diff --git a/crsn/src/asm/data/rd.rs b/crsn/src/asm/data/rd.rs
index 435c267..589bb62 100644
--- a/crsn/src/asm/data/rd.rs
+++ b/crsn/src/asm/data/rd.rs
@@ -1,4 +1,4 @@
-use std::fmt::{Debug, Formatter, Display};
+use std::fmt::{Debug, Display, Formatter};
 use std::fmt;
 
 use crate::asm::data::{DataDisp, Mask, RdData, Register};
diff --git a/crsn/src/asm/data/reg.rs b/crsn/src/asm/data/reg.rs
index b14c593..a43acba 100644
--- a/crsn/src/asm/data/reg.rs
+++ b/crsn/src/asm/data/reg.rs
@@ -1,7 +1,8 @@
 use std::fmt::{self, Display, Formatter};
 
-use crate::asm::error::CrsnError;
 use sexp::SourcePosition;
+
+use crate::asm::error::CrsnError;
 use crate::asm::patches::ErrWithPos;
 
 /// Register name
@@ -25,27 +26,27 @@ impl Display for Register {
     }
 }
 
-pub fn parse_reg(name: &str, at: SourcePosition) -> Result<Register, CrsnError> {
+pub fn parse_reg(name: &str, at: &SourcePosition) -> Result<Register, CrsnError> {
     // TODO deduplicate code
     if let Some(rn) = name.strip_prefix("arg") {
         if rn.chars().find(|c: &char| !c.is_ascii_digit()).is_some() {
-            return Err(CrsnError::Parse(format!("Bad register: {}", name).into(), at))?;
+            return Err(CrsnError::Parse(format!("Bad register: {}", name).into(), at.clone()))?;
         }
         let val: u8 = rn.parse().err_pos(at)?;
         Ok(Register::Arg(val))
     } else if let Some(rn) = name.strip_prefix("res") {
         if rn.chars().find(|c: &char| !c.is_ascii_digit()).is_some() {
-            return Err(CrsnError::Parse(format!("Bad register: {}", name).into(), at))?;
+            return Err(CrsnError::Parse(format!("Bad register: {}", name).into(), at.clone()))?;
         }
         let val: u8 = rn.parse().err_pos(at)?;
         Ok(Register::Res(val))
     } else if let Some(rn) = name.strip_prefix("r") {
         if rn.chars().find(|c: &char| !c.is_ascii_digit()).is_some() {
-            return Err(CrsnError::Parse(format!("Bad register: {}", name).into(), at))?;
+            return Err(CrsnError::Parse(format!("Bad register: {}", name).into(), at.clone()))?;
         }
         let val: u8 = rn.parse().err_pos(at)?;
         Ok(Register::Gen(val))
     } else {
-        Err(CrsnError::Parse(format!("Bad reg name: {}", name).into(), at))?
+        Err(CrsnError::Parse(format!("Bad reg name: {}", name).into(), at.clone()))?
     }
 }
diff --git a/crsn/src/asm/data/wr.rs b/crsn/src/asm/data/wr.rs
index 75509d6..8a7d8e8 100644
--- a/crsn/src/asm/data/wr.rs
+++ b/crsn/src/asm/data/wr.rs
@@ -1,4 +1,4 @@
-use std::fmt::{Debug, Formatter, Display};
+use std::fmt::{Debug, Display, Formatter};
 use std::fmt;
 
 use crate::asm::data::{DataDisp, Mask, Rd, WrData};
diff --git a/crsn/src/asm/error.rs b/crsn/src/asm/error.rs
index 12744a5..0f8bc49 100644
--- a/crsn/src/asm/error.rs
+++ b/crsn/src/asm/error.rs
@@ -1,13 +1,13 @@
 use std::borrow::Cow;
-use std::num::ParseIntError;
+use std::error::Error;
 
 use thiserror::Error;
 
+use sexp::SourcePosition;
+
 use crate::asm::data::{Mask, Register};
 use crate::asm::data::literal::Label;
 use crate::asm::instr::Cond;
-use sexp::SourcePosition;
-use std::error::Error;
 
 /// csn_asm unified error type
 #[derive(Error, Debug)]
diff --git a/crsn/src/asm/instr/cond.rs b/crsn/src/asm/instr/cond.rs
index e4f7774..4aa68ab 100644
--- a/crsn/src/asm/instr/cond.rs
+++ b/crsn/src/asm/instr/cond.rs
@@ -1,9 +1,10 @@
 use std::fmt::{self, Display, Formatter};
 use std::ops::Not;
 
-use crate::asm::error::CrsnError;
 use sexp::SourcePosition;
 
+use crate::asm::error::CrsnError;
+
 /// Condition flag
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
 pub enum Cond {
@@ -46,7 +47,7 @@ pub enum Cond {
     NotCarry,
 }
 
-pub fn parse_cond(text: &str, pos : SourcePosition) -> Result<Cond, CrsnError> {
+pub fn parse_cond(text: &str, pos: &SourcePosition) -> Result<Cond, CrsnError> {
     Ok(match text.trim_end_matches('?') {
         "eq" | "=" | "==" => Cond::Equal,
         "ne" | "<>" | "!=" | "≠" => Cond::NotEqual,
@@ -67,7 +68,7 @@ pub fn parse_cond(text: &str, pos : SourcePosition) -> Result<Cond, CrsnError> {
         "ov" | "^" => Cond::Overflow,
         "nov" | "!ov" | "!^" => Cond::NotOverflow,
         _ => {
-            return Err(CrsnError::Parse(format!("Unknown cond: {}", text).into(), pos));
+            return Err(CrsnError::Parse(format!("Unknown cond: {}", text).into(), pos.clone()));
         }
     })
 }
diff --git a/crsn/src/asm/instr/flatten.rs b/crsn/src/asm/instr/flatten.rs
index 95f1a27..07d03b7 100644
--- a/crsn/src/asm/instr/flatten.rs
+++ b/crsn/src/asm/instr/flatten.rs
@@ -1,5 +1,8 @@
 use std::collections::HashMap;
-use std::sync::atomic::{AtomicU32};
+use std::fmt::Debug;
+use std::sync::atomic::AtomicU32;
+
+use sexp::SourcePosition;
 
 use crate::asm::data::{Rd, RdData};
 use crate::asm::data::literal::{Label, Value};
@@ -8,11 +11,9 @@ use crate::asm::instr::{Cond, InstrWithBranches, Op, Routine};
 use crate::asm::instr::op::OpKind;
 use crate::builtin::defs::Barrier;
 use crate::builtin::defs::BuiltinOp;
-use std::fmt::Debug;
-use sexp::SourcePosition;
 
 /// A trait for something that can turn into multiple instructions
-pub trait Flatten : Debug {
+pub trait Flatten: Debug {
     fn flatten(self: Box<Self>, label_num: &AtomicU32) -> Result<Vec<Op>, CrsnError>;
 
     fn pos(&self) -> SourcePosition;
@@ -154,7 +155,7 @@ pub fn labels_to_skips(ops: Vec<Op>) -> Result<Vec<Op>, CrsnError> {
                     let skip = *dest as isize - n as isize + skipped;
                     cleaned.push(Op {
                         cond: op.cond,
-                        pos : op.pos.clone(),
+                        pos: op.pos.clone(),
                         kind: OpKind::BuiltIn(BuiltinOp::Skip(Rd::new(RdData::Immediate(skip as Value)))),
                     });
                 } else {
diff --git a/crsn/src/asm/instr/mod.rs b/crsn/src/asm/instr/mod.rs
index 28190e9..f71e181 100644
--- a/crsn/src/asm/instr/mod.rs
+++ b/crsn/src/asm/instr/mod.rs
@@ -1,9 +1,9 @@
 pub use cond::Cond;
 pub use flatten::Flatten;
 pub use op::Op;
+use sexp::SourcePosition;
 
 use crate::asm::data::literal::RoutineName;
-use sexp::SourcePosition;
 
 pub mod op;
 pub mod cond;
diff --git a/crsn/src/asm/instr/op.rs b/crsn/src/asm/instr/op.rs
index e432da4..9a96bc2 100644
--- a/crsn/src/asm/instr/op.rs
+++ b/crsn/src/asm/instr/op.rs
@@ -1,11 +1,12 @@
 use std::fmt::Debug;
 
