Refine dash replacement rules

A dash that isn't mid-word will be replaced with an em dash if in the
middle of a line, or with an en dash if at the start of a line.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/generate_html.rs b/src/generate_html.rs
index a6aa0b6..e329739 100644
--- a/src/generate_html.rs
+++ b/src/generate_html.rs
@@ -415,8 +415,11 @@ fn sanitize_text(text: &str, fancy: bool) -> String {
                 false => output.push('’'),
             },
             '-' if fancy => match prev.is_whitespace() && next.is_whitespace() {
-                true => output.push('—'),
-                false => output.push('-'),
+                true => match i > 0 {
+                    true => output.push('—'),  // em-dash, for mid-sentence
+                    false => output.push('–'),  // en-dash, for start of line
+                }
+                false => output.push('-'),      // regular dash, for mid-word
             }
             _ => output.push(*c),
         }