INITIAL GENERICS IMPL

src/ir/lower/program.rs

@@ -1,10 +1,9 @@
 use std::collections::HashMap;
 
-use crate::ir::{AsmBlockArgType, UInstrInst, Size, SymbolSpace, UFunc, VarOffset};
+use crate::ir::{AsmBlockArgType, Size, SymbolSpace, UFunc, UInstrInst, VarOffset};
 
 use super::{
-    IRLFunction, LInstruction, Len, Symbol, SymbolSpaceBuilder, Type, UInstruction, UProgram,
-    VarID,
+    IRLFunction, LInstruction, Len, Symbol, SymbolSpaceBuilder, Type, UInstruction, UProgram, VarID,
 };
 
 pub struct LProgram {
@@ -43,12 +42,37 @@ impl LProgram {
     }
 }
 
+pub struct StructInst {
+    offsets: Vec<Len>,
+    order: HashMap<String, usize>,
+    size: Size,
+}
+
 pub struct LFunctionBuilder<'a> {
+    data: LFunctionBuilderData<'a>,
     program: &'a UProgram,
+}
+
+impl<'a> LFunctionBuilderData<'a> {
+    pub fn new(builder: &'a mut SymbolSpaceBuilder) -> Self {
+        Self {
+            instrs: Vec::new(),
+            struct_insts: HashMap::new(),
+            stack: HashMap::new(),
+            subvar_map: HashMap::new(),
+            makes_call: false,
+            builder,
+            loopp: None,
+        }
+    }
+}
+
+pub struct LFunctionBuilderData<'a> {
     builder: &'a mut SymbolSpaceBuilder,
     instrs: Vec<LInstruction>,
     stack: HashMap<VarID, Size>,
     subvar_map: HashMap<VarID, VarOffset>,
+    struct_insts: HashMap<Type, StructInst>,
     makes_call: bool,
     loopp: Option<LoopCtx>,
 }
@@ -62,29 +86,32 @@ pub struct LoopCtx {
 impl<'a> LFunctionBuilder<'a> {
     pub fn new(program: &'a UProgram, builder: &'a mut SymbolSpaceBuilder) -> Self {
         Self {
-            instrs: Vec::new(),
-            stack: HashMap::new(),
-            subvar_map: HashMap::new(),
-            makes_call: false,
+            data: LFunctionBuilderData::new(builder),
             program,
-            builder,
-            loopp: None,
         }
     }
     pub fn alloc_stack(&mut self, i: VarID) -> Option<()> {
-        if self.program.size_of_var(i).expect("unsized type") == 0 {
+        if self
+            .data
+            .size_of_var(self.program, i)
+            .expect("unsized type")
+            == 0
+        {
             return None;
         };
         self.map_subvar(i);
-        let var = self.program.var_offset(i).expect("var offset");
-        *self
-            .stack
-            .entry(var.id)
-            .or_insert(self.program.size_of_var(var.id).expect("unsized type"));
+        let var = self.data.var_offset(self.program, i).expect("var offset");
+        if let None = self.stack.get(&var.id) {
+            let size = self
+                .data
+                .size_of_var(self.program, var.id)
+                .expect("unsized type");
+            self.data.stack.insert(var.id, size);
+        }
         Some(())
     }
     pub fn map_subvar(&mut self, i: VarID) {
-        let off = self.program.var_offset(i).expect("var offset");
+        let off = self.data.var_offset(self.program, i).expect("var offset");
         if off.id != i {
             self.subvar_map.insert(i, off);
         }
@@ -112,7 +139,7 @@ impl<'a> LFunctionBuilder<'a> {
             UInstruction::LoadData { dest, src } => {
                 self.alloc_stack(dest.id)?;
                 let data = self.program.expect(*src);
-                let sym = self.builder.ro_data(
+                let sym = self.data.builder.ro_data(
                     src,
                     &data.content,
                     Some(self.program.names.get(dest.id).to_string()),
@@ -133,7 +160,7 @@ impl<'a> LFunctionBuilder<'a> {
                         self.program.type_name(&data.ty)
                     )));
                 };
-                let sym = self.builder.ro_data(
+                let sym = self.data.builder.ro_data(
                     src,
                     &data.content,
                     Some(self.program.names.get(dest.id).to_string()),
@@ -168,7 +195,10 @@ impl<'a> LFunctionBuilder<'a> {
                 self.makes_call = true;
