diff --git a/src/compiler.rs b/src/compiler.rs
index fc227a5..3c96842 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -3,7 +3,7 @@ use std::{collections::HashMap, str::FromStr};
 use derive_new::new;
 use fasteval::{Compiler, Instruction, Slab};
 
-pub type TokenVec = Vec<Box<dyn Token>>;
+pub type TokenVec<'a> = Vec<Box<dyn Token + 'a>>;
 
 pub trait Token {
     fn apply(&self, context: Context) -> Context {
@@ -30,7 +30,7 @@ pub struct VariableChange(pub char, pub Expression);
 
 impl Token for VariableChange {}
 
-pub struct Loop(pub LoopCount, pub TokenVec);
+pub struct Loop<'a>(pub LoopCount, pub TokenVec<'a>);
 
 pub enum LoopCount {
     Litteral(usize),
@@ -43,13 +43,13 @@ impl Default for LoopCount {
     }
 }
 
-impl Token for Loop {}
+impl Token for Loop<'_> {}
 
-pub struct Tuplet(pub TokenVec);
+pub struct Tuplet<'a>(pub TokenVec<'a>);
 
-impl Token for Tuplet {}
+impl Token for Tuplet<'_> {}
 
-pub struct Slope<'a>(pub &'a VariableChange, pub TokenVec);
+pub struct Slope<'a>(pub &'a VariableChange, pub TokenVec<'a>);
 
 impl Token for Slope<'_> {}
 
diff --git a/src/parser.rs b/src/parser.rs
index cd99dd4..12b384d 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -32,10 +32,10 @@ pub struct Parser<'i, 'n, 's, 'v> {
     variables: &'v [char],
 }
 
-impl<'i> Parser<'i, '_, '_, '_> {
+impl<'i, 's> Parser<'i, '_, 's, '_> {
     pub fn parse_all(
         &self,
-    ) -> Result<Vec<Box<dyn Token>>, Error<nom_locate::LocatedSpan<&'i str>>> {
+    ) -> Result<Vec<Box<dyn Token + 's>>, Error<nom_locate::LocatedSpan<&'i str>>> {
         token_parser(self)
             .parse_complete(LocatedSpan::new(self.input))
             .finish()
@@ -43,11 +43,11 @@ impl<'i> Parser<'i, '_, '_, '_> {
     }
 }
 
-fn token_parser<'a>(
-    parser: &Parser,
+fn token_parser<'a, 's>(
+    parser: &Parser<'_, '_, 's, '_>,
 ) -> impl NomParser<
     LocatedSpan<&'a str>,
-    Output = Vec<Box<dyn Token>>,
+    Output = Vec<Box<dyn Token + 's>>,
     Error = nom::error::Error<LocatedSpan<&'a str>>,
 > {
     let space_or_comment = || {
@@ -71,7 +71,7 @@ fn token_parser<'a>(
     ))
 }
 
-fn into_box(token: impl Token + 'static) -> Box<dyn Token> {
+fn into_box<'a>(token: impl Token + 'a) -> Box<dyn Token + 'a> {
     Box::new(token)
 }
 
@@ -105,7 +105,7 @@ impl Note {
         Output = Self,
         Error = nom::error::Error<LocatedSpan<&'a str>>,
     > {
-        move |input: LocatedSpan<&'a str>| {
+        |input: LocatedSpan<&'a str>| {
             let mut parsers: Vec<Box<dyn Fn(LocatedSpan<&'a str>) -> TokenResult<'a, Self>>> =
                 notes
                     .iter()
@@ -135,8 +135,8 @@ impl VariableChange {
     }
 }
 
-impl Loop {
-    fn parser<'i, 'n, 's, 'v>(
+impl<'s> Loop<'s> {
+    fn parser<'i, 'n, 'v>(
         parser: &Parser<'i, 'n, 's, 'v>,
     ) -> impl Fn(LocatedSpan<&str>) -> TokenResult<Self> {
         |input| {
@@ -155,8 +155,8 @@ impl Loop {
     }
 }
 
-impl Tuplet {
-    fn parser<'i, 'n, 's, 'v>(
+impl<'s> Tuplet<'s> {
+    fn parser<'i, 'n, 'v>(
         parser: &Parser<'i, 'n, 's, 'v>,
     ) -> impl Fn(LocatedSpan<&str>) -> TokenResult<Self> {
         |input| {
@@ -172,18 +172,18 @@ impl<'s> Slope<'s> {
         parser: &Parser<'i, 'n, 's, 'v>,
     ) -> impl Fn(LocatedSpan<&'a str>) -> TokenResult<'a, Self> {
         |input| {
+            let iter: std::collections::hash_map::Iter<'s, String, VariableChange> =
+                parser.slopes.iter();
             delimited(
                 char('{'),
                 alt(
-                    parser
-                        .slopes
-                        .iter()
+                    iter
                         .map(|(k, v)| {
-                            Box::new(move |input: LocatedSpan<&'a str>| {
+                            Box::new(move|input: LocatedSpan<&'a str>| {
                                 value(v, tag(k.as_str())).parse(input)
                             })
                                 as Box<
-                                    dyn Fn(
+                                    dyn 's + Fn(
                                         LocatedSpan<&'a str>,
                                     )
                                         -> TokenResult<'a, &'s VariableChange>,
@@ -191,7 +191,7 @@ impl<'s> Slope<'s> {
                         })
                         .collect::<Vec<
                             Box<
-                                dyn Fn(LocatedSpan<&'a str>) -> TokenResult<'a, &'s VariableChange>,
+                                dyn 's + Fn(LocatedSpan<&'a str>) -> TokenResult<'a, &'s VariableChange>,
                             >,
                         >>()
                         .as_mut_slice(),
@@ -209,7 +209,7 @@ impl<'s> Slope<'s> {
 fn expression_parser<C: Into<char> + Ord + Display>(
     variables: &[C],
 ) -> impl Fn(LocatedSpan<&str>) -> TokenResult<Expression> {
-    move |input: LocatedSpan<&str>| {
+    |input: LocatedSpan<&str>| {
         let mut end_index = 0;
         let mut current_expression = None;
         while input.input_len() > end_index {
@@ -232,7 +232,7 @@ fn expression_parser<C: Into<char> + Ord + Display>(
                 current_expression = Some(e);
                 end_index += 1;
             } else if let Some(e) = current_expression {
-                return take(end_index).parse(input).map(move |(r, _)| (r, e));
+                return take(end_index).parse(input).map(|(r, _)| (r, e));
             } else {
                 return Err(nom::Err::Failure(nom::error::Error::new(
                     input,