From 6c004ba3bd9f46863abfeda25721036d444fed71 Mon Sep 17 00:00:00 2001
From: Sam Johnson <sam@durosoft.com>
Date: Tue, 2 Apr 2024 18:45:59 -0400
Subject: [PATCH] WIP

---
 Cargo.lock    |  4 ++--
 Cargo.toml    |  2 +-
 src/source.rs | 24 ++++++++++++++----------
 src/span.rs   | 20 +++++++++++++-------
 4 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 7bcbfd6..441be24 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -413,9 +413,9 @@ checksum = "e86697c916019a8588c99b5fac3cead74ec0b4b819707a682fd4d23fa0ce1ba1"
 
 [[package]]
 name = "safe-string"
-version = "0.1.1"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9b95c754451a4a8b00011e37320894983b28dbded186ac4c8786a71a2d61f22"
+checksum = "c699d55ef046e66db4508d9cb09ba1220a42e9bb5f3dac0469e266031c8fcc6e"
 
 [[package]]
 name = "seahash"
diff --git a/Cargo.toml b/Cargo.toml
index 7ddfd05..a8dd984 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,4 +16,4 @@ license = "MIT"
 quoth-macros = { path = "quoth-macros", version = "0.1.5" }
 regex = "1.10"
 rust_decimal = "1"
-safe-string = "0.1.1"
+safe-string = "0.1.5"
diff --git a/src/source.rs b/src/source.rs
index 2f6e486..0b986cf 100644
--- a/src/source.rs
+++ b/src/source.rs
@@ -1,6 +1,5 @@
 //! home of [`Source`] and related types.
 
-#[cfg(doc)]
 use super::*;
 
 use std::{
@@ -11,14 +10,14 @@ use std::{
 /// Represents source text that can be indexed into to define individual [`Span`]s.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Source {
-    text: String,
+    text: IndexedString,
     path: Option<PathBuf>,
 }
 
 impl Source {
     /// Returns the underlying text of this [`Source`], with original formatting.
-    pub fn source_text(&self) -> &str {
-        &self.text
+    pub fn source_text(&self) -> IndexedSlice {
+        self.text.as_slice()
     }
 
     /// Returns the path of the file that this [`Source`] was read from, if it was read from a file.
@@ -26,21 +25,26 @@ impl Source {
         self.path.as_ref().map(|path| path.as_path())
     }
 
-    /// Returns the length of the underlying text of this [`Source`].
-    pub fn from_str(string: impl Into<String>) -> Self {
+    /// Creates a new [`Source`] from a string.
+    pub fn from_str(string: impl AsRef<str>) -> Self {
         Source {
-            text: string.into(),
+            text: IndexedString::from_str(string.as_ref()),
             path: None,
         }
     }
 
+    /// Creates a new [`Source`] from an [`IndexedString`].
+    pub fn from_indexed_string(text: IndexedString) -> Self {
+        Source { text, path: None }
+    }
+
     /// Reads the contents of a file and returns a [`Source`] with the file's text.
     ///
     /// Since no parsing is done at this stage, only IO or encoding errors will be returned,
     /// regardless of the validity of the syntax in the file.
     pub fn from_file(path: impl AsRef<Path>) -> core::result::Result<Self, std::io::Error> {
         std::fs::read_to_string(path.as_ref()).map(|text| Source {
-            text,
+            text: IndexedString::from(&text),
             path: Some(path.as_ref().to_path_buf()),
         })
     }
@@ -52,7 +56,7 @@ impl Source {
 }
 
 impl Deref for Source {
-    type Target = String;
+    type Target = IndexedString;
 
     fn deref(&self) -> &Self::Target {
         &self.text
@@ -62,7 +66,7 @@ impl Deref for Source {
 impl<S: ToString> From<S> for Source {
     fn from(value: S) -> Self {
         Source {
-            text: value.to_string(),
+            text: IndexedString::from(value.to_string()),
             path: None,
         }
     }
diff --git a/src/span.rs b/src/span.rs
index c766b69..c2ad5cb 100644
--- a/src/span.rs
+++ b/src/span.rs
@@ -77,8 +77,8 @@ impl Span {
     }
 
     /// Returns the text of the [`Source`] that this [`Span`] is associated with.
-    pub fn source_text(&self) -> &str {
-        &self.source[self.byte_range.clone()]
+    pub fn source_text(&self) -> IndexedSlice {
+        self.source.slice(self.byte_range.clone())
     }
 
     /// Returns the path of the [`Source`] that this [`Span`] is associated with, if it has one.
@@ -99,8 +99,8 @@ impl Span {
     pub fn start(&self) -> LineCol {
         let mut line = 0;
         let mut col = 0;
-        for c in self.source[0..self.byte_range.start].chars() {
-            if c == '\n' {
+        for c in self.source.slice(0..self.byte_range.start).chars() {
+            if *c == '\n' {
                 col = 0;
                 line += 1;
             } else {
@@ -113,8 +113,12 @@ impl Span {
     /// Returns the line and column of the end of this [`Span`] within the [`Source`].
     pub fn end(&self) -> LineCol {
         let LineCol { mut line, mut col } = self.start();
-        for c in self.source[self.byte_range.start..self.byte_range.end].chars() {
-            if c == '\n' {
+        for c in self
+            .source
+            .slice(self.byte_range.start..self.byte_range.end)
+            .chars()
+        {
+            if *c == '\n' {
                 col = 0;
                 line += 1;
             } else {
@@ -125,7 +129,7 @@ impl Span {
     }
 
     /// Returns an iterator over the lines of the [`Source`] that this [`Span`] is associated with,
-    pub fn source_lines(&self) -> impl Iterator<Item = (&str, Range<usize>)> {
+    pub fn source_lines(&self) -> impl Iterator<Item = (IndexedString, Range<usize>)> {
         let start_line_col = self.start();
         let end_line_col = self.end();
         let start_col = start_line_col.col;
@@ -133,9 +137,11 @@ impl Span {
         let end_line = end_line_col.line;
         let end_col = end_line_col.col;
         self.source
+            .as_str()
             .lines()
             .enumerate()
             .filter_map(move |(i, line)| {
+                let line = IndexedString::from(line);
                 if start_line == end_line && end_line == i {
                     Some((line, start_col..end_col))
                 } else if i == start_line {