+use sexp::{Atom, Sexp, SourcePosition};
+
 use crate::asm::instr::Cond;
 use crate::builtin::defs::BuiltinOp;
 use crate::module::{EvalRes, OpTrait};
 use crate::runtime::fault::Fault;
 use crate::runtime::run_thread::{info::ThreadInfo, state::RunState};
-use sexp::{Sexp, Atom, SourcePosition};
 
 /// A higher level simple opration
 #[derive(Debug)]
@@ -18,7 +19,7 @@ pub enum OpKind {
 #[derive(Debug)]
 pub struct Op {
     pub cond: Option<Cond>,
-    pub pos : SourcePosition,
+    pub pos: SourcePosition,
     pub kind: OpKind,
 }
 
diff --git a/crsn/src/asm/mod.rs b/crsn/src/asm/mod.rs
index 7217054..292713e 100644
--- a/crsn/src/asm/mod.rs
+++ b/crsn/src/asm/mod.rs
@@ -1,11 +1,12 @@
 use std::cell::RefCell;
 use std::sync::Arc;
 
+use sexp::SourcePosition;
+
+use crate::asm::instr::flatten::labels_to_skips;
 use crate::asm::parse::{ParserContext, ParserState};
 use crate::module::CrsnExtension;
 use crate::runtime::program::Program;
-use crate::asm::instr::flatten::labels_to_skips;
-use sexp::SourcePosition;
 
 pub mod data;
 pub mod error;
@@ -24,7 +25,7 @@ pub fn assemble(source: &str, parsers: Arc<Vec<Box<dyn CrsnExtension>>>) -> Resu
         }),
     };
 
-    let ops = parse::parse(source, SourcePosition::default(), &pcx)?;
+    let ops = parse::parse(source, &SourcePosition::default(), &pcx)?;
     let ops = labels_to_skips(ops)?;
 
     Ok(Program::new(ops, parsers)?)
diff --git a/crsn/src/asm/parse/arg_parser.rs b/crsn/src/asm/parse/arg_parser.rs
index 1bbfb7e..a5d911c 100644
--- a/crsn/src/asm/parse/arg_parser.rs
+++ b/crsn/src/asm/parse/arg_parser.rs
@@ -11,7 +11,7 @@ use crate::asm::patches::NextOrErr;
 pub struct TokenParser<'a> {
     orig_len: usize,
     args: Vec<Sexp>,
-    start_pos: SourcePosition,
+    start_pos: &'a SourcePosition,
     pub pcx: &'a ParserContext<'a>,
 }
 
@@ -29,7 +29,7 @@ impl<'a> IntoIterator for TokenParser<'a> {
 
 impl<'a> TokenParser<'a> {
     /// Create a new argument parser
-    pub fn new(mut args: Vec<Sexp>, start_pos: SourcePosition, pcx: &'a ParserContext) -> Self {
+    pub fn new(mut args: Vec<Sexp>, start_pos: &'a SourcePosition, pcx: &'a ParserContext) -> Self {
         args.reverse();
         Self {
             orig_len: args.len(),
diff --git a/crsn/src/asm/parse/mod.rs b/crsn/src/asm/parse/mod.rs
index cf87193..bcfbbd0 100644
--- a/crsn/src/asm/parse/mod.rs
+++ b/crsn/src/asm/parse/mod.rs
@@ -3,6 +3,7 @@ use std::collections::HashMap;
 use std::sync::atomic::AtomicU32;
 
 pub use parse_instr::parse_instructions;
+use sexp::SourcePosition;
 
 use crate::asm::data::literal::{ConstantName, RegisterAlias, Value};
 use crate::asm::data::Register;
@@ -10,7 +11,6 @@ use crate::asm::error::CrsnError;
 use crate::asm::instr::Op;
 use crate::asm::parse::sexp_expect::expect_list;
 use crate::module::CrsnExtension;
-use sexp::SourcePosition;
 
 pub mod parse_cond;
 pub mod parse_instr;
@@ -39,7 +39,7 @@ pub struct ParserState {
     pub constants: HashMap<ConstantName, Value>,
 }
 
-pub fn parse(source: &str, pos: SourcePosition, parsers: &ParserContext) -> Result<Vec<Op>, CrsnError> {
+pub fn parse(source: &str, pos: &SourcePosition, parsers: &ParserContext) -> Result<Vec<Op>, CrsnError> {
     let (items, _pos) = expect_list(sexp::parse(source)?, true)?;
 
     /* numbered labels start with a weird high number
diff --git a/crsn/src/asm/parse/parse_cond.rs b/crsn/src/asm/parse/parse_cond.rs
index bbbeb9e..0205b17 100644
--- a/crsn/src/asm/parse/parse_cond.rs
+++ b/crsn/src/asm/parse/parse_cond.rs
@@ -9,12 +9,12 @@ use crate::asm::patches::TryRemove;
 
 pub fn parse_cond_branch(tok: Sexp, parsers: &ParserContext) -> Result<(Cond, Box<dyn Flatten>), CrsnError> {
     let (mut list, pos) = expect_list(tok, false)?;
-    let (kw, kw_pos) = expect_string_atom(list.remove_or_err(0, pos.clone(), "Missing \"cond?\" keyword in conditional branch")?)?;
+    let (kw, kw_pos) = expect_string_atom(list.remove_or_err(0, &pos, "Missing \"cond?\" keyword in conditional branch")?)?;
 
     if !kw.ends_with('?') {
         return Err(CrsnError::Parse(format!("Condition must end with '?': {}", kw).into(), kw_pos));
     }
 
-    Ok((cond::parse_cond(&kw, kw_pos)?, parse_instructions(list.into_iter(), pos, parsers)?))
+    Ok((cond::parse_cond(&kw, &kw_pos)?, parse_instructions(list.into_iter(), &pos, parsers)?))
 }
 
diff --git a/crsn/src/asm/parse/parse_data.rs b/crsn/src/asm/parse/parse_data.rs
index 436fc31..bc0e6d4 100644
--- a/crsn/src/asm/parse/parse_data.rs
+++ b/crsn/src/asm/parse/parse_data.rs
@@ -8,7 +8,6 @@ use crate::asm::data::literal::{ConstantName, Label, RegisterAlias, Value};
 use crate::asm::error::CrsnError;
 use crate::asm::parse::ParserContext;
 use crate::asm::parse::sexp_expect::expect_string_atom;
-use std::num::TryFromIntError;
 use crate::asm::patches::ErrWithPos;
 
 fn is_valid_identifier(name: &str) -> bool {
@@ -46,14 +45,14 @@ pub fn parse_constant_name(name: Sexp) -> Result<(ConstantName, SourcePosition),
 pub fn parse_label(name: Sexp) -> Result<Label, CrsnError> {
     // trace!("parse label: {:?}", name);
     let (name, namepos) = expect_string_atom(name)?;
-    Ok(parse_label_str(&name, namepos)?)
+    Ok(parse_label_str(&name, &namepos)?)
 }
 
-pub fn parse_label_str(name: &str, pos: SourcePosition) -> Result<Label, CrsnError> {
+pub fn parse_label_str(name: &str, pos: &SourcePosition) -> Result<Label, CrsnError> {
     let label = name.trim_start_matches(':');
 
