let res = self.program.get(name);
+        let res = self.program.get_idents(name);
         if res.is_none() {
             self.err_at(node.span, format!("Identifier '{}' not found", name));
         }
         res
     }
     pub fn get_var(&mut self, node: &Node<parser::PIdent>) -> Option<VarInst> {
-        let ids = self.get(node)?;
-        if ids.var.is_none() {
+        let ids = self.get_idents(node)?;
+        if ids.get::<UVar>().is_none() {
             self.err_at(
                 node.span,
-                format!(
-                    "Variable '{}' not found; Type found but cannot be used here",
-                    node.inner.as_ref()?
-                ),
+                format!("Variable '{}' not found", node.inner.as_ref()?),
             );
         }
-        ids.var.map(|id| VarInst {
+        ids.get::<UVar>().map(|id| VarInst {
             id,
             span: node.span,
         })
@@ -121,11 +113,11 @@ impl FnLowerCtx<'_> {
     pub fn temp_subvar(&mut self, ty: Type, parent: FieldRef) -> VarInst {
         self.program.temp_subvar(self.span, ty, parent)
     }
-    pub fn push(&mut self, i: IRUInstruction) {
-        self.instructions.push(IRUInstrInst { i, span: self.span });
+    pub fn push(&mut self, i: UInstruction) {
+        self.instructions.push(UInstrInst { i, span: self.span });
     }
-    pub fn push_at(&mut self, i: IRUInstruction, span: FileSpan) {
-        self.instructions.push(IRUInstrInst { i, span });
+    pub fn push_at(&mut self, i: UInstruction, span: FileSpan) {
+        self.instructions.push(UInstrInst { i, span });
     }
     pub fn branch<'a>(&'a mut self) -> FnLowerCtx<'a> {
         FnLowerCtx {
diff --git a/src/parser/v3/lower/module.rs b/src/parser/v3/lower/module.rs
index c9c5e4b..fc0c3f2 100644
--- a/src/parser/v3/lower/module.rs
+++ b/src/parser/v3/lower/module.rs
@@ -1,25 +1,25 @@
-use crate::ir::IRUProgram;
+use crate::ir::UProgram;
 
-use super::{PModule, CompilerOutput};
+use super::{CompilerOutput, PModule};
 
 impl PModule {
-    pub fn lower(&self, p: &mut IRUProgram, output: &mut CompilerOutput) {
+    pub fn lower(&self, p: &mut UProgram, output: &mut CompilerOutput) {
+        let mut structs = Vec::new();
         for s in &self.structs {
-            s.lower(p, output);
+            structs.push(s.lower_name(p));
+        }
+        for (s, id) in self.structs.iter().zip(structs) {
+            if let Some(id) = id {
+                s.lower(id, p, output);
+            }
         }
         let mut fns = Vec::new();
         for f in &self.functions {
-            if let Some(id) = f.lower_header(p, output) {
-                fns.push(Some(id));
-            } else {
-                fns.push(None)
-            }
+            fns.push(f.lower_name(p));
         }
         for (f, id) in self.functions.iter().zip(fns) {
             if let Some(id) = id {
-                if let Some(res) = f.lower_body(id, p, output) {
-                    p.write_fn(id, res);
-                }
+                f.lower(id, p, output)
             }
         }
     }
diff --git a/src/parser/v3/lower/struc.rs b/src/parser/v3/lower/struc.rs
index 82b2751..389e067 100644
--- a/src/parser/v3/lower/struc.rs
+++ b/src/parser/v3/lower/struc.rs
@@ -2,7 +2,7 @@ use std::collections::HashMap;
 
 use crate::{
     common::{CompilerOutput, FileSpan},
-    ir::{FieldID, IRUInstruction, IRUProgram, StructDef, StructField, Type, VarInst},
+    ir::{FieldID, StructField, StructID, Type, UInstruction, UProgram, UStruct, VarInst},
     parser::{Node, PConstruct, PConstructFields, PStruct, PStructFields},
 };
 
@@ -13,7 +13,7 @@ impl FnLowerable for PConstruct {
     fn lower(&self, ctx: &mut FnLowerCtx) -> Option<VarInst> {
         let ty = self.name.lower(ctx.program, ctx.output);
         let field_map = match ty {
-            Type::Struct { id, .. } => ctx.program.get_struct(id),
+            Type::Struct { id, .. } => ctx.program.expect(id),
             _ => {
                 ctx.err(format!(
                     "Type {} cannot be constructed",
@@ -62,7 +62,7 @@ impl FnLowerable for PConstruct {
             PConstructFields::None => Default::default(),
         };
         let id = ctx.temp(ty);
-        ctx.push(IRUInstruction::Construct { dest: id, fields });
+        ctx.push(UInstruction::Construct { dest: id, fields });
         Some(id)
     }
 }
@@ -70,7 +70,8 @@ impl FnLowerable for PConstruct {
 impl PStruct {
     pub fn lower(
         &self,
-        p: &mut IRUProgram,
+        id: StructID,
+        p: &mut UProgram,
         output: &mut CompilerOutput,
         span: FileSpan,
     ) -> Option<()> {
@@ -99,23 +100,30 @@ impl PStruct {
         .into_iter()
         .enumerate()
         .map(|(i, (name, ty))| {
-            let id = FieldID(i);
+            let id = FieldID::new(i);
             field_map.insert(name.clone(), id);
             StructField { name, ty }
         })
         .collect();
-        p.def_struct(StructDef {
-            name: self.name.as_ref()?.to_string(),
-            origin: span,
-            field_map,
-            fields,
-        });
+        p.write(
+            id,
+            UStruct {
+                origin: span,
+                field_map,
+                fields,
+            },
+        );
         Some(())
     }
 }
 
 impl Node<PStruct> {
-    pub fn lower(&self, p: &mut IRUProgram, output: &mut CompilerOutput) {
-        self.as_ref().map(|i| i.lower(p, output, self.span));
+    pub fn lower_name(&self, p: &mut UProgram) -> Option<StructID> {
+        let name = self.as_ref()?.name.as_ref()?.to_string();
+        let id = p.def_searchable(name.to_string(), None);
+        Some(id)
+    }
+    pub fn lower(&self, id: StructID, p: &mut UProgram, output: &mut CompilerOutput) {
+        self.as_ref().map(|i| i.lower(id, p, output, self.span));
     }
 }