                 let fid = &self.program.fn_map[&f.id];
                 let sym = self.builder.func(fid);
-                let ret_size = self.program.size_of_var(dest.id).expect("unsized type");
+                let ret_size = self
+                    .data
+                    .size_of_var(self.program, dest.id)
+                    .expect("unsized type");
                 let dest = if ret_size > 0 {
                     Some((dest.id, ret_size))
                 } else {
@@ -181,7 +211,12 @@ impl<'a> LFunctionBuilder<'a> {
                         .iter()
                         .map(|a| {
                             self.map_subvar(a.id);
-                            (a.id, self.program.size_of_var(a.id).expect("unsized type"))
+                            (
+                                a.id,
+                                self.data
+                                    .size_of_var(self.program, a.id)
+                                    .expect("unsized type"),
+                            )
                         })
                         .collect(),
                 };
@@ -210,31 +245,32 @@ impl<'a> LFunctionBuilder<'a> {
             }
             UInstruction::Ret { src } => {
                 self.map_subvar(src.id);
-                self.instrs.push(LInstruction::Ret {
-                    src: if self.program.size_of_var(src.id).expect("unsized var") == 0 {
-                        None
-                    } else {
-                        Some(src.id)
-                    },
-                })
+                let src = if self
+                    .data
+                    .size_of_var(self.program, src.id)
+                    .expect("unsized var")
+                    == 0
+                {
+                    None
+                } else {
+                    Some(src.id)
+                };
+                self.data.instrs.push(LInstruction::Ret { src })
             }
             UInstruction::Construct { dest, fields } => {
                 self.alloc_stack(dest.id)?;
-                let ty = &self.program.expect(dest.id).ty;
-                let &Type::Struct { id, ref args } = ty else {
-                    return Some(Some(format!(
-                        "Failed to contruct type {}",
-                        self.program.type_name(ty)
-                    )));
-                };
-                for (&fid, var) in fields {
+                for (field, var) in fields {
                     self.map_subvar(var.id);
-                    self.instrs.push(LInstruction::Mv {
+                    let i = LInstruction::Mv {
                         dest: dest.id,
                         src: var.id,
-                        dest_offset: self.program.field_offset(id, fid).expect("field offset"),
+                        dest_offset: self
+                            .data
+                            .field_offset(self.program, dest.id, field)
+                            .expect("field offset"),
                         src_offset: 0,
-                    })
+                    };
+                    self.instrs.push(i)
                 }
             }
             UInstruction::If { cond, body } => {
@@ -266,35 +302,146 @@ impl<'a> LFunctionBuilder<'a> {
                 self.loopp = old;
             }
             UInstruction::Break => {
-                self.instrs.push(LInstruction::Jump(
-                    self.loopp.expect("Tried to break outside of loop").bot,
+                self.data.instrs.push(LInstruction::Jump(
+                    self.data.loopp.expect("Tried to break outside of loop").bot,
                 ));
             }
             UInstruction::Continue => {
-                self.instrs.push(LInstruction::Jump(
-                    self.loopp.expect("Tried to break outside of loop").top,
+                self.data.instrs.push(LInstruction::Jump(
+                    self.data.loopp.expect("Tried to break outside of loop").top,
                 ));
             }
         };
         Some(None)
     }
 
