Fix retain labels.

This is a numeric value based on the character offset of -k from the beginning of the switches.

org_mode_samples/lesser_element/lesser_block/example/switches_with_label.org

@@ -1,3 +1,15 @@
-#+BEGIN_SRC elisp -n -r -l "((%s))"
+#+BEGIN_EXAMPLE elisp -n -r -l "((%s))"
    foo
-#+END_SRC
+#+END_EXAMPLE
+
+#+BEGIN_EXAMPLE elisp -k -n -r -l "((%s))"
+   foo
+#+END_EXAMPLE
+
+#+BEGIN_EXAMPLE elisp -k 8 -n -r -l "((%s))"
+   foo
+#+END_EXAMPLE
+
+#+BEGIN_EXAMPLE elisp -n -r -k -l "((%s))"
+   foo
+#+END_EXAMPLE

src/compare/diff.rs

@@ -18,6 +18,7 @@ use crate::types::AstNode;
 use crate::types::BabelCall;
 use crate::types::Bold;
 use crate::types::CenterBlock;
+use crate::types::CharOffsetInLine;
 use crate::types::CheckboxType;
 use crate::types::Citation;
 use crate::types::CitationReference;
@@ -1543,7 +1544,7 @@ fn compare_example_block<'b, 's>(
     _source: &'s str,
     emacs: &'b Token<'s>,
     rust: &'b ExampleBlock<'s>,
-) -> Result<DiffEntry<'b, 's>, Box<dyn std::error::Error>> {
+) -> Result<DiffEntry<'b, 's>, Box<dyn std::error::Error + 's>> {
     let mut this_status = DiffStatus::Good;
     let mut message = None;
 
@@ -1624,7 +1625,7 @@ fn compare_example_block<'b, 's>(
     }
 
     // Compare retain-labels
-    let retain_labels = get_property_boolean(emacs, ":retain-labels")?;
+    let retain_labels: Option<CharOffsetInLine> = get_property_numeric(emacs, ":retain-labels")?;
     if retain_labels != rust.retain_labels {
         this_status = DiffStatus::Bad;
         message = Some(format!(

src/parser/lesser_block.rs

@@ -31,6 +31,7 @@ use crate::parser::util::exit_matcher_parser;
 use crate::parser::util::get_consumed;
 use crate::parser::util::start_of_line;
 use crate::parser::util::text_until_exit;
+use crate::types::CharOffsetInLine;
 use crate::types::CommentBlock;
 use crate::types::ExampleBlock;
 use crate::types::ExportBlock;
@@ -167,7 +168,7 @@ pub(crate) fn example_block<'b, 'g, 'r, 's>(
                 parameters.label_format,
             )
         } else {
-            (None, None, true, true, None)
+            (None, None, None, true, None)
         }
     };
     Ok((
@@ -330,7 +331,7 @@ fn _lesser_block_begin<'b, 'g, 'r, 's, 'c>(
 struct ExampleSwitches<'s> {
     source: &'s str,
     number_lines: Option<SwitchNumberLines>,
-    retain_labels: bool,
+    retain_labels: Option<CharOffsetInLine>,
     use_labels: bool,
     label_format: Option<&'s str>,
 }
@@ -346,18 +347,17 @@ enum SwitchState {
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
 fn example_switches<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, ExampleSwitches<'s>> {
     let mut number_lines = None;
-    let mut retain_labels = true;
+    let mut retain_labels = None;
     let mut use_labels = true;
     let mut label_format = None;
-    let (remaining, (source, (words, _))) = consumed(tuple((
-        separated_list1(space1, map(switch_word, |val| Into::<&str>::into(val))),
-        space0,
-    )))(input)?;
+    let (remaining, (source, (words, _))) =
+        consumed(tuple((separated_list1(space1, switch_word), space0)))(input)?;
 
     let mut state = SwitchState::Normal;
     for word in words {
+        let normalized_word = Into::<&str>::into(word);
         loop {
-            match (&state, word) {
+            match (&state, normalized_word) {
                 (SwitchState::Normal, "-n") => {
                     state = SwitchState::NewLineNumber;
                 }
@@ -365,14 +365,20 @@ fn example_switches<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, ExampleSwitc
                     state = SwitchState::ContinuedLineNumber;
                 }
                 (SwitchState::Normal, "-r") => {
-                    retain_labels = false;
                     use_labels = false;
                 }
                 (SwitchState::Normal, "-l") => {
                     state = SwitchState::LabelFormat;
                 }
+                (SwitchState::Normal, "-k") => {
+                    let text_until_flag = input.get_until(word);
+                    let character_offset = Into::<&str>::into(text_until_flag).chars().count();
+                    let character_offset = CharOffsetInLine::try_from(character_offset)
+                        .expect("Character offset should fit in CharOffsetInLine");
+                    retain_labels = Some(character_offset);
+                }
                 (SwitchState::NewLineNumber, _) => {
-                    let val = word.parse::<LineNumber>();
+                    let val = normalized_word.parse::<LineNumber>();
                     if let Ok(val) = val {
                         if val < 0 {
                             number_lines = Some(SwitchNumberLines::New(0));
@@ -388,7 +394,7 @@ fn example_switches<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, ExampleSwitc
                     }
                 }
                 (SwitchState::ContinuedLineNumber, _) => {
-                    let val = word.parse::<LineNumber>();
+                    let val = normalized_word.parse::<LineNumber>();
                     if let Ok(val) = val {
                         if val < 0 {
                             number_lines = Some(SwitchNumberLines::Continued(0));
@@ -404,7 +410,7 @@ fn example_switches<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, ExampleSwitc
                     }
                 }
                 (SwitchState::LabelFormat, _) => {
-                    label_format = Some(word);
+                    label_format = Some(normalized_word);
                     state = SwitchState::Normal;
                 }
                 (SwitchState::Normal, _) => {}

src/types/lesser_element.rs

@@ -36,13 +36,15 @@ pub struct CommentBlock<'s> {
     pub contents: &'s str,
 }
 
+pub type CharOffsetInLine = u16;
+
 #[derive(Debug)]
 pub struct ExampleBlock<'s> {
     pub source: &'s str,
     pub name: &'s str,
     pub switches: Option<&'s str>,
     pub number_lines: Option<SwitchNumberLines>,
-    pub retain_labels: bool,
+    pub retain_labels: Option<CharOffsetInLine>,
     pub use_labels: bool,
     pub label_format: Option<&'s str>,
     pub contents: String,

src/types/mod.rs

@@ -37,6 +37,7 @@ pub use greater_element::Table;
 pub use greater_element::TableRow;
 pub use greater_element::TableRowType;
 pub use lesser_element::BabelCall;
+pub use lesser_element::CharOffsetInLine;
 pub use lesser_element::Clock;
 pub use lesser_element::Comment;
 pub use lesser_element::CommentBlock;