     Ok(if label.starts_with('#') {
-        let val = parse_u64(&label[1..], pos.clone())?;
+        let val = parse_u64(&label[1..], pos)?;
         Label::Numbered(u32::try_from(val).err_pos(pos)?)
     } else {
         Label::Named(label.to_string())
@@ -67,7 +66,7 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
     // TODO implement masks
 
     match tok {
-        Sexp::Atom(Atom::I(val), pos) => {
+        Sexp::Atom(Atom::I(val), _pos) => {
             Ok(DataDisp::Immediate(unsafe { std::mem::transmute(val) }))
         }
         Sexp::Atom(Atom::S(s), pos) => {
@@ -92,7 +91,7 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
                 if let Some(val) = pstate.reg_aliases.get(reference) {
                     Ok(DataDisp::ObjectPtr(*val))
                 } else {
-                    let reg = reg::parse_reg(reference, pos.clone())?;
+                    let reg = reg::parse_reg(reference, &pos)?;
 
                     if pstate.reg_aliases.values().find(|v| **v == reg).is_some() {
                         Err(CrsnError::Parse(format!("Sym exists for register {}, direct access denied. Unsym it if needed.", reg).into(), pos))
@@ -101,9 +100,9 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
                     }
                 }
             } else if s.starts_with(|c: char| c.is_ascii_digit()) {
-                Ok(DataDisp::Immediate(unsafe { std::mem::transmute(parse_i64(&s, pos)?) }))
+                Ok(DataDisp::Immediate(unsafe { std::mem::transmute(parse_i64(&s, &pos)?) }))
             } else {
-                let reg = reg::parse_reg(&s, pos.clone())?;
+                let reg = reg::parse_reg(&s, &pos)?;
 
                 let pstate = pcx.state.borrow();
                 if pstate.reg_aliases.values().find(|v| **v == reg).is_some() {
@@ -122,7 +121,7 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
 /// Parse immediate value
 pub fn parse_value(tok: Sexp, pcx: &ParserContext) -> Result<Value, CrsnError> {
     match tok {
-        Sexp::Atom(Atom::I(val), pos) => {
+        Sexp::Atom(Atom::I(val), _pos) => {
             Ok(unsafe { std::mem::transmute(val) })
         }
         Sexp::Atom(Atom::S(s), pos) => {
@@ -131,7 +130,7 @@ pub fn parse_value(tok: Sexp, pcx: &ParserContext) -> Result<Value, CrsnError> {
                 return Ok(*val);
             }
 
-            Ok(unsafe { std::mem::transmute(parse_i64(&s, pos)?) })
+            Ok(unsafe { std::mem::transmute(parse_i64(&s, &pos)?) })
         }
         other => {
             Err(CrsnError::Parse(format!("bad value format: {:?}", other).into(), other.pos().clone()))
@@ -140,7 +139,7 @@ pub fn parse_value(tok: Sexp, pcx: &ParserContext) -> Result<Value, CrsnError> {
 }
 
 
-pub fn parse_u64(literal: &str, pos: SourcePosition) -> Result<u64, CrsnError> {
+pub fn parse_u64(literal: &str, pos: &SourcePosition) -> Result<u64, CrsnError> {
     // trace!("parse u64 from {}", literal);
     let mut without_underscores = Cow::Borrowed(literal);
     if without_underscores.contains('_') {
@@ -156,21 +155,21 @@ pub fn parse_u64(literal: &str, pos: SourcePosition) -> Result<u64, CrsnError> {
     }
 }
 
-pub fn parse_i64(literal: &str, pos: SourcePosition) -> Result<i64, CrsnError> {
+pub fn parse_i64(literal: &str, pos: &SourcePosition) -> Result<i64, CrsnError> {
     // trace!("parse i64 from {}", literal);
     if let Some(_value) = literal.strip_prefix("-") {
-        Ok(-1 * i64::try_from(parse_u64(literal, pos.clone())?).err_pos(pos)?)
+        Ok(-1 * i64::try_from(parse_u64(literal, pos)?).err_pos(pos)?)
     } else {
-        Ok(i64::try_from(parse_u64(literal, pos.clone())?).err_pos(pos)?)
+        Ok(i64::try_from(parse_u64(literal, pos)?).err_pos(pos)?)
     }
 }
 
 pub fn parse_rd(tok: Sexp, pcx: &ParserContext) -> Result<Rd, CrsnError> {
     let pos = tok.pos().clone();
-    Ok(Rd::new(RdData::try_from(parse_data_disp(tok, pcx)?).err_pos(pos)?))
+    Ok(Rd::new(RdData::try_from(parse_data_disp(tok, pcx)?).err_pos(&pos)?))
 }
 
 pub fn parse_wr(tok: Sexp, pcx: &ParserContext) -> Result<Wr, CrsnError> {
     let pos = tok.pos().clone();
-    Ok(Wr::new(WrData::try_from(parse_data_disp(tok, pcx)?).err_pos(pos)?))
+    Ok(Wr::new(WrData::try_from(parse_data_disp(tok, pcx)?).err_pos(&pos)?))
 }
diff --git a/crsn/src/asm/parse/parse_instr.rs b/crsn/src/asm/parse/parse_instr.rs
index 7b78183..8f24234 100644
--- a/crsn/src/asm/parse/parse_instr.rs
+++ b/crsn/src/asm/parse/parse_instr.rs
@@ -7,12 +7,12 @@ use crate::asm::parse::parse_cond::parse_cond_branch;
 use crate::asm::parse::parse_routine::parse_routine;
 use crate::asm::parse::ParserContext;
 use crate::asm::parse::sexp_expect::{expect_list, expect_string_atom};
+use crate::asm::patches::NextOrErr;
 use crate::module::ParseRes;
 
 use super::parse_op::parse_op;
-use crate::asm::patches::NextOrErr;
 
-pub fn parse_instructions(items: impl Iterator<Item=Sexp>, pos: SourcePosition, pcx: &ParserContext) -> Result<Box<dyn Flatten>, CrsnError> {
+pub fn parse_instructions(items: impl Iterator<Item=Sexp>, pos: &SourcePosition, pcx: &ParserContext) -> Result<Box<dyn Flatten>, CrsnError> {
     let mut parsed = vec![];
     for expr in items {
         let (tokens, listpos) = expect_list(expr, false)?;
@@ -21,13 +21,13 @@ pub fn parse_instructions(items: impl Iterator<Item=Sexp>, pos: SourcePosition,
         let (name, namepos) = expect_string_atom(toki.next_or_err(listpos.clone(), "Expected instruction name token")?)?;
 
         if name == "proc" {
-            parsed.push(parse_routine(toki, pos.clone(), pcx)?);
+            parsed.push(parse_routine(toki, pos, pcx)?);
             continue;
         }
 
-        let mut token_parser = TokenParser::new(toki.collect(), listpos.clone(), pcx);
+        let mut token_parser = TokenParser::new(toki.collect(), &listpos, pcx);
         for p in pcx.parsers {
-            token_parser = match p.parse_syntax(pos.clone(), &name, token_parser) {
+            token_parser = match p.parse_syntax(pos, &name, token_parser) {
                 Ok(ParseRes::Parsed(op)) => return Ok(op),
                 Ok(ParseRes::ParsedNone) => return Ok(Box::new(())),
                 Ok(ParseRes::Unknown(to_reuse)) => {
@@ -45,7 +45,7 @@ pub fn parse_instructions(items: impl Iterator<Item=Sexp>, pos: SourcePosition,
         // Get back the original iterator
         let toki = token_parser.into_iter();
 
-        let arg_tokens = TokenParser::new(toki.clone().take_while(|e| e.is_atom()).collect(), listpos.clone(), pcx);
+        let arg_tokens = TokenParser::new(toki.clone().take_while(|e| e.is_atom()).collect(), &listpos, pcx);
         let branch_tokens = toki
             .skip_while(|e| e.is_atom())
             .take_while(|e| e.is_list());
@@ -62,7 +62,7 @@ pub fn parse_instructions(items: impl Iterator<Item=Sexp>, pos: SourcePosition,
             }
         };
 
-        if let Some(op) = parse_op(name.as_str(), arg_tokens, namepos.clone())? {
+        if let Some(op) = parse_op(name.as_str(), arg_tokens, &namepos)? {
             parsed.push(Box::new(InstrWithBranches {
                 op,
                 pos: namepos,
diff --git a/crsn/src/asm/parse/parse_op.rs b/crsn/src/asm/parse/parse_op.rs
index 1ceb58c..bf26826 100644
--- a/crsn/src/asm/parse/parse_op.rs
+++ b/crsn/src/asm/parse/parse_op.rs
@@ -1,32 +1,33 @@
+use sexp::SourcePosition;
+
 use crate::asm::error::CrsnError;
 use crate::asm::instr::cond::parse_cond;
 use crate::asm::instr::Op;
 use crate::asm::parse::arg_parser::TokenParser;
-use crate::module::ParseRes;
 use crate::builtin::BuiltinOps;
-use sexp::SourcePosition;
+use crate::module::ParseRes;
 