-    pub fn finish(self, f: &UFunc) -> IRLFunction {
+    pub fn finish(mut self, f: &UFunc) -> IRLFunction {
         IRLFunction {
-            instructions: self.instrs,
-            makes_call: self.makes_call,
             args: f
                 .args
                 .iter()
-                .map(|a| (*a, self.program.size_of_var(*a).expect("unsized type")))
+                .map(|a| {
+                    (
+                        *a,
+                        self.data
+                            .size_of_var(self.program, *a)
+                            .expect("unsized type"),
+                    )
+                })
                 .collect(),
-            ret_size: self.program.size_of_type(&f.ret).expect("unsized type"),
-            stack: self.stack,
-            subvar_map: self.subvar_map,
+            ret_size: self
+                .data
+                .size_of_type(self.program, &f.ret)
+                .expect("unsized type"),
+            instructions: self.data.instrs,
+            makes_call: self.data.makes_call,
+            stack: self.data.stack,
+            subvar_map: self.data.subvar_map,
         }
     }
 }
 
+impl LFunctionBuilderData<'_> {
+    pub fn var_offset(&mut self, p: &UProgram, var: VarID) -> Option<VarOffset> {
+        let mut current = VarOffset { id: var, offset: 0 };
+        while let Some(parent) = &p.get(current.id)?.parent {
+            current.id = parent.var;
+            current.offset += self.field_offset(p, parent.var, &parent.field)?;
+        }
+        Some(current)
+    }
+    pub fn addr_size(&self) -> Size {
+        64
+    }
+    pub fn struct_inst(&mut self, p: &UProgram, ty: &Type) -> Option<&StructInst> {
+        // normally I'd let Some(..) here and return, but polonius does not exist :grief:
+        if self.struct_insts.get(ty).is_none() {
+            let Type::Struct { id, args } = ty else {
+                return None;
+            };
+            let struc = p.get(*id)?;
+            let mut sizes = struc
+                .fields
+                .iter()
+                .map(|(n, f)| {
+                    let ty = if let Type::Generic { id } = &f.ty {
+                        struc
+                            .generics
+                            .iter()
+                            .enumerate()
+                            .find_map(|(i, g)| if *g == *id { args.get(i) } else { None })
+                            .unwrap_or(&f.ty)
+                    } else {
+                        &f.ty
+                    };
+                    (n, self.size_of_type(p, ty).expect("unsized type"))
+                })
+                .collect::<Vec<_>>();
+            sizes.sort_by(|(n1, s1, ..), (n2, s2, ..)| s1.cmp(s2).then_with(|| n1.cmp(n2)));
+            let mut offset = 0;
+            let mut offsets = Vec::new();
+            let mut order = HashMap::new();
+            for (i, (name, size)) in sizes.iter().rev().enumerate() {
+                // TODO: alignment!!!
+                order.insert(name.to_string(), i);
+                offsets.push(offset);
+                offset += size;
+            }
+            self.struct_insts.insert(
+                ty.clone(),
+                StructInst {
+                    offsets,
+                    order,
+                    size: offset,
+                },
+            );
+        }
+        self.struct_insts.get(ty)
+    }
+
+    pub fn field_offset(&mut self, p: &UProgram, var: VarID, field: &str) -> Option<Len> {
+        let ty = &p.get(var)?.ty;
+        let inst = self.struct_inst(p, ty)?;
+        let i = *inst.order.get(field)?;
+        Some(*inst.offsets.get(i)?)
+    }
+
+    pub fn size_of_type(&mut self, p: &UProgram, ty: &Type) -> Option<Size> {
+        // TODO: target matters
+        Some(match ty {
+            Type::Bits(b) => *b,
+            Type::Struct { id, args } => self.struct_inst(p, ty)?.size,
+            Type::Generic { id } => return None,
+            Type::Fn { args, ret } => todo!(),
+            Type::Ref(_) => self.addr_size(),
+            Type::Array(ty, len) => self.size_of_type(p, ty)? * len,
+            Type::Slice(_) => self.addr_size() * 2,
+            Type::Infer => return None,
+            Type::Error => return None,
+            Type::Unit => 0,
+            Type::Placeholder => return None,
+        })
+    }
+
+    pub fn size_of_var(&mut self, p: &UProgram, var: VarID) -> Option<Size> {
+        self.size_of_type(p, &p.get(var)?.ty)
+    }
+}
+
+impl<'a> std::ops::Deref for LFunctionBuilder<'a> {
+    type Target = LFunctionBuilderData<'a>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.data
+    }
+}
+
+impl<'a> std::ops::DerefMut for LFunctionBuilder<'a> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.data
+    }
+}
+
 impl std::ops::Deref for LProgram {
     type Target = SymbolSpace;
 

