Fix matