diff --git a/build.rs b/build.rs
index 058a8ee..5d6f10e 100644
--- a/build.rs
+++ b/build.rs
@@ -74,7 +74,7 @@ fn write_header(test_file: &mut File) {
 use organic::compare_document;
 use organic::parser::parse;
 use organic::emacs_parse_anonymous_org_document;
-use organic::parser::sexp::sexp;
+use organic::sexp;
 
 "#
     )
diff --git a/src/bin_compare.rs b/src/bin_compare.rs
index da41af8..8f91501 100644
--- a/src/bin_compare.rs
+++ b/src/bin_compare.rs
@@ -10,7 +10,7 @@ use organic::emacs_parse_file_org_document;
 use organic::get_emacs_version;
 use organic::get_org_mode_version;
 use organic::parser::parse_with_settings;
-use organic::parser::sexp::sexp;
+use organic::sexp;
 use organic::GlobalSettings;
 use organic::LocalFileAccessInterface;
 
@@ -66,8 +66,7 @@ fn run_anonymous_parse<P: AsRef<str>>(org_contents: P) -> Result<(), Box<dyn std
     eprintln!("Using org-mode version: {}", get_org_mode_version()?.trim());
     let rust_parsed = parse(org_contents)?;
     let org_sexp = emacs_parse_anonymous_org_document(org_contents)?;
-    let (_remaining, parsed_sexp) =
-        sexp(org_sexp.as_str()).map_err(|e| e.to_string())?;
+    let (_remaining, parsed_sexp) = sexp(org_sexp.as_str()).map_err(|e| e.to_string())?;
 
     println!("{}\n\n\n", org_contents);
     println!("{}", org_sexp);
@@ -103,8 +102,7 @@ fn run_parse_on_file<P: AsRef<Path>>(org_path: P) -> Result<(), Box<dyn std::err
     };
     let rust_parsed = parse_with_settings(org_contents, &global_settings)?;
     let org_sexp = emacs_parse_file_org_document(org_path)?;
-    let (_remaining, parsed_sexp) =
-        sexp(org_sexp.as_str()).map_err(|e| e.to_string())?;
+    let (_remaining, parsed_sexp) = sexp(org_sexp.as_str()).map_err(|e| e.to_string())?;
 
     println!("{}\n\n\n", org_contents);
     println!("{}", org_sexp);
diff --git a/src/compare/diff.rs b/src/compare/diff.rs
index 1f26220..f4f194c 100644
--- a/src/compare/diff.rs
+++ b/src/compare/diff.rs
@@ -1,11 +1,11 @@
 use std::collections::BTreeSet;
 use std::collections::HashSet;
 
+use super::sexp::unquote;
+use super::sexp::Token;
 use super::util::assert_bounds;
 use super::util::assert_name;
 use super::util::get_property;
-use crate::parser::sexp::unquote;
-use crate::parser::sexp::Token;
 use crate::types::AngleLink;
 use crate::types::Bold;
 use crate::types::Citation;
diff --git a/src/compare/mod.rs b/src/compare/mod.rs
index 094dda5..ae31724 100644
--- a/src/compare/mod.rs
+++ b/src/compare/mod.rs
@@ -1,8 +1,10 @@
 mod diff;
 mod parse;
+mod sexp;
 mod util;
 pub use diff::compare_document;
 pub use parse::emacs_parse_anonymous_org_document;
 pub use parse::emacs_parse_file_org_document;
 pub use parse::get_emacs_version;
 pub use parse::get_org_mode_version;
+pub use sexp::sexp;
diff --git a/src/parser/sexp.rs b/src/compare/sexp.rs
similarity index 87%
rename from src/parser/sexp.rs
rename to src/compare/sexp.rs
index d546552..d06bbf0 100644
--- a/src/parser/sexp.rs
+++ b/src/compare/sexp.rs
@@ -16,9 +16,6 @@ use nom::sequence::delimited;
 use nom::sequence::preceded;
 use nom::sequence::tuple;
 
-use super::org_source::convert_error;
-use super::org_source::OrgSource;
-use super::util::get_consumed;
 use crate::error::Res;
 