src/ir/upper/error.rs

@@ -3,9 +3,12 @@ use crate::common::{CompilerMsg, CompilerOutput, FileSpan};
 use super::{Type, UProgram};
 
 impl CompilerOutput {
-    pub fn check_assign(&mut self, p: &UProgram, src: &Type, dest: &Type, span: FileSpan) -> bool {
+    pub fn check_assign(&mut self, p: &UProgram, src: &Type, dest: &Type, span: FileSpan) {
         // TODO: spans
         if src != dest {
+            if !src.is_real() || !dest.is_real() {
+                return;
+            }
             self.err(CompilerMsg {
                 msg: format!(
                     "Cannot assign type '{}' to '{}'",
@@ -14,9 +17,6 @@ impl CompilerOutput {
                 ),
                 spans: vec![span],
             });
-            true
-        } else {
-            false
         }
     }
 }

src/ir/upper/instr.rs

@@ -1,7 +1,7 @@
 use std::{collections::HashMap, fmt::Write};
 
-use super::{arch::riscv64::RV64Instruction, inst::VarInst, DataID, FnID, UInstrInst, UFunc};
-use crate::{compiler::arch::riscv::Reg, ir::FieldID, util::Padder};
+use super::{arch::riscv64::RV64Instruction, inst::VarInst, DataID, FnID, UFunc, UInstrInst};
+use crate::{compiler::arch::riscv::Reg, util::Padder};
 
 pub enum UInstruction {
     Mv {
@@ -38,7 +38,7 @@ pub enum UInstruction {
     },
     Construct {
         dest: VarInst,
-        fields: HashMap<FieldID, VarInst>,
+        fields: HashMap<String, VarInst>,
     },
     If {
         cond: VarInst,

src/ir/upper/kind.rs

@@ -3,11 +3,9 @@ use crate::{
     ir::{Len, Named, ID},
 };
 
-use super::{Type, UInstrInst, UProgram};
+use super::{Type, UInstrInst, UInstruction, UProgram};
 use std::{collections::HashMap, fmt::Debug};
 
-pub const NAMED_KINDS: usize = 4;
-
 pub struct UFunc {
     pub args: Vec<VarID>,
     pub ret: Type,
@@ -17,17 +15,19 @@ pub struct UFunc {
 
 #[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 fields: HashMap<String, StructField>,
+    pub generics: Vec<GenericID>,
     pub origin: Origin,
 }
 
+#[derive(Clone)]
+pub struct UGeneric {}
+
 #[derive(Clone)]
 pub struct UVar {
     pub parent: Option<FieldRef>,
@@ -41,13 +41,10 @@ pub struct VarOffset {
     pub offset: Len,
 }
 
-#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
+#[derive(Debug, Clone, 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,
+    pub field: String,
 }
 
 #[derive(Clone)]
@@ -70,84 +67,68 @@ impl UFunc {
             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 fn flat_iter(&self) -> impl Iterator<Item = &UInstrInst> {
+        InstrIter::new(self.instructions.iter())
     }
 }
 