-pub fn parse_op<'a>(mut keyword: &str, mut arg_tokens: TokenParser<'a>, spos: SourcePosition) -> Result<Option<Op>, CrsnError> {
+pub fn parse_op<'a>(mut keyword: &str, mut arg_tokens: TokenParser<'a>, spos: &SourcePosition) -> Result<Option<Op>, CrsnError> {
     // Include built-in instructions
     let builtins = [BuiltinOps::new()];
     let mut cond = None;
 
     if let Some(pos) = keyword.find('.') {
-        cond = Some(parse_cond(&keyword[(pos + 1)..], spos.clone())?);
+        cond = Some(parse_cond(&keyword[(pos + 1)..], spos)?);
         keyword = &keyword[..pos];
     }
 
     for p in builtins.iter().chain(arg_tokens.pcx.parsers) {
-        arg_tokens = match p.parse_op(spos.clone(), keyword, arg_tokens) {
+        arg_tokens = match p.parse_op(spos, keyword, arg_tokens) {
             Ok(ParseRes::Parsed(kind)) => return Ok(Some(Op {
                 cond,
-                pos: spos,
+                pos: spos.clone(),
                 kind,
             })),
             Ok(ParseRes::ParsedNone) => return Ok(None),
             Ok(ParseRes::Unknown(to_reuse)) => {
                 if to_reuse.parsing_started() {
-                    return Err(CrsnError::Parse(format!("Module \"{}\" started parsing {}, but returned Unknown!", p.name(), keyword).into(), spos));
+                    return Err(CrsnError::Parse(format!("Module \"{}\" started parsing {}, but returned Unknown!", p.name(), keyword).into(), spos.clone()));
                 }
                 to_reuse
             }
@@ -36,5 +37,5 @@ pub fn parse_op<'a>(mut keyword: &str, mut arg_tokens: TokenParser<'a>, spos: So
         }
     }
 
-    return Err(CrsnError::Parse(format!("Unknown instruction: {}", keyword).into(), spos));
+    return Err(CrsnError::Parse(format!("Unknown instruction: {}", keyword).into(), spos.clone()));
 }
diff --git a/crsn/src/asm/parse/parse_routine.rs b/crsn/src/asm/parse/parse_routine.rs
index 34819aa..e849cff 100644
--- a/crsn/src/asm/parse/parse_routine.rs
+++ b/crsn/src/asm/parse/parse_routine.rs
@@ -7,14 +7,14 @@ use crate::asm::parse::{parse_instructions, ParserContext};
 use crate::asm::parse::arg_parser::TokenParser;
 use crate::asm::parse::parse_data::parse_reg_alias;
 use crate::asm::parse::sexp_expect::expect_string_atom;
-use crate::builtin::parse::parse_routine_name;
 use crate::asm::patches::NextOrErr;
+use crate::builtin::parse::parse_routine_name;
 
-pub fn parse_routine(mut toki: impl Iterator<Item=Sexp> + Clone, rt_pos: SourcePosition, pcx: &ParserContext) -> Result<Box<dyn Flatten>, CrsnError> {
+pub fn parse_routine(mut toki: impl Iterator<Item=Sexp> + Clone, rt_pos: &SourcePosition, pcx: &ParserContext) -> Result<Box<dyn Flatten>, CrsnError> {
     let (name, namepos) = expect_string_atom(toki.next_or_err(rt_pos.clone(), "Expected routine name")?)?;
-    let mut name = parse_routine_name(name, namepos)?;
+    let mut name = parse_routine_name(name, &namepos)?;
 
-    let arg_tokens = TokenParser::new(toki.clone().take_while(|e| e.is_atom()).collect(), rt_pos.clone(), pcx);
+    let arg_tokens = TokenParser::new(toki.clone().take_while(|e| e.is_atom()).collect(), rt_pos, pcx);
 
     // If arity is explicitly given, then either no named argument must be provided,
     // or their count must match the arity. If no arity is given, then arity is determined
@@ -22,7 +22,7 @@ pub fn parse_routine(mut toki: impl Iterator<Item=Sexp> + Clone, rt_pos: SourceP
     if name.arity == 0 && arg_tokens.len() != 0 {
         name.arity = arg_tokens.len() as u8;
     } else if arg_tokens.len() != 0 && name.arity as usize != arg_tokens.len() {
-        return Err(CrsnError::Parse(format!("arity mismatch in routine {}", name.name).into(), rt_pos));
+        return Err(CrsnError::Parse(format!("arity mismatch in routine {}", name.name).into(), rt_pos.clone()));
     }
 
     let toki = toki.skip_while(|e| e.is_atom());
@@ -44,7 +44,7 @@ pub fn parse_routine(mut toki: impl Iterator<Item=Sexp> + Clone, rt_pos: SourceP
         }
     }
 
-    let body = parse_instructions(toki, rt_pos.clone(), pcx)?;
+    let body = parse_instructions(toki, rt_pos, pcx)?;
 
     {
         let mut pstate = pcx.state.borrow_mut();
@@ -54,7 +54,7 @@ pub fn parse_routine(mut toki: impl Iterator<Item=Sexp> + Clone, rt_pos: SourceP
 
     return Ok(Box::new(Routine {
         name,
-        pos: rt_pos,
+        pos: rt_pos.clone(),
         body,
     }));
 }
diff --git a/crsn/src/asm/patches/mod.rs b/crsn/src/asm/patches/mod.rs
index aa299b5..b36202c 100644
--- a/crsn/src/asm/patches/mod.rs
+++ b/crsn/src/asm/patches/mod.rs
@@ -1,12 +1,12 @@
 use sexp::SourcePosition;
+
 use crate::asm::error::CrsnError;
-use std::borrow::Cow;
 
 pub trait TryRemove {
     type Item;
     fn try_remove(&mut self, index: usize) -> Option<Self::Item>;
 
-    fn remove_or_err(&mut self, index: usize, pos: SourcePosition, err : &'static str) -> Result<Self::Item, CrsnError>;
+    fn remove_or_err(&mut self, index: usize, pos: &SourcePosition, err: &'static str) -> Result<Self::Item, CrsnError>;
 }
 
 impl<T> TryRemove for Vec<T> {
@@ -20,10 +20,10 @@ impl<T> TryRemove for Vec<T> {
         }
     }
 
-    fn remove_or_err(&mut self, index: usize, pos: SourcePosition, err : &'static str) -> Result<Self::Item, CrsnError> {
+    fn remove_or_err(&mut self, index: usize, pos: &SourcePosition, err: &'static str) -> Result<Self::Item, CrsnError> {
         match self.try_remove(index) {
             None => {
-                Err(CrsnError::Parse(err.into(), pos))
+                Err(CrsnError::Parse(err.into(), pos.clone()))
             }
             Some(removed) => Ok(removed)
         }
@@ -31,10 +31,10 @@ impl<T> TryRemove for Vec<T> {
 }
 
 pub trait NextOrErr<T> {
-    fn next_or_err(&mut self, pos: SourcePosition, err : &'static str) -> Result<T, CrsnError>;
+    fn next_or_err(&mut self, pos: SourcePosition, err: &'static str) -> Result<T, CrsnError>;
 }
 
-impl<T, K : Iterator<Item=T>> NextOrErr<T> for K {
+impl<T, K: Iterator<Item=T>> NextOrErr<T> for K {
     fn next_or_err(&mut self, pos: SourcePosition, err: &'static str) -> Result<T, CrsnError> {
         match self.next() {
             None => {
@@ -46,14 +46,14 @@ impl<T, K : Iterator<Item=T>> NextOrErr<T> for K {
 }
 
 pub trait ErrWithPos<T> {
-    fn err_pos(self, pos : SourcePosition) -> Result<T, CrsnError>;
+    fn err_pos(self, pos: &SourcePosition) -> Result<T, CrsnError>;
 }
 