 #[derive(Debug)]
@@ -99,6 +96,25 @@ impl<'s> Token<'s> {
     }
 }
 
+/// Check if the child string slice is a slice of the parent string slice.
+fn is_slice_of(parent: &str, child: &str) -> bool {
+    let parent_start = parent.as_ptr() as usize;
+    let parent_end = parent_start + parent.len();
+    let child_start = child.as_ptr() as usize;
+    let child_end = child_start + child.len();
+    child_start >= parent_start && child_end <= parent_end
+}
+
+/// Get a slice of the string that was consumed in a parser using the original input to the parser and the remaining input after the parser.
+pub fn get_consumed<'s>(input: &'s str, remaining: &'s str) -> &'s str {
+    assert!(is_slice_of(input, remaining));
+    let source = {
+        let offset = remaining.as_ptr() as usize - input.as_ptr() as usize;
+        &input[..offset]
+    };
+    source.into()
+}
+
 pub(crate) fn unquote(text: &str) -> Result<String, Box<dyn std::error::Error>> {
     let mut out = String::with_capacity(text.len());
     if !text.starts_with(r#"""#) {
@@ -138,21 +154,18 @@ pub(crate) fn unquote(text: &str) -> Result<String, Box<dyn std::error::Error>>
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
 pub fn sexp<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, _) = multispace0(input)?;
-    let remaining = OrgSource::new(remaining);
-    let (remaining, tkn) = token(remaining)
-        .map(|(rem, out)| (Into::<&str>::into(rem), out))
-        .map_err(convert_error)?;
+    let (remaining, tkn) = token(remaining).map(|(rem, out)| (Into::<&str>::into(rem), out))?;
     let (remaining, _) = multispace0(remaining)?;
     Ok((remaining, tkn))
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn token<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn token<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     alt((list, vector, atom))(input)
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn list<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn list<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, _) = tag("(")(input)?;
     let (remaining, children) = delimited(
         multispace0,
@@ -164,7 +177,7 @@ fn list<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn vector<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn vector<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, _) = tag("[")(input)?;
     let (remaining, children) = delimited(
         multispace0,
@@ -176,7 +189,7 @@ fn vector<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn atom<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn atom<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     not(peek(one_of(")]")))(input)?;
     alt((
         text_with_properties,
@@ -187,7 +200,7 @@ fn atom<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn unquoted_atom<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn unquoted_atom<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, body) = take_till1(|c| match c {
         ' ' | '\t' | '\r' | '\n' | ')' | ']' => true,
         _ => false,
@@ -196,7 +209,7 @@ fn unquoted_atom<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn quoted_atom<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn quoted_atom<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, _) = tag(r#"""#)(input)?;
     let (remaining, _) = escaped(
         take_till1(|c| match c {
@@ -212,7 +225,7 @@ fn quoted_atom<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
-fn hash_notation<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn hash_notation<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, _) = tag("#<")(input)?;
     let (remaining, _body) = take_till1(|c| match c {
         '>' => true,
@@ -223,7 +236,7 @@ fn hash_notation<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
     Ok((remaining, Token::Atom(source.into())))
 }
 
-fn text_with_properties<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, Token<'s>> {
+fn text_with_properties<'s>(input: &'s str) -> Res<&'s str, Token<'s>> {
     let (remaining, _) = tag("#(")(input)?;
     let (remaining, (text, props)) = delimited(
         multispace0,
diff --git a/src/compare/util.rs b/src/compare/util.rs
index c14a794..4e8668b 100644
--- a/src/compare/util.rs
+++ b/src/compare/util.rs
@@ -1,4 +1,4 @@
-use crate::parser::sexp::Token;
+use super::sexp::Token;
 use crate::types::Source;
 
 /// Check if the child string slice is a slice of the parent string slice.
diff --git a/src/lib.rs b/src/lib.rs
index afc3796..bbd1944 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -15,6 +15,8 @@ pub use compare::emacs_parse_file_org_document;
 pub use compare::get_emacs_version;
 #[cfg(feature = "compare")]
 pub use compare::get_org_mode_version;
+#[cfg(feature = "compare")]
+pub use compare::sexp;
 
 mod context;
 mod error;
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 6b5b44b..b19f9ca 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -37,8 +37,6 @@ mod property_drawer;
 mod radio_link;
 mod regular_link;
 mod section;
-#[cfg(feature = "compare")]
-pub mod sexp;
 mod statistics_cookie;
 mod subscript_and_superscript;
 mod table;