diff --git a/src/literals.rs b/src/literals.rs
index 1bfafb9..bfa6967 100644
--- a/src/literals.rs
+++ b/src/literals.rs
@@ -8,20 +8,9 @@ use nom::{
     AsChar, FindToken, InputIter, InputLength, Offset, Slice
 };
 
-use crate::parser::IResult;
+use crate::parser::{IResult, Span};
 
-pub fn hexadecimal<'a, I>(input: I) -> IResult<I, u64>
-where
-    // TODO: ask if there is any way to avoid this hellish constraint
-    I: InputIter
-        + nom::Slice<RangeFrom<usize>>
-        + InputLength
-        + Clone
-        + Offset
-        + Into<&'a str>
-        + Slice<RangeTo<usize>>,
-    <I as InputIter>::Item: AsChar + Copy,
-    &'a str: FindToken<<I as InputIter>::Item>
+pub fn hexadecimal(input: Span) -> IResult<Span, u64>
 {
     map_res(
         preceded(
@@ -31,7 +20,7 @@ where
                 many0(char('_')),
             ))),
         ),
-        |out: I| u64::from_str_radix(&str::replace(&out.into(), "_", ""), 16),
+        |out: Span| u64::from_str_radix(&str::replace(&out.fragment(), "_", ""), 16),
     )(input)
 }
 
@@ -41,7 +30,7 @@ mod test {
 
     #[test]
     fn test_hex() {
-        assert_eq!(hexadecimal("hfF").unwrap().1, 0xff);
-        assert_eq!(hexadecimal("hF").unwrap().1, 0xf);
+        assert_eq!(hexadecimal("hfF".into()).unwrap().1, 0xff);
+        assert_eq!(hexadecimal("hF".into()).unwrap().1, 0xf);
     }
 }
diff --git a/src/main.rs b/src/main.rs
index d5051a9..d62d640 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -24,10 +24,12 @@ fn main() {
         .read_to_string(&mut input)
         .expect("error reading file");
     let input: &str = input.as_str();
-    let parsed = parser::parse(&input);
+    let input = parser::Span::new(input);
+    let parsed = parser::parse(input);
     match parsed {
         Err(nom::Err::Error(err) | nom::Err::Failure(err)) => {
-            print!("{}", convert_error(input, err))
+            // TODO: get this working again
+            // print!("{}", convert_error(input, err))
         }
         Err(_) => (),
         Ok(res) => {
diff --git a/src/parser.rs b/src/parser.rs
index e172098..87ff8b7 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -2,7 +2,7 @@ use nom::{
     branch::alt,
     bytes::complete::tag,
     character::complete::{alpha1, alphanumeric1, char, multispace0, multispace1, u64 as decimal},
-    combinator::{map, opt, recognize},
+    combinator::{map, opt, recognize, consumed},
     error::{context, ParseError, VerboseError},
     multi::{many0, many1, separated_list0},
     sequence::{delimited, pair, preceded, separated_pair, terminated, tuple},
@@ -11,33 +11,34 @@ use nom::{
 use nom_locate::{position, LocatedSpan};
 
 // custom span type for nom_locate
-type Span<'a> = LocatedSpan<&'a str>;
+pub type Span<'a> = LocatedSpan<&'a str>;
 
 // custom IResult type for VerboseError
 pub type IResult<I, O, E = VerboseError<I>> = nom::IResult<I, O, E>;
 
 use crate::literals::hexadecimal;
 
-fn ws0<'a, F: 'a, O, E: ParseError<&'a str>>(
+fn ws0<'a, F: 'a, O, E: ParseError<Span<'a>>>(
     inner: F,
-) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
+) -> impl FnMut(Span<'a>) -> IResult<Span<'a>, O, E>
 where
-    F: FnMut(&'a str) -> IResult<&'a str, O, E>,
+    F: FnMut(Span<'a>) -> IResult<Span<'a>, O, E>,
 {
     delimited(multispace0, inner, multispace0)
 }
-fn identifier(input: &str) -> IResult<&str, &str> {
+
+fn identifier(input: Span) -> IResult<Span, Span> {
     recognize(pair(
         alt((alpha1, tag("_"))),
         many0(alt((alphanumeric1, tag("_")))),
     ))(input)
 }
 