-impl<T, E : std::error::Error + Send + Sync + 'static> ErrWithPos<T> for Result<T, E> {
-    fn err_pos(self, pos : SourcePosition) -> Result<T, CrsnError> {
+impl<T, E: std::error::Error + Send + Sync + 'static> ErrWithPos<T> for Result<T, E> {
+    fn err_pos(self, pos: &SourcePosition) -> Result<T, CrsnError> {
         match self {
             Ok(v) => Ok(v),
-            Err(e) => Err(CrsnError::ParseOther(Box::new(e), pos))
+            Err(e) => Err(CrsnError::ParseOther(Box::new(e), pos.clone()))
         }
     }
 }
diff --git a/crsn/src/builtin/defs.rs b/crsn/src/builtin/defs.rs
index 686f432..db3de9d 100644
--- a/crsn/src/builtin/defs.rs
+++ b/crsn/src/builtin/defs.rs
@@ -1,8 +1,9 @@
+use sexp::SourcePosition;
+
 use crate::asm::data::{Rd, RdObj, Wr};
 use crate::asm::data::literal::{DebugMsg, Label, RoutineName};
 use crate::asm::instr::Op;
 use crate::asm::instr::op::OpKind;
-use sexp::SourcePosition;
 
 #[derive(Debug)]
 pub enum Barrier {
diff --git a/crsn/src/builtin/exec.rs b/crsn/src/builtin/exec.rs
index 7574c6a..45a0db5 100644
--- a/crsn/src/builtin/exec.rs
+++ b/crsn/src/builtin/exec.rs
@@ -1,5 +1,7 @@
 use std::time::Duration;
 
+use sexp::Sexp;
+
 use crate::asm::data::{Rd, RdData};
 use crate::asm::data::literal::Addr;
 use crate::asm::instr::Cond;
@@ -8,11 +10,6 @@ use crate::module::{EvalRes, OpTrait};
 use crate::runtime::fault::Fault;
 use crate::runtime::frame::StackFrame;
 use crate::runtime::run_thread::{state::RunState, ThreadInfo};
-use sexp::Sexp;
-
-
-
-
 
 impl OpTrait for BuiltinOp {
     fn execute(&self, info: &ThreadInfo, state: &mut RunState) -> Result<EvalRes, Fault> {
diff --git a/crsn/src/builtin/mod.rs b/crsn/src/builtin/mod.rs
index 0fa9a9f..fdf1ea9 100644
--- a/crsn/src/builtin/mod.rs
+++ b/crsn/src/builtin/mod.rs
@@ -1,9 +1,10 @@
-use crate::module::{CrsnExtension, ParseRes};
-use crate::asm::parse::arg_parser::TokenParser;
-use crate::asm::instr::op::OpKind;
-use crate::asm::error::CrsnError;
 use sexp::SourcePosition;
 
+use crate::asm::error::CrsnError;
+use crate::asm::instr::op::OpKind;
+use crate::asm::parse::arg_parser::TokenParser;
+use crate::module::{CrsnExtension, ParseRes};
+
 pub mod defs;
 pub mod exec;
 pub mod parse;
@@ -22,7 +23,7 @@ impl CrsnExtension for BuiltinOps {
         "builtin"
     }
 
-    fn parse_op<'a>(&self, pos: SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+    fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
         parse::parse_op(pos, keyword, args)
     }
 }
diff --git a/crsn/src/builtin/parse.rs b/crsn/src/builtin/parse.rs
index 873fd90..ec5a57f 100644
--- a/crsn/src/builtin/parse.rs
+++ b/crsn/src/builtin/parse.rs
@@ -5,15 +5,14 @@ use crate::asm::data::reg::parse_reg;
 use crate::asm::error::CrsnError;
 use crate::asm::instr::op::OpKind;
 use crate::asm::parse::arg_parser::TokenParser;
-use crate::asm::parse::parse_data::{parse_constant_name, parse_label, parse_rd, parse_reg_alias, parse_value, parse_label_str};
+use crate::asm::parse::parse_data::{parse_constant_name, parse_label, parse_label_str, parse_rd, parse_reg_alias, parse_value};
 use crate::asm::parse::sexp_expect::expect_string_atom;
+use crate::asm::patches::ErrWithPos;
 use crate::builtin::defs::{Barrier, BuiltinOp};
-use crate::module::{ParseRes};
+use crate::module::ParseRes;
 use crate::utils::A;
-use crate::asm::patches::ErrWithPos;
-
 
-pub(crate) fn parse_op<'a>(op_pos: SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+pub(crate) fn parse_op<'a>(op_pos: &SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
     let pcx = args.pcx;
 
     Ok(ParseRes::Parsed(OpKind::BuiltIn(match keyword {
@@ -35,7 +34,7 @@ pub(crate) fn parse_op<'a>(op_pos: SourcePosition, keyword: &str, mut args: Toke
             let (alias, aliaspos) = parse_reg_alias(args.next_or_err()?)?;
             trace!("alias={:?}", alias);
             let (rn, rpos) = args.next_string()?;
-            let register = parse_reg(&rn, rpos.clone())?;
+            let register = parse_reg(&rn, &rpos)?;
             trace!("register={:?}", alias);
 
             let mut pstate = pcx.state.borrow_mut();
@@ -124,7 +123,7 @@ pub(crate) fn parse_op<'a>(op_pos: SourcePosition, keyword: &str, mut args: Toke
 
         "routine" => {
             let name = args.next_string()?;
-            BuiltinOp::Routine(parse_routine_name(name.0, name.1)?)
+            BuiltinOp::Routine(parse_routine_name(name.0, &name.1)?)
         }
 
         "skip" => {
@@ -200,7 +199,7 @@ pub(crate) fn parse_op<'a>(op_pos: SourcePosition, keyword: &str, mut args: Toke
 
         other => {
             if let Some(label) = other.strip_prefix(':') {
-                BuiltinOp::Label(parse_label_str(label, op_pos)?)
+                BuiltinOp::Label(parse_label_str(label, &op_pos)?)
             } else {
                 return Ok(ParseRes::Unknown(args));
             }
@@ -208,7 +207,7 @@ pub(crate) fn parse_op<'a>(op_pos: SourcePosition, keyword: &str, mut args: Toke
     })))
 }
 
-pub(crate) fn parse_routine_name(name: String, pos: SourcePosition) -> Result<RoutineName, CrsnError> {
+pub(crate) fn parse_routine_name(name: String, pos: &SourcePosition) -> Result<RoutineName, CrsnError> {
     let (name, arity) = if let Some(n) = name.find('/') {
         (
             (&name[0..n]).to_string(),
@@ -238,7 +237,7 @@ pub(crate) fn to_sexp(op: &BuiltinOp) -> Sexp {
                 inner.extend(args.iter().map(A));
                 sexp::list(&inner)
             }
-        },
+        }
         BuiltinOp::Ret(values) => {
             if values.is_empty() {
                 sexp::list(&[A("ret")])
@@ -287,16 +286,15 @@ pub(crate) fn to_sexp(op: &BuiltinOp) -> Sexp {
 
 #[cfg(test)]
 mod test {
-    
-    
     use std::sync::atomic::AtomicU32;
 
-    use crate::asm::instr::{Flatten};
+    use sexp::SourcePosition;
+
+    use crate::asm::instr::Flatten;
     use crate::asm::parse::{parse_instructions, ParserContext};
     use crate::asm::parse::sexp_expect::expect_list;
-    
-    use crate::module::OpTrait;
     use crate::builtin::BuiltinOps;
+    use crate::module::OpTrait;
 
     #[test]
     fn roundtrip() {
@@ -306,10 +304,10 @@ mod test {
             ("(nop)", "(nop)"),
             ("(halt)", "(halt)"),
             ("(sleep 1000)", "(sleep 1000)"),
-            ("(:x)\
-              (j :x)", "(skip 0)"),
-            ("(:#7)\
-              (j :#7)", "(skip 0)"),
+            ("(:x)", "(:x)"),
+            ("(j :x)", "(j :x)"),
+            ("(:#7)", "(:#7)"),
+            ("(j :#7)", "(j :#7)"),
             ("(fj :x)", "(fj :x)"),
             ("(skip 0)", "(skip 0)"),
             ("(skip r0)", "(skip r0)"),
@@ -367,9 +365,9 @@ mod test {
             /* first cycle */
             let s = sexp::parse(&format!("({})", sample))
                 .expect("parse sexp");
-            let list = expect_list(Some(s), false).unwrap();
+            let list = expect_list(s, false).unwrap();
             let num = AtomicU32::new(0);
-            let parsed = parse_instructions(list.into_iter(), &pcx)
+            let parsed = parse_instructions(list.0.into_iter(), &SourcePosition::default(), &pcx)
                 .expect("parse instr").flatten(&num)
                 .expect("flatten").remove(0);
 
@@ -379,13 +377,17 @@ mod test {
             assert_eq!(expected, exported);
 
             println!(" - 2nd cycle");
+            let pcx = ParserContext {
+                parsers,
+                state: Default::default(),
+            };
 
             /* second cycle, nothing should change */
             let s = sexp::parse(&format!("({})", exported))
                 .expect("parse sexp (2c)");
-            let list = expect_list(Some(s), false).unwrap();
+            let list = expect_list(s, false).unwrap();
             let num = AtomicU32::new(0);
-            let parsed = parse_instructions(list.into_iter(), &pcx)
+            let parsed = parse_instructions(list.0.into_iter(), &SourcePosition::default(), &pcx)
                 .expect("parse instr (2c)").flatten(&num)
                 .expect("flatten (2c)").remove(0);
 
diff --git a/crsn/src/module/mod.rs b/crsn/src/module/mod.rs
index 77ff1ac..2861ace 100644
--- a/crsn/src/module/mod.rs
+++ b/crsn/src/module/mod.rs
@@ -1,8 +1,9 @@
 #![allow(unused_variables)]
 
-use std::fmt::{Debug};
+use std::fmt::Debug;
 
 pub use eval_res::EvalRes;
+use sexp::{Sexp, SourcePosition};
 
 use crate::asm::data::literal::Value;
 use crate::asm::data::Mask;
@@ -13,8 +14,6 @@ use crate::asm::parse::arg_parser::TokenParser;
 use crate::runtime::fault::Fault;
 use crate::runtime::run_thread::state::RunState;
 use crate::runtime::run_thread::ThreadInfo;
-use sexp::{Sexp, SourcePosition};
-
 
 mod eval_res;
 
@@ -53,12 +52,12 @@ pub trait CrsnExtension: Debug + Send + Sync + 'static {
     /// If the instruction keyword is not recognized, return Unknown with the unchanged argument list.
     ///
     /// pcx is available on the arg_tokens parser
-    fn parse_op<'a>(&self, pos: SourcePosition, keyword: &str, arg_tokens: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError>;
+    fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, arg_tokens: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError>;
 
     /// Parse a generic S-expression (non-op)
     ///
     /// pcx is available on the arg_tokens parser
-    fn parse_syntax<'a>(&self, pos: SourcePosition, keyword: &str, tokens: TokenParser<'a>)
+    fn parse_syntax<'a>(&self, pos: &SourcePosition, keyword: &str, tokens: TokenParser<'a>)
                         -> Result<ParseRes<'a, Box<dyn Flatten>>, CrsnError>
     {
         Ok(ParseRes::Unknown(tokens))
diff --git a/crsn/src/runtime/program.rs b/crsn/src/runtime/program.rs
index 279e43e..1ddebdc 100644
--- a/crsn/src/runtime/program.rs
+++ b/crsn/src/runtime/program.rs
@@ -1,14 +1,15 @@
 use std::collections::HashMap;
 use std::sync::Arc;
 
+use sexp::SourcePosition;
+
 use crate::asm::data::literal::{Addr, Label, RoutineName};
+use crate::asm::error::CrsnError;
 use crate::asm::instr::Op;
 use crate::asm::instr::op::OpKind;
 use crate::builtin::defs::{Barrier, BuiltinOp};
 use crate::module::CrsnExtension;
 use crate::runtime::fault::Fault;
-use sexp::SourcePosition;
-use crate::asm::error::CrsnError;
 
 #[derive(Debug)]
 pub struct Program {
@@ -96,9 +97,9 @@ impl Program {
                 pos: SourcePosition {
                     line: 0,
                     column: 0,
-                    index: 0
+                    index: 0,
                 },
-                cond: None
+                cond: None,
             }
         } else {
             &self.ops[addr.0 as usize]
diff --git a/crsn/src/utils/mod.rs b/crsn/src/utils/mod.rs
index 7a365ce..052b9a0 100644
--- a/crsn/src/utils/mod.rs
+++ b/crsn/src/utils/mod.rs
@@ -1,8 +1,9 @@
-pub use option_ext::UncheckedOptionExt;
 use std::fmt::Display;
-use sexp::{Sexp, Atom};
 use std::str::FromStr;
 
+pub use option_ext::UncheckedOptionExt;
+use sexp::{Atom, Sexp};
+
 mod option_ext;
 
 /// Convert a string token to Sexp
diff --git a/crsn_arith/src/exec.rs b/crsn_arith/src/exec.rs
index 7118d91..412473a 100644
--- a/crsn_arith/src/exec.rs
+++ b/crsn_arith/src/exec.rs
@@ -2,16 +2,16 @@ use std::ops::Rem;
 
 use num_traits::PrimInt;
 
+use crsn::asm::data::{Rd, Wr};
 use crsn::asm::instr::Cond;
 use crsn::module::{EvalRes, OpTrait};
 use crsn::runtime::fault::Fault;
 use crsn::runtime::run_thread::{state::RunState, ThreadInfo};
-
-use crate::defs::ArithOp;
-use crsn::sexp::Sexp;
 use crsn::sexp;
+use crsn::sexp::Sexp;
 use crsn::utils::A;
-use crsn::asm::data::{Rd, Wr};
+
+use crate::defs::ArithOp;
 
 impl OpTrait for ArithOp {
     fn execute(&self, _ti: &ThreadInfo, state: &mut RunState) -> Result<EvalRes, Fault> {
@@ -238,7 +238,7 @@ impl OpTrait for ArithOp {
     }
 }
 
-fn to_sexp_2_or_3(name: &str, dst : &Wr, a: &Rd, b: &Rd) -> Sexp {
+fn to_sexp_2_or_3(name: &str, dst: &Wr, a: &Rd, b: &Rd) -> Sexp {
     if &dst.as_rd() == a {
         sexp::list(&[A(name), A(dst), A(b)])
     } else {
diff --git a/crsn_arith/src/lib.rs b/crsn_arith/src/lib.rs
index ba06694..146fb98 100644
--- a/crsn_arith/src/lib.rs
+++ b/crsn_arith/src/lib.rs
@@ -22,7 +22,7 @@ impl CrsnExtension for ArithOps {
         "arith"
     }
 
-    fn parse_op<'a>(&self, pos: SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+    fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
         parse::parse(pos, keyword, args)
     }
 }
diff --git a/crsn_arith/src/parse.rs b/crsn_arith/src/parse.rs
index 4248a11..e4a7fb0 100644
--- a/crsn_arith/src/parse.rs
+++ b/crsn_arith/src/parse.rs
@@ -3,11 +3,11 @@ use crsn::asm::error::CrsnError;
 use crsn::asm::instr::op::OpKind;
 use crsn::asm::parse::arg_parser::TokenParser;
 use crsn::module::ParseRes;
+use crsn::sexp::SourcePosition;
 
 use crate::defs::ArithOp;
-use crsn::sexp::SourcePosition;
 
-pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+pub(crate) fn parse<'a>(pos: &SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
     Ok(ParseRes::ext(match keyword {
         "cmp" => {
             ArithOp::Compare {
@@ -57,7 +57,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Add requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Add requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -80,7 +80,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Sub requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Sub requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -103,7 +103,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Mul requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Mul requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -130,7 +130,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("DivR requires 3 or 4 arguments".into(), pos));
+                    return Err(CrsnError::Parse("DivR requires 3 or 4 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -156,7 +156,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Div requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Div requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -180,7 +180,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Mod requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Mod requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -203,7 +203,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("And requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("And requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -226,7 +226,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Or requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Or requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -249,7 +249,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Xor requires 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Xor requires 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -270,7 +270,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Cpl requires 1 or 2 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Cpl requires 1 or 2 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -301,7 +301,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Rol requires 1, 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Rol requires 1, 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -332,7 +332,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Ror requires 1, 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Ror requires 1, 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -363,7 +363,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Lsl requires 1, 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Lsl requires 1, 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -394,7 +394,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Lsr requires 1, 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Lsr requires 1, 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
@@ -425,7 +425,7 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
                     }
                 }
                 _ => {
-                    return Err(CrsnError::Parse("Asr requires 1, 2 or 3 arguments".into(), pos));
+                    return Err(CrsnError::Parse("Asr requires 1, 2 or 3 arguments".into(), pos.clone()));
                 }
             }
         }
diff --git a/crsn_screen/src/exec.rs b/crsn_screen/src/exec.rs
index 1afd177..63bac12 100644
--- a/crsn_screen/src/exec.rs
+++ b/crsn_screen/src/exec.rs
@@ -1,19 +1,19 @@
 use std::ops::Sub;
 use std::time::{Duration, Instant};
 
-use minifb::{ScaleMode, Window, WindowOptions, MouseMode, Key, MouseButton};
+use minifb::{Key, MouseButton, MouseMode, ScaleMode, Window, WindowOptions};
 
 use crsn::asm::data::literal::Value;
 use crsn::asm::instr::Cond;
 use crsn::module::{EvalRes, OpTrait};
 use crsn::runtime::fault::Fault;
 use crsn::runtime::run_thread::{state::RunState, ThreadInfo};
-
-use crate::defs::ScreenOp;
-use crsn::sexp::Sexp;
 use crsn::sexp;
+use crsn::sexp::Sexp;
 use crsn::utils::A;
 
+use crate::defs::ScreenOp;
+
 #[derive(Debug)]
 struct Opts {
     auto_blit: bool,
@@ -299,7 +299,7 @@ fn blit(backend: &mut Backend) {
     backend.last_render = Instant::now();
 }
 
-fn num2key(num : Value) -> Option<Key> {
+fn num2key(num: Value) -> Option<Key> {
     let remap = [
         Key::Key0,
         Key::Key1,
@@ -311,7 +311,6 @@ fn num2key(num : Value) -> Option<Key> {
         Key::Key7,
         Key::Key8,
         Key::Key9,
-
         Key::A, // 10
         Key::B,
         Key::C,
@@ -361,7 +360,6 @@ fn num2key(num : Value) -> Option<Key> {
         Key::Up,
         Key::Apostrophe,
         Key::Backquote,
-
         Key::Backslash, // 57
         Key::Comma,
         Key::Equal,
@@ -370,20 +368,17 @@ fn num2key(num : Value) -> Option<Key> {
         Key::Period,
         Key::RightBracket,
         Key::Semicolon,
-
         Key::Slash, // 65
         Key::Backspace,
         Key::Delete,
         Key::End,
         Key::Enter,
-
         Key::Escape, // 70
         Key::Home,
         Key::Insert,
         Key::Menu,
         Key::PageDown,
         Key::PageUp,
-
         Key::Pause, // 76
         Key::Space,
         Key::Tab,
@@ -394,7 +389,6 @@ fn num2key(num : Value) -> Option<Key> {
         Key::RightShift,
         Key::LeftCtrl,
         Key::RightCtrl,
-
         Key::NumPad0, // 86
         Key::NumPad1,
         Key::NumPad2,
diff --git a/crsn_screen/src/lib.rs b/crsn_screen/src/lib.rs
index 9b569f5..f4f8c3c 100644
--- a/crsn_screen/src/lib.rs
+++ b/crsn_screen/src/lib.rs
@@ -25,7 +25,7 @@ impl CrsnExtension for ScreenOps {
         "screen"
     }
 
-    fn parse_op<'a>(&self, pos: SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+    fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
         parse::parse(pos, keyword, args)
     }
 }
diff --git a/crsn_screen/src/parse.rs b/crsn_screen/src/parse.rs
index f73c20b..8ccbb7e 100644
--- a/crsn_screen/src/parse.rs
+++ b/crsn_screen/src/parse.rs
@@ -1,13 +1,13 @@
-use crsn::asm::data::{Rd};
+use crsn::asm::data::Rd;
 use crsn::asm::error::CrsnError;
 use crsn::asm::instr::op::OpKind;
 use crsn::asm::parse::arg_parser::TokenParser;
 use crsn::module::ParseRes;
+use crsn::sexp::SourcePosition;
 
 use crate::defs::ScreenOp;
-use crsn::sexp::SourcePosition;
 
-pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+pub(crate) fn parse<'a>(_pos: &SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
     Ok(ParseRes::ext(match keyword {
         "sc-init" => {
             ScreenOp::ScreenInit {
@@ -65,14 +65,14 @@ pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParse
         "sc-key" => {
             ScreenOp::TestKey {
                 pressed: args.next_wr()?,
-                code: args.next_rd()?
+                code: args.next_rd()?,
             }
         }
 
         "sc-mbtn" => {
             ScreenOp::TestMouse {
                 pressed: args.next_wr()?,
-                button: args.next_rd()?
+                button: args.next_rd()?,
             }
         }
 
diff --git a/crsn_stacks/src/exec.rs b/crsn_stacks/src/exec.rs
index 2a6cdc9..f11554f 100644
--- a/crsn_stacks/src/exec.rs
+++ b/crsn_stacks/src/exec.rs
@@ -1,16 +1,16 @@
 use std::collections::{HashMap, VecDeque};
 
+use crsn::asm::data::{Rd, RdObj, Wr};
 use crsn::asm::data::literal::Value;
 use crsn::asm::instr::Cond;
 use crsn::module::{EvalRes, OpTrait};
 use crsn::runtime::fault::Fault;
 use crsn::runtime::run_thread::{state::RunState, ThreadInfo};
-
-use crate::defs::StackOp;
-use crsn::sexp::Sexp;
 use crsn::sexp;
+use crsn::sexp::Sexp;
 use crsn::utils::A;
-use crsn::asm::data::{RdObj, Rd, Wr};
+
+use crate::defs::StackOp;
 
 #[derive(Debug, Default)]
 struct Stacks {
@@ -66,7 +66,7 @@ pub(crate) fn drop_obj(state: &mut RunState, handle: Value) -> Result<Option<()>
     Ok(stacks.store.remove(&handle).map(|_| ()))
 }
 
-fn prepare_push(state: &mut RunState, obj: &RdObj, src: &Rd, pushfn : impl FnOnce(&mut VecDeque<Value>, Value) -> ()) -> Result<(), Fault> {
+fn prepare_push(state: &mut RunState, obj: &RdObj, src: &Rd, pushfn: impl FnOnce(&mut VecDeque<Value>, Value) -> ()) -> Result<(), Fault> {
     state.clear_status();
     let handle = state.read_obj(*obj)?;
     let val = state.read(*src)?;
@@ -79,7 +79,7 @@ fn prepare_push(state: &mut RunState, obj: &RdObj, src: &Rd, pushfn : impl FnOnc
     Ok(())
 }
 
-fn prepare_pop(state: &mut RunState, dst: &Wr, obj: &RdObj, popfn : impl FnOnce(&mut VecDeque<Value>) -> Option<Value>) -> Result<(), Fault> {
+fn prepare_pop(state: &mut RunState, dst: &Wr, obj: &RdObj, popfn: impl FnOnce(&mut VecDeque<Value>) -> Option<Value>) -> Result<(), Fault> {
     state.clear_status();
     let handle = state.read_obj(*obj)?;
 
diff --git a/crsn_stacks/src/lib.rs b/crsn_stacks/src/lib.rs
index 6059f4e..424a813 100644
--- a/crsn_stacks/src/lib.rs
+++ b/crsn_stacks/src/lib.rs
@@ -25,7 +25,7 @@ impl CrsnExtension for StackOps {
         "stacks"
     }
 
