From c73ed9310d8162b71183688de62bf8c1fc8420df Mon Sep 17 00:00:00 2001
From: Jonas Maier <jonas@x77.dev>
Date: Mon, 1 Jun 2026 21:55:53 +0200
Subject: syntax highlighting for regex; syntax highlighting syntax errors

---
 src/parse/mod.rs | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

(limited to 'src/parse/mod.rs')

diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index b3855a8..b07d5f9 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -426,7 +426,7 @@ impl Parse for Block {
     fn parse(b: &mut Cursor<'_>) -> Result<Self> {
         let mut commands = Vec::new();
 
-        b.consume_keyword(Keyword::OpenBrace)?;
+        b.expect_keyword(Keyword::OpenBrace)?;
 
         loop {
             while {
@@ -444,7 +444,7 @@ impl Parse for Block {
             commands.push(cmd);
         }
 
-        let finished_parsing = match b.consume_keyword(Keyword::CloseBrace) {
+        let finished_parsing = match b.expect_keyword(Keyword::CloseBrace) {
             Ok(_) => true,
             Err(_) if b.is_completion() => false,
             Err(e) => Err(e)?,
@@ -1365,7 +1365,10 @@ impl From<OtherHighlights> for HighlightKind {
 pub enum OtherHighlights {
     String,
     Variable,
+    Regex,
+    RegexSymbol,
     Escapes,
+    SyntaxError,
 }
 
 impl OtherHighlights {
@@ -1374,6 +1377,9 @@ impl OtherHighlights {
             OtherHighlights::String => b"string",
             OtherHighlights::Variable => b"var",
             OtherHighlights::Escapes => b"escape",
+            OtherHighlights::Regex => b"regex",
+            OtherHighlights::RegexSymbol => b"regexsym",
+            OtherHighlights::SyntaxError => b"syntax_error",
         }
     }
 }
@@ -1634,6 +1640,31 @@ impl<'a> Cursor<'a> {
         T::parse(self)
     }
 
+    fn expect_keyword(&mut self, kw: Keyword) -> Result<()> {
+        if !self.is_completion() {
+            return self.consume_keyword(kw)
+        }
+
+        // very lax parsing that consumes everything in its way until the keyword arrives
+        self.spaces();
+        let begin = self.loc();
+        loop {
+            let end = self.loc_u32();
+            if self.consume_keyword(kw).is_ok() {
+                if end > begin.start {
+                    self.highlight(begin.to(end), OtherHighlights::SyntaxError);
+                }
+                return Ok(());
+            } else if self.has() {
+                self.adv();
+            } else {
+                break;
+            }
+        }
+        self.highlight_from(begin, OtherHighlights::SyntaxError);
+        Err(ParseError::ExpectedKeyword(kw))
+    }
+
     fn consume_keyword(&mut self, kw: Keyword) -> Result<()> {
         let bytes = kw.as_bytes();
 
-- 
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