-pub type StructID = ID<UStruct>;
-pub type VarID = ID<UVar>;
-pub type DataID = ID<UData>;
-pub type FieldID = ID<StructField>;
+pub struct InstrIter<'a> {
+    iters: Vec<core::slice::Iter<'a, UInstrInst>>,
+}
+
+impl<'a> InstrIter<'a> {
+    pub fn new(iter: core::slice::Iter<'a, UInstrInst>) -> Self {
+        Self { iters: vec![iter] }
+    }
+}
+
+impl<'a> Iterator for InstrIter<'a> {
+    type Item = &'a UInstrInst;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let iter = self.iters.last_mut()?;
+        let Some(next) = iter.next() else {
+            self.iters.pop();
+            return self.next();
+        };
+        match &next.i {
+            UInstruction::Loop { body } => self.iters.push(body.iter()),
+            UInstruction::If { cond: _, body } => self.iters.push(body.iter()),
+            _ => (),
+        }
+        Some(next)
+    }
+}
+
+macro_rules! impl_kind {
+    ($struc:ty, $idx:expr, $field:ident, $name:expr) => {
+        impl Kind for $struc {
+            const INDEX: usize = $idx;
+            fn from_program_mut(program: &mut UProgram) -> &mut Vec<Option<Self>> {
+                &mut program.$field
+            }
+            fn from_program(program: &UProgram) -> &Vec<Option<Self>> {
+                &program.$field
+            }
+        }
+        impl Named for $struc {
+            const NAME: &str = $name;
+        }
+    };
+}
+
+impl_kind!(UFunc, 0, fns, "func");
+impl_kind!(UVar, 1, vars, "var");
+impl_kind!(UStruct, 2, structs, "struct");
+impl_kind!(UGeneric, 3, types, "type");
+impl_kind!(UData, 4, data, "data");
+pub const NAMED_KINDS: usize = 5;
+
 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 type VarID = ID<UVar>;
+pub type StructID = ID<UStruct>;
+pub type DataID = ID<UData>;
+pub type GenericID = ID<UGeneric>;
 
 pub trait Kind {
     const INDEX: usize;

src/ir/upper/program.rs

@@ -6,6 +6,7 @@ pub struct UProgram {
     pub fns: Vec<Option<UFunc>>,
     pub vars: Vec<Option<UVar>>,
     pub structs: Vec<Option<UStruct>>,
+    pub types: Vec<Option<UGeneric>>,
     pub data: Vec<Option<UData>>,
     pub start: Option<FnID>,
     pub names: NameMap,
@@ -46,6 +47,7 @@ impl UProgram {
             fns: Vec::new(),
             vars: Vec::new(),
             structs: Vec::new(),
+            types: Vec::new(),
             data: Vec::new(),
             start: None,
             names: NameMap::new(),
@@ -87,27 +89,6 @@ impl UProgram {
     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.structs[id.0]
-                .as_ref()?
-                .fields
-                .iter()
-                .try_fold(0, |sum, f| Some(sum + self.size_of_type(&f.ty)?))?,
-            Type::Fn { args, ret } => todo!(),
-            Type::Ref(_) => 64,
-            Type::Array(ty, len) => self.size_of_type(ty)? * len,
-            Type::Slice(_) => 128,
-            Type::Infer => return None,
-            Type::Error => return None,
-            Type::Unit => 0,
-        })
-    }
-    pub fn size_of_var(&self, var: VarID) -> Option<Size> {
-        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))
     }
@@ -145,6 +126,22 @@ impl UProgram {
         id
     }
 
+    pub fn field_type<'a>(&'a self, sty: &'a Type, field: &str) -> Option<&'a Type> {
+        let Type::Struct { id, args } = sty else {
+            return None;
+        };
+        let struc = self.get(*id)?;
+        let field = struc.fields.get(field)?;
+        if let Type::Generic { id } = field.ty {
+            for (i, g) in struc.generics.iter().enumerate() {
+                if *g == id {
+                    return Some(&args[i])
+                }
+            }
+        }
+        Some(&field.ty)
+    }
+
     pub fn type_name(&self, ty: &Type) -> String {
         let mut str = String::new();
         match ty {
@@ -176,10 +173,12 @@ impl UProgram {
             }
             Type::Error => str += "{error}",
             Type::Infer => str += "{inferred}",
+            Type::Generic { id } => str += self.names.get(*id),
             Type::Bits(size) => str += &format!("b{}", size),
             Type::Array(t, len) => str += &format!("[{}; {len}]", self.type_name(t)),
             Type::Unit => str += "()",
             Type::Slice(t) => str += &format!("&[{}]", self.type_name(t)),
+            Type::Placeholder => str += "{placeholder}",
         }
         str
     }
@@ -192,22 +191,6 @@ impl UProgram {
             last.insert(name, Idents::new(id.into()));
         }
     }
-    pub fn var_offset(&self, var: VarID) -> Option<VarOffset> {
-        let mut current = VarOffset { id: var, offset: 0 };
-        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_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()

