feat: implement basic highlighting (does not handle newlines yet)

helix-term/src/ui/editor.rs

@@ -1,3 +1,11 @@
+/// ```helix
+/// #(|hello world)#
+/// #(|hello world)#
+/// #[hello world|]#
+/// #(|hello world)#
+/// ```
+fn a() {}
+
 use crate::{
     commands::{self, OnKeyCallback, OnKeyCallbackKind},
     compositor::{Component, Context, Event, EventResult},

helix-term/src/ui/markdown.rs

@@ -5,13 +5,14 @@ use tui::{
     text::{Span, Spans, Text},
 };
 
-use std::sync::Arc;
+use std::{cmp::Ordering, collections::HashSet, sync::Arc};
 
 use pulldown_cmark::{CodeBlockKind, Event, HeadingLevel, Options, Parser, Tag, TagEnd};
 
 use helix_core::{
     syntax::{self, HighlightEvent, InjectionLanguageMarker, Syntax},
-    RopeSlice,
+    test::print,
+    Rope, RopeSlice,
 };
 use helix_view::{
     graphics::{Margin, Rect, Style},
@@ -71,6 +72,52 @@ pub fn highlighted_code_block<'a>(
             Box::new(highlight_iter)
         };
 
+    if language == "helix" {
+        let (text, selections) = print(text);
+        // let text = Rope::from(text).slice(..);
+
+        let style_cursor = get_theme("ui.cursor");
+        let style_cursor_primary = get_theme("ui.cursor.primary");
+        let style_selection = get_theme("ui.selection");
+        let style_selection_primary = get_theme("ui.selection.primary");
+        let style_text = get_theme("ui.text");
+
+        let mut ranges2 = HashSet::new();
+        let mut cursors = HashSet::new();
+        let primary_idx = selections.primary_index();
+
+        for range in selections.iter() {
+            ranges2.extend(range.from()..range.to());
+            cursors.insert(if range.head > range.anchor {
+                range.head.saturating_sub(1)
+            } else {
+                range.head
+            });
+        }
+
+        for (idx, ch) in text.chars().enumerate() {
+            let is_cursor = cursors.contains(&idx);
+            let is_selection = ranges2.contains(&idx);
+
+            let style = if is_cursor {
+                if idx == primary_idx {
+                    style_cursor_primary
+                } else {
+                    style_cursor
+                }
+            } else if is_selection {
+                if idx == primary_idx {
+                    style_selection_primary
+                } else {
+                    style_selection
+                }
+            } else {
+                style_text
+            };
+
+            spans.push(Span::styled(ch.to_string(), style));
+        }
+    } else {
         let mut highlights = Vec::new();
         for event in highlight_iter {
             match event {
@@ -111,6 +158,7 @@ pub fn highlighted_code_block<'a>(
                 }
             }
         }
+    }
 
     if !spans.is_empty() {
         let spans = std::mem::take(&mut spans);

lol.helix

@@ -0,0 +1,4 @@
+hello world #[|lol]#
+hello world #[lol|]#
+hello wor#(| hello world )#
+#(lol|)#