diff --git a/src/frontend.rs b/src/frontend.rs
index 2b41f02..e7ee3d7 100644
--- a/src/frontend.rs
+++ b/src/frontend.rs
@@ -219,7 +219,9 @@ impl Context {
                         typ: self.types.primitives.infer,
                     }
                 }
-                BlockExpr::Block(block) => todo!(),
+                BlockExpr::Block(block) => {
+                    todo!("expression blocks not representable in typed ir yet")
+                }
             },
         };
         Ok(t_expr)
@@ -306,6 +308,7 @@ impl Context {
                 parser::ModuleItem::Comb(comb) => self.callable_from_block(comb)?,
                 parser::ModuleItem::Proc(_) => todo!("proc block"),
                 parser::ModuleItem::State(_) => todo!("state block"),
+                parser::ModuleItem::Struct(_) => todo!("struct block"),
             };
         }
         for item in module.items {
@@ -313,6 +316,7 @@ impl Context {
                 parser::ModuleItem::Comb(comb) => self.type_comb(comb)?,
                 parser::ModuleItem::Proc(_) => todo!("proc block"),
                 parser::ModuleItem::State(_) => todo!("state block"),
+                parser::ModuleItem::Struct(_) => todo!("struct block"),
             };
             typed_module.blocks.push(block);
         }
diff --git a/src/parser/adt.rs b/src/parser/adt.rs
index 518b820..3f2a888 100644
--- a/src/parser/adt.rs
+++ b/src/parser/adt.rs
@@ -1,3 +1,4 @@
+use super::declaration::{declaration, NetDecl};
 use super::tokens::{token, Token, TokenKind as tk, TokenSpan};
 use super::IResult;
 use nom::multi::separated_list0;
@@ -19,6 +20,12 @@ pub struct StateVariant<'a> {
     pub params: Option<Vec<Token<'a>>>,
 }
 
+#[derive(Debug)]
+pub struct StructBlock<'a> {
+    pub name: Token<'a>,
+    pub members: Vec<NetDecl<'a>>,
+}
+
 fn state_variant(input: TokenSpan) -> IResult<TokenSpan, StateVariant> {
     map(
         tuple((
@@ -52,3 +59,20 @@ pub fn state(input: TokenSpan) -> IResult<TokenSpan, StateBlock> {
         |(name, variants)| StateBlock { name, variants },
     )(input)
 }
+
+pub fn struct_def(input: TokenSpan) -> IResult<TokenSpan, StructBlock> {
+    map(
+        preceded(
+            token(tk::Struct),
+            cut(tuple((
+                token(tk::Ident),
+                delimited(
+                    token(tk::LBrace),
+                    separated_list0(token(tk::Comma), declaration),
+                    token(tk::RBrace),
+                ),
+            ))),
+        ),
+        |(name, members)| StructBlock { name, members },
+    )(input)
+}
diff --git a/src/parser/declaration.rs b/src/parser/declaration.rs
index f3dbc2b..fb4a014 100644
--- a/src/parser/declaration.rs
+++ b/src/parser/declaration.rs
@@ -32,7 +32,6 @@ pub struct TypeName<'a> {
 pub struct NetDecl<'a> {
     pub name: Span<'a>,
     pub typ: TypeName<'a>,
-    pub value: Option<Span<'a>>,
 }
 
 #[derive(Debug)]
@@ -54,14 +53,10 @@ pub fn assign_statement(input: TokenSpan) -> IResult<TokenSpan, Assign> {
 // TODO: reallow assignments
 pub fn declaration(i: TokenSpan) -> IResult<TokenSpan, NetDecl> {
     map(
-        tuple((
-            separated_pair(token(tk::Ident), token(tk::Colon), typename),
-            opt(preceded(token(tk::Assign), token(tk::Number))),
-        )),
-        |((ident, typ), _value)| NetDecl {
+        separated_pair(token(tk::Ident), token(tk::Colon), typename),
+        |(ident, typ)| NetDecl {
             name: ident.span(),
             typ,
-            value: None,
         },
     )(i)
 }
diff --git a/src/parser/module.rs b/src/parser/module.rs
index fb3aedb..34ab1a5 100644
--- a/src/parser/module.rs
+++ b/src/parser/module.rs
@@ -5,7 +5,7 @@ use nom::{
 };
 
 use crate::parser::{
-    adt::{state, StateBlock},
+    adt::{state, struct_def, StateBlock, StructBlock},
     comb::{comb_block, CombBlock},
     declaration,
     proc::ProcBlock,
@@ -35,6 +35,7 @@ pub enum ModuleItem<'a> {
     Comb(CombBlock<'a>),
     Proc(ProcBlock<'a>),
     State(StateBlock<'a>),
+    Struct(StructBlock<'a>),
 }
 
 fn port_decl(i: TokenSpan) -> IResult<TokenSpan, PortDecl> {
@@ -52,6 +53,7 @@ pub fn module(input: TokenSpan) -> IResult<TokenSpan, Module> {
     map(
         many1(alt((
             map(state, ModuleItem::State),
+            map(struct_def, ModuleItem::Struct),
             map(comb_block, ModuleItem::Comb),
         ))),
         |items| Module { items },
diff --git a/src/parser/tokens.rs b/src/parser/tokens.rs
index a3c23a6..2333153 100644
--- a/src/parser/tokens.rs
+++ b/src/parser/tokens.rs
@@ -87,6 +87,7 @@ pub enum TokenKind {
     Proc,
     Comb,
     Let,
+    Struct,
     // whitespace
     Comment,
     // Error
@@ -234,6 +235,7 @@ fn lex_keywords(input: Span) -> IResult<Span, Token> {
             map(tag("comb"), |_| TokenKind::Comb),
             map(tag("state"), |_| TokenKind::State),
             map(tag("let"), |_| TokenKind::Let),
+            map(tag("struct"), |_| TokenKind::Struct),
         ))),
         |(span, kind)| Token::new(span, kind),
     )(input)