src/ir/upper/ty.rs

@@ -1,15 +1,19 @@
-use super::{Len, StructID, UInstruction, UProgram, UVar, VarID};
+use std::collections::{HashMap, HashSet};
 
-#[derive(Clone, PartialEq)]
+use super::{GenericID, Len, StructID, UInstruction, UProgram, UVar, VarID};
+
+#[derive(Clone, PartialEq, Eq, Hash)]
 pub enum Type {
     Bits(u32),
     Struct { id: StructID, args: Vec<Type> },
+    Generic { id: GenericID },
     Fn { args: Vec<Type>, ret: Box<Type> },
     Ref(Box<Type>),
     Slice(Box<Type>),
     Array(Box<Type>, Len),
     Infer,
     Error,
+    Placeholder,
     Unit,
 }
 
@@ -23,81 +27,163 @@ impl Type {
     pub fn slice(self) -> Self {
         Self::Slice(Box::new(self))
     }
+    pub fn is_real(&self) -> bool {
+        !matches!(self, Self::Error | Self::Placeholder | Self::Infer)
+    }
 }
 
 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);
+        for (i, f) in self.iter_fns() {
+            let mut redo_iter = Vec::new();
+            let mut ph_vars = Vec::new();
+            let mut redo_new = Vec::new();
+            for i in f.flat_iter() {
+                if let Err(id) = self.resolve_instr_types(&mut vars, &i.i) {
+                    redo_iter.push(i);
+                    ph_vars.push(id);
+                }
+            }
+            while !redo_iter.is_empty() {
+                let mut new_ph = Vec::new();
+                for id in &ph_vars {
+                    let i = id.0;
+                    let Some(var) = &vars[i] else {
+                        continue;
+                    };
+                    if var.ty == Type::Placeholder
+                        && let Some(parent) = var.parent.as_ref()
+                    {
+                        let pty = &vars[parent.var.0].as_ref().unwrap().ty;
+                        if let Some(ft) = self.field_type(pty, &parent.field) {
+                            vars[i].as_mut().unwrap().ty = ft.clone();
+                        } else {
+                            new_ph.push(parent.var);
+                        }
+                    }
+                }
+                ph_vars = new_ph;
+                for &i in &redo_iter {
+                    if let Err(id) = self.resolve_instr_types(&mut vars, &i.i) {
+                        redo_new.push(i);
+                        ph_vars.push(id);
+                    }
+                }
+                std::mem::swap(&mut redo_iter, &mut redo_new);
+                redo_new.clear();
             }
         }
         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 = get(vars, dest.id);
-                let src_ty = get(vars, src.id);
-                if let Some(ty) = match_types(dest_ty, src_ty) {
-                    set(vars, dest.id, ty.clone());
-                    set(vars, src.id, ty);
+    pub fn resolve_instr_types(
+        &self,
+        vars: &mut Vec<Option<UVar>>,
+        i: &UInstruction,
+    ) -> Result<(), VarID> {
+        'outer: {
+            match &i {
+                UInstruction::Call { dest, f, args } => {
+                    let fun = self.get_fn_var(f.id).expect("bruh");
+                    vars[dest.id.0].as_mut().expect("bruh").ty = fun.ret.clone();
+                    for (src, &dest) in args.iter().zip(&fun.args) {
+                        let dest_ty = get(vars, dest)?;
+                        let src_ty = get(vars, src.id)?;
+                        if let Some(ty) = match_types(dest_ty, src_ty) {
+                            set(vars, dest, ty.clone());
+                            set(vars, src.id, ty);
+                        }
+                    }
                 }
-            }
-            UInstruction::Ref { dest, src } => {
-                let dest_ty = get(vars, dest.id);