-fn widthspec(input: &str) -> IResult<&str, u64> {
+fn widthspec(input: Span) -> IResult<Span, u64> {
     delimited(char('['), ws0(decimal), char(']'))(input)
 }
 
-fn intliteral(input: &str) -> IResult<&str, (u64, u64)> {
+fn intliteral(input: Span) -> IResult<Span, (u64, u64)> {
     tuple((terminated(decimal, char('\'')), alt((decimal, hexadecimal))))(input)
 }
 
@@ -55,15 +56,16 @@ pub enum PortDirection {
 }
 
 #[derive(Debug)]
-pub struct PortDecl {
+pub struct PortDecl<'a> {
+    pub pos: Span<'a>,
     pub direction: PortDirection,
     pub net: NetDecl,
 }
 
 #[derive(Debug)]
-pub struct Module {
+pub struct Module<'a> {
     pub name: String,
-    pub ports: Vec<PortDecl>,
+    pub ports: Vec<PortDecl<'a>>,
     pub statements: Vec<Statement>,
 }
 
@@ -97,7 +99,7 @@ pub enum Expression {
     Operation(Box<Operation>),
 }
 
-fn declaration(i: &str) -> IResult<&str, NetDecl> {
+fn declaration(i: Span) -> IResult<Span, NetDecl> {
     map(
         tuple((
             ws0(alt((tag("reg"), tag("wire")))),
@@ -106,45 +108,47 @@ fn declaration(i: &str) -> IResult<&str, NetDecl> {
             opt(preceded(ws0(char('=')), intliteral)),
         )),
         |(_, width, ident, value)| NetDecl {
-            name: ident.into(),
+            name: (*ident.fragment()).into(),
             width,
             value,
         },
     )(i)
 }
 
-fn port_decl(i: &str) -> IResult<&str, PortDecl> {
+fn port_decl(i: Span) -> IResult<Span, PortDecl> {
     map(
-        tuple((
-            alt((
-                map(tag("input"), |_| PortDirection::Input),
-                map(tag("output"), |_| PortDirection::Output),
-            )),
-            declaration,
-        )),
-        |(direction, net)| PortDecl { direction, net },
+        consumed(
+            tuple((
+                alt((
+                    map(tag("input"), |_| PortDirection::Input),
+                    map(tag("output"), |_| PortDirection::Output),
+                )),
+                declaration,
+            ))
+        ),
+        |(pos, (direction, net))| PortDecl { pos, direction, net },
     )(i)
 }
 
-fn ports_list(input: &str) -> IResult<&str, Vec<PortDecl>> {
+fn ports_list(input: Span) -> IResult<Span, Vec<PortDecl>> {
     separated_list0(ws0(char(',')), ws0(port_decl))(input)
 }
 
-fn operation(input: &str) -> IResult<&str, Operation> {
+fn operation(input: Span) -> IResult<Span, Operation> {
     // temporarily given up on before I learn the shunting yard algorithm
     alt((
         map(
             separated_pair(ws0(identifier), char('&'), ws0(expression)),
-            |(a, b)| Operation::And { a: a.into(), b },
+            |(a, b)| Operation::And { a: (*a.fragment()).into(), b },
         ),
         map(
             separated_pair(ws0(identifier), char('|'), ws0(expression)),
-            |(a, b)| Operation::Or { a: a.into(), b },
+            |(a, b)| Operation::Or { a: (*a.fragment()).into(), b },
         ),
     ))(input)
 }
 
-fn call_item(input: &str) -> IResult<&str, Call> {
+fn call_item(input: Span) -> IResult<Span, Call> {
     map(
         tuple((
             ws0(identifier),
@@ -155,21 +159,21 @@ fn call_item(input: &str) -> IResult<&str, Call> {
             ),
         )),
         |(name, args)| Call {
-            name: name.into(),
+            name: (*name.fragment()).into(),
             args,
         },
     )(input)
 }
 
-fn expression(input: &str) -> IResult<&str, Expression> {
+fn expression(input: Span) -> IResult<Span, Expression> {
     alt((
         map(ws0(operation), |op| Expression::Operation(Box::new(op))),
         map(ws0(call_item), |call| Expression::Call(Box::new(call))),
-        map(ws0(identifier), |ident| Expression::Ident(ident.into())),
+        map(ws0(identifier), |ident| Expression::Ident((*ident.fragment()).into())),
     ))(input)
 }
 
-fn assign_statement(input: &str) -> IResult<&str, Statement> {
+fn assign_statement(input: Span) -> IResult<Span, Statement> {
     context(
         "assignment",
         delimited(
@@ -178,8 +182,8 @@ fn assign_statement(input: &str) -> IResult<&str, Statement> {
                 separated_pair(ws0(identifier), char('='), ws0(expression)),
                 |(lhs, expr)| {
                     Statement::Assign(Assign {
-                        lhs: lhs.into(),
-                        expr: expr.into(),
+                        lhs: (*lhs.fragment()).into(),
+                        expr,
                     })
                 },
             ),
@@ -188,7 +192,7 @@ fn assign_statement(input: &str) -> IResult<&str, Statement> {
     )(input)
 }
 
-pub fn module(input: &str) -> IResult<&str, Module> {
+pub fn module(input: Span) -> IResult<Span, Module> {
     context(
         "module",
         map(
@@ -203,7 +207,7 @@ pub fn module(input: &str) -> IResult<&str, Module> {
                 )),
             )),
             |(_, name, ports, statements)| Module {
-                name: name.into(),
+                name: (*name.fragment()).into(),
                 ports,
                 statements,
             },
@@ -211,7 +215,7 @@ pub fn module(input: &str) -> IResult<&str, Module> {
     )(input)
 }
 
-pub fn parse(input: &str) -> IResult<&str, Module> {
+pub fn parse(input: Span) -> IResult<Span, Module> {
     module(input)
 }
 
@@ -221,32 +225,32 @@ mod test {
 
     #[test]
     fn test_decl() {
-        declaration("reg abcd").unwrap();
+        declaration("reg abcd".into()).unwrap();
     }
 
     #[test]
     fn test_operation() {
-        operation(" a | b ").unwrap();
-        operation(" a & b ").unwrap();
+        operation(" a | b ".into()).unwrap();
+        operation(" a & b ".into()).unwrap();
     }
 
     #[test]
     fn test_expression() {
-        expression(" a ").unwrap();
-        expression(" a | b ").unwrap();
-        expression(" a | b | c ").unwrap();
+        expression(" a ".into()).unwrap();
+        expression(" a | b ".into()).unwrap();
+        expression(" a | b | c ".into()).unwrap();
     }
 
     #[test]
     fn test_assignment() {
-        assign_statement(" assign a = b ; ").unwrap();
-        assign_statement(" assign a = b | c ; ").unwrap();
+        assign_statement(" assign a = b ; ".into()).unwrap();
+        assign_statement(" assign a = b | c ; ".into()).unwrap();
     }
 
     #[test]
     fn test_call() {
-        call_item("thing ( )").unwrap();
-        call_item("thing ( a , b , c )").unwrap();
-        call_item("thing(a,b,c)").unwrap();
+        call_item("thing ( )".into()).unwrap();
+        call_item("thing ( a , b , c )".into()).unwrap();
+        call_item("thing(a,b,c)".into()).unwrap();
     }
 }