-    fn parse_op<'a>(&self, pos: SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+    fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
         parse::parse(pos, keyword, args)
     }
 
diff --git a/crsn_stacks/src/parse.rs b/crsn_stacks/src/parse.rs
index 0458180..5fb3199 100644
--- a/crsn_stacks/src/parse.rs
+++ b/crsn_stacks/src/parse.rs
@@ -2,11 +2,11 @@ use crsn::asm::error::CrsnError;
 use crsn::asm::instr::op::OpKind;
 use crsn::asm::parse::arg_parser::TokenParser;
 use crsn::module::ParseRes;
+use crsn::sexp::SourcePosition;
 
 use crate::defs::StackOp;
-use crsn::sexp::SourcePosition;
 
-pub(crate) fn parse<'a>(pos: SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
+pub(crate) fn parse<'a>(_pos: &SourcePosition, keyword: &str, mut args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
     Ok(ParseRes::ext(match keyword {
         "stack" => {
             StackOp::NewStack {
diff --git a/launcher/src/main.rs b/launcher/src/main.rs
index 95e0965..748c0f5 100644
--- a/launcher/src/main.rs
+++ b/launcher/src/main.rs
@@ -10,11 +10,11 @@ use clappconfig::clap::ArgMatches;
 use serde::{Deserialize, Serialize};
 
 use crsn::asm::data::literal::Addr;
+use crsn::module::OpTrait;
 use crsn::runtime::run_thread::{RunThread, ThreadToken};
 use crsn_arith::ArithOps;
 use crsn_screen::ScreenOps;
 use crsn_stacks::StackOps;
-use crsn::module::OpTrait;
 
 mod read_file;
 mod serde_duration_millis;
diff --git a/lib/spanned_sexp/.travis.yml b/lib/spanned_sexp/.travis.yml
index a4430b7..9a98210 100644
--- a/lib/spanned_sexp/.travis.yml
+++ b/lib/spanned_sexp/.travis.yml
@@ -8,9 +8,9 @@ addons:
       - libelf-dev
       - libdw-dev
 rust:
-- nightly
+  - nightly
 os:
-- linux
+  - linux
 
 env:
   global:
@@ -21,16 +21,16 @@ before_script:
   - pip install 'travis-cargo<0.2' --user && export PATH=$HOME/.local/bin:$PATH
 
 script:
-- travis-cargo build
-- travis-cargo test
-- travis-cargo bench
-- travis-cargo doc
+  - travis-cargo build
+  - travis-cargo test
+  - travis-cargo bench
+  - travis-cargo doc
 after_success:
-- |
-  [ $TRAVIS_BRANCH = master ] &&
-  [ $TRAVIS_PULL_REQUEST = false ] &&
-  echo '<meta http-equiv=refresh content=0;url=sexp/index.html>' > target/doc/index.html &&
-  git clone --depth 1 https://github.com/davisp/ghp-import &&
-  ./ghp-import/ghp-import -n target/doc &&
-  git push -fq https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git gh-pages
-- travis-cargo coveralls --no-sudo
+  - |
+    [ $TRAVIS_BRANCH = master ] &&
+    [ $TRAVIS_PULL_REQUEST = false ] &&
+    echo '<meta http-equiv=refresh content=0;url=sexp/index.html>' > target/doc/index.html &&
+    git clone --depth 1 https://github.com/davisp/ghp-import &&
+    ./ghp-import/ghp-import -n target/doc &&
+    git push -fq https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git gh-pages
+  - travis-cargo coveralls --no-sudo
diff --git a/lib/spanned_sexp/Cargo.toml b/lib/spanned_sexp/Cargo.toml
index 4742a78..7ba146a 100644
--- a/lib/spanned_sexp/Cargo.toml
+++ b/lib/spanned_sexp/Cargo.toml
@@ -4,12 +4,12 @@ version = "1.1.4"
 authors = ["Clark Gaebel <cg.wowus.cg@gmail.com>"]
 
 documentation = "https://cgaebel.github.io/sexp"
-homepage      = "https://github.com/cgaebel/sexp"
-repository    = "https://github.com/cgaebel/sexp"
+homepage = "https://github.com/cgaebel/sexp"
+repository = "https://github.com/cgaebel/sexp"
 
 readme = "README.md"
 
-keywords = [ "sexp", "parsing", "s-expression", "file-format" ]
+keywords = ["sexp", "parsing", "s-expression", "file-format"]
 
 description = "A small, simple, self-contained, s-expression parser and pretty-printer."
 
diff --git a/lib/spanned_sexp/src/error.rs b/lib/spanned_sexp/src/error.rs
index 34ab7aa..1807365 100644
--- a/lib/spanned_sexp/src/error.rs
+++ b/lib/spanned_sexp/src/error.rs
@@ -12,11 +12,11 @@ pub struct Error {
 #[derive(Debug, PartialEq, Clone, Default)]
 pub struct SourcePosition {
     /// The line number on which the error occurred.
-    pub line: usize,
+    pub line: u32,
     /// The column number on which the error occurred.
-    pub column: usize,
+    pub column: u32,
     /// The index in the given string which caused the error.
-    pub index: usize,
+    pub index: u32,
 }
 
 /// Since errors are the uncommon case, they're boxed. This keeps the size of
@@ -56,9 +56,9 @@ pub(crate) fn get_line_and_column(s: &str, pos: usize) -> SourcePosition {
         }
     }
     SourcePosition {
-        line,
-        column: cmp::max(col, 0) as usize,
-        index: pos,
+        line: line as u32,
+        column: cmp::max(col, 0) as u32,
+        index: pos as u32,
     }
 }
 
@@ -66,7 +66,7 @@ pub(crate) fn get_line_and_column(s: &str, pos: usize) -> SourcePosition {
 fn err_impl(message: &'static str, s: &str, pos: &usize) -> Err {
     Box::new(Error {
         message,
-        pos: get_line_and_column(s, *pos)
+        pos: get_line_and_column(s, *pos),
     })
 }
 
diff --git a/lib/spanned_sexp/src/lib.rs b/lib/spanned_sexp/src/lib.rs
index ee0ba18..bbbaa9c 100644
--- a/lib/spanned_sexp/src/lib.rs
+++ b/lib/spanned_sexp/src/lib.rs
@@ -11,9 +11,9 @@ use std::borrow::Cow;
 use std::fmt;
 use std::str::{self, FromStr};
 
+use error::{ERes, err, spos};
 pub use error::Error;
 pub use error::SourcePosition;
-use error::{ERes, err, spos};
 
 #[cfg(test)]
 mod test;
diff --git a/lib/spanned_sexp/src/test.rs b/lib/spanned_sexp/src/test.rs
index f96beca..f32f2ce 100644
--- a/lib/spanned_sexp/src/test.rs
+++ b/lib/spanned_sexp/src/test.rs
@@ -27,8 +27,8 @@ fn test_pp() {
 fn test_tight_parens() {
     let s = "(hello(world))";
     let sexp = parse(s).unwrap();
-    assert_eq!(sexp, Sexp::List(vec![Sexp::Atom(Atom::S("hello".into()), None),
-                                     Sexp::List(vec![Sexp::Atom(Atom::S("world".into()), None)], None)], None));
+    assert_eq!(sexp, Sexp::List(vec![Sexp::Atom(Atom::S("hello".into()), Default::default()),
+                                     Sexp::List(vec![Sexp::Atom(Atom::S("world".into()), Default::default())], Default::default())], Default::default()));
     let s = "(this (has)tight(parens))";
     let s2 = "( this ( has ) tight ( parens ) )";
     assert_eq!(parse(s).unwrap(), parse(s2).unwrap());
@@ -66,5 +66,5 @@ fn line_and_col_test() {
 fn sexp_size() {
     // I just want to see when this changes, in the diff.
     use std::mem;
-    assert_eq!(mem::size_of::<Sexp>(), mem::size_of::<isize>() * 5);
+    assert_eq!(mem::size_of::<Sexp>(), mem::size_of::<isize>() * 6);
 }