-                let src_ty = get(vars, src.id);
-                if let Type::Ref(dest_ty) = dest_ty {
+                UInstruction::Mv { dest, src } => {
+                    let dest_ty = get(vars, dest.id)?;
+                    let src_ty = get(vars, src.id)?;
+                    if let Some(ty) = match_types(dest_ty, src_ty) {
+                        set(vars, dest.id, ty.clone());
+                        set(vars, src.id, ty);
+                    }
+                }
+                UInstruction::Ref { dest, src } => {
+                    let dest_ty = get(vars, dest.id)?;
+                    let src_ty = get(vars, src.id)?;
+                    let Type::Ref(dest_ty) = dest_ty else {
+                        break 'outer;
+                    };
                     if let Some(ty) = match_types(dest_ty, src_ty) {
                         set(vars, dest.id, ty.clone().rf());
                         set(vars, src.id, ty);
                     }
                 }
-            }
-            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::LoadData { dest, src } => {
+                    // TODO
                 }
-            }
-            UInstruction::Loop { body } => {
-                for i in body {
-                    self.resolve_instr_types(vars, &i.i);
+                UInstruction::LoadSlice { dest, src } => {
+                    // TODO
                 }
+                UInstruction::LoadFn { dest, src } => {
+                    // TODO
+                }
+                UInstruction::AsmBlock { instructions, args } => {
+                    // TODO
+                }
+                UInstruction::Ret { .. } => {}
+                UInstruction::Construct { dest, fields } => {
+                    let dest_ty = get(vars, dest.id)?;
+                    let Type::Struct { id, args } = dest_ty else {
+                        break 'outer;
+                    };
+                    let id = *id;
+                    let Some(struc) = self.get(id) else {
+                        break 'outer;
+                    };
+                    let mut new = HashMap::new();
+                    for (name, field) in &struc.fields {
+                        let Some(src) = fields.get(name) else {
+                            continue;
+                        };
+                        let src_ty = get(vars, src.id)?;
+                        if let Some(ty) = match_types(&field.ty, src_ty) {
+                            if let Type::Generic { id } = field.ty {
+                                new.insert(id, ty.clone());
+                            }
+                            set(vars, src.id, ty);
+                        }
+                    }
+                    let mut args: Vec<_> = struc
+                        .generics
+                        .iter()
+                        .map(|&id| Type::Generic { id })
+                        .collect();
+                    for (i, g) in struc.generics.iter().enumerate() {
+                        if let Some(ty) = new.remove(g) {
+                            args[i] = ty;
+                        }
+                    }
+                    // for arg in &args {
+                    //     println!("{:?}", self.type_name(arg));
+                    // }
+                    set(vars, dest.id, Type::Struct { id, args });
+                }
+                UInstruction::If { cond, body } => {}
+                UInstruction::Loop { body } => {}
+                UInstruction::Break => {}
+                UInstruction::Continue => {}
             }
-            UInstruction::Break => {}
-            UInstruction::Continue => {}
         }
+        Ok(())
     }
 }
 
