From 2ac04496304e23aa315ef13b29a801e4a16f83df Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Sat, 22 Apr 2023 18:18:13 -0400
Subject: [PATCH] Unquote the text.

---
 src/compare/diff.rs |  5 +++--
 src/parser/sexp.rs  | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/compare/diff.rs b/src/compare/diff.rs
index 2343942e..f57eefc1 100644
--- a/src/compare/diff.rs
+++ b/src/compare/diff.rs
@@ -889,11 +889,12 @@ fn compare_plain_text<'s>(
     let mut this_status = DiffStatus::Good;
     let mut message = None;
     let text = emacs.as_text()?;
-    if text.text != rust.source {
+    let unquoted_text = text.unquote()?;
+    if unquoted_text != rust.source {
         this_status = DiffStatus::Bad;
         message = Some(format!(
             "(emacs != rust) {:?} != {:?}",
-            text.text, rust.source
+            unquoted_text, rust.source
         ));
     }
 
diff --git a/src/parser/sexp.rs b/src/parser/sexp.rs
index 85435482..da5f2b78 100644
--- a/src/parser/sexp.rs
+++ b/src/parser/sexp.rs
@@ -32,6 +32,45 @@ pub struct TextWithProperties<'s> {
     pub properties: Vec<Token<'s>>,
 }
 
+impl<'s> TextWithProperties<'s> {
+    pub fn unquote(&self) -> Result<String, Box<dyn std::error::Error>> {
+        let mut out = String::with_capacity(self.text.len());
+        if !self.text.starts_with(r#"""#) {
+            return Err("Quoted text does not start with quote.".into());
+        }
+        if !self.text.ends_with(r#"""#) {
+            return Err("Quoted text does not end with quote.".into());
+        }
+        let interior_text = &self.text[1..(self.text.len() - 1)];
+        let mut state = ParseState::Normal;
+        for current_char in interior_text.chars().into_iter() {
+            state = match (state, current_char) {
+                (ParseState::Normal, '\\') => ParseState::Escape,
+                (ParseState::Normal, _) => {
+                    out.push(current_char);
+                    ParseState::Normal
+                }
+                (ParseState::Escape, 'n') => {
+                    out.push('\n');
+                    ParseState::Normal
+                }
+                (ParseState::Escape, '\\') => {
+                    out.push('\\');
+                    ParseState::Normal
+                }
+                _ => todo!(),
+            };
+        }
+
+        Ok(out)
+    }
+}
+
+enum ParseState {
+    Normal,
+    Escape,
+}
+
 impl<'s> Token<'s> {
     pub fn as_list<'p>(&'p self) -> Result<&'p Vec<Token<'s>>, Box<dyn std::error::Error>> {
         Ok(match self {