From fb99fd2b3987db14e0a9f37ba55a38bcbd64616a Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Sun, 29 Oct 2023 10:32:05 -0400
Subject: [PATCH] Get the source code lines.

---
 src/intermediate/src_block.rs |  11 +--
 src/intermediate/util.rs      | 126 ++++++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+), 4 deletions(-)

diff --git a/src/intermediate/src_block.rs b/src/intermediate/src_block.rs
index 9fa4a0d..9577179 100644
--- a/src/intermediate/src_block.rs
+++ b/src/intermediate/src_block.rs
@@ -1,6 +1,7 @@
 use crate::error::CustomError;
 
 use super::registry::Registry;
+use super::util::GetFullLines;
 
 #[derive(Debug)]
 pub(crate) struct ISrcBlock {
@@ -12,9 +13,11 @@ impl ISrcBlock {
         registry: &mut Registry<'parse>,
         original: &organic::types::SrcBlock<'parse>,
     ) -> Result<ISrcBlock, CustomError> {
-        // let contents = original.contents.
-        Ok(ISrcBlock {
-            lines: Vec::new(), // TODO
-        })
+        let lines = original
+            .contents
+            .full_lines()
+            .map(|s| s.to_owned())
+            .collect();
+        Ok(ISrcBlock { lines })
     }
 }
diff --git a/src/intermediate/util.rs b/src/intermediate/util.rs
index b482b98..f2718dc 100644
--- a/src/intermediate/util.rs
+++ b/src/intermediate/util.rs
@@ -46,3 +46,129 @@ enum CoalesceWhitespace {
     Normal,
     HasWhitespace { in_whitespace: bool, ret: String },
 }
+
+pub(crate) struct FullLinesIterator<'i> {
+    inner: Option<&'i str>,
+}
+
+impl<'i> Iterator for FullLinesIterator<'i> {
+    type Item = &'i str;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if let Some(inner) = self.inner {
+            for (i, c) in inner.char_indices() {
+                if c == '\n' {
+                    let (current_line, remainder) = inner.split_at(i + 1);
+                    self.inner = Some(remainder);
+                    return Some(current_line);
+                }
+            }
+            if inner.is_empty() {
+                None
+            } else {
+                let final_unterminated_line = Some(inner);
+                self.inner = None;
+                final_unterminated_line
+            }
+        } else {
+            None
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        if let Some(inner) = self.inner {
+            let line_count = {
+                inner.bytes().filter(|b| *b == b'\n').count()
+                    + (if inner.ends_with('\n') { 0 } else { 1 })
+            };
+            (line_count, Some(line_count))
+        } else {
+            (0, Some(0))
+        }
+    }
+}
+
+impl ExactSizeIterator for FullLinesIterator<'_> {}
+
+pub(crate) trait GetFullLines {
+    fn full_lines(&self) -> FullLinesIterator<'_>;
+}
+
+impl<'s, S: AsRef<str>> GetFullLines for S {
+    fn full_lines(&self) -> FullLinesIterator<'_> {
+        let inner = self.as_ref();
+        FullLinesIterator {
+            inner: if inner.is_empty() { None } else { Some(inner) },
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_full_lines_iterator() {
+        {
+            let input = "foo\nbar\nbaz";
+            assert_eq!(input.lines().count(), input.full_lines().count());
+            assert_eq!(input.lines().count(), input.full_lines().len());
+            assert_eq!(input.lines().collect::<Vec<_>>(), vec!["foo", "bar", "baz"]);
+            assert_eq!(
+                input.full_lines().collect::<Vec<_>>(),
+                vec!["foo\n", "bar\n", "baz"]
+            );
+        }
+
+        {
+            // Trailing newline
+            let input = "foo\nbar\nbaz\n";
+            assert_eq!(input.lines().count(), input.full_lines().count());
+            assert_eq!(input.lines().count(), input.full_lines().len());
+            assert_eq!(input.lines().collect::<Vec<_>>(), vec!["foo", "bar", "baz"]);
+            assert_eq!(
+                input.full_lines().collect::<Vec<_>>(),
+                vec!["foo\n", "bar\n", "baz\n"]
+            );
+        }
+
+        {
+            // Leading newline
+            let input = "\nfoo\nbar\nbaz";
+            assert_eq!(input.lines().count(), input.full_lines().count());
+            assert_eq!(input.lines().count(), input.full_lines().len());
+            assert_eq!(
+                input.lines().collect::<Vec<_>>(),
+                vec!["", "foo", "bar", "baz"]
+            );
+            assert_eq!(
+                input.full_lines().collect::<Vec<_>>(),
+                vec!["\n", "foo\n", "bar\n", "baz"]
+            );
+        }
+
+        {
+            // Double newline
+            let input = "foo\nbar\n\nbaz";
+            assert_eq!(input.lines().count(), input.full_lines().count());
+            assert_eq!(input.lines().count(), input.full_lines().len());
+            assert_eq!(
+                input.lines().collect::<Vec<_>>(),
+                vec!["foo", "bar", "", "baz"]
+            );
+            assert_eq!(
+                input.full_lines().collect::<Vec<_>>(),
+                vec!["foo\n", "bar\n", "\n", "baz"]
+            );
+        }
+
+        {
+            // Empty
+            let input = "";
+            assert_eq!(input.lines().count(), input.full_lines().count());
+            assert_eq!(input.lines().count(), input.full_lines().len());
+            assert_eq!(input.lines().collect::<Vec<_>>(), Vec::<&str>::new());
+            assert_eq!(input.full_lines().collect::<Vec<_>>(), Vec::<&str>::new());
+        }
+    }
+}