-pub fn get(vars: &[Option<UVar>], id: VarID) -> &Type {
-    &vars[id.0]
+pub fn get(vars: &[Option<UVar>], id: VarID) -> Result<&Type, VarID> {
+    let var = vars[id.0]
         .as_ref()
-        .expect("PARTIAL BORROWING WOULD BE REALLY COOL")
-        .ty
+        .expect("PARTIAL BORROWING WOULD BE REALLY COOL");
+    if var.ty == Type::Placeholder {
+        return Err(id);
+    }
+    Ok(&var.ty)
 }
 
 pub fn set(vars: &mut [Option<UVar>], id: VarID, ty: Type) {
@@ -112,8 +198,11 @@ pub fn match_types(dest: &Type, src: &Type) -> Option<Type> {
         return None;
     }
     match (dest, src) {
-        (Type::Error, x) | (x, Type::Error) => None,
+        (Type::Error, _) | (_, Type::Error) => None,
+        (Type::Placeholder, _) | (_, Type::Placeholder) => None,
         (Type::Infer, x) | (x, Type::Infer) => Some(x.clone()),
+        // TODO: handle constraints?
+        (Type::Generic { id }, x) | (x, Type::Generic { id }) => Some(x.clone()),
         (
             Type::Struct {
                 id: dest_id,

src/ir/upper/validate.rs

@@ -21,6 +21,23 @@ impl UProgram {
                     spans: vec![var.origin],
                 });
             }
+            if var.ty == Type::Placeholder {
+                output.err(CompilerMsg {
+                    msg: format!("Var {:?} still placeholder!", id),
+                    spans: vec![var.origin],
+                });
+            }
+            if let Some(parent) = &var.parent {
+                let pty = &self.get(parent.var).unwrap().ty;
+                if let Some(ft) = self.field_type(pty, &parent.field) {
+                    output.check_assign(self, &var.ty, ft, var.origin);
+                } else {
+                    output.err(CompilerMsg {
+                        msg: format!("invalid parent!"),
+                        spans: vec![var.origin],
+                    });
+                }
+            }
         }
         output
     }
@@ -81,14 +98,15 @@ impl UProgram {
                 }
                 UInstruction::AsmBlock { instructions, args } => {
                     for arg in args {
-                        if let Some(size) = self.size_of_var(arg.var.id)
-                            && size != 64
-                        {
-                            output.err(CompilerMsg {
-                                msg: format!("asm block args must be size 64, is size {}", size),
-                                spans: vec![arg.var.span],
-                            });
-                        }
+                        // TODO: validate size with enabled targets
+                        // if let Some(size) = self.size_of_var(arg.var.id)
+                        //     && size != 64
+                        // {
+                        //     output.err(CompilerMsg {
+                        //         msg: format!("asm block args must be size 64, is size {}", size),
+                        //         spans: vec![arg.var.span],
+                        //     });
+                        // }
                     }
                 }
                 UInstruction::Ret { src } => {
@@ -98,24 +116,35 @@ impl UProgram {
                 }
                 UInstruction::Construct { dest, fields } => {
                     let dest_def = self.expect(dest.id);
-                    let tyid = match &dest_def.ty {
-                        Type::Struct { id, args } => *id,
+                    let (tyid, args) = match &dest_def.ty {
+                        Type::Struct { id, args } => (*id, args),
                         _ => {
                             output.err(CompilerMsg {
-                                msg: "uhh type is not struct".to_string(),
+                                msg: format!(
+                                    "Type {} cannot be constructed",
+                                    self.type_name(&dest_def.ty)
+                                ),
                                 spans: vec![dest.span],
                             });
                             continue;
                         }
                     };
                     let def = self.expect(tyid);
-                    for (id, field) in def.iter_fields() {
-                        if let Some(var) = fields.get(&id) {
+                    for (name, field) in &def.fields {
+                        if let Some(var) = fields.get(name) {
+                            let mut sty = &field.ty;
+                            if let Type::Generic { id } = sty {
+                                for (g, a) in def.generics.iter().zip(args) {
+                                    if *g == *id {
+                                        sty = a;
+                                    }
+                                }
+                            }
                             let ety = &self.expect(var.id).ty;
-                            output.check_assign(self, &field.ty, ety, var.span);
+                            output.check_assign(self, ety, sty, var.span);
                         } else {
                             output.err(CompilerMsg {
-                                msg: format!("field '{}' missing from struct", field.name),
+                                msg: format!("field '{}' missing from struct", name),
                                 spans: vec![dest.span],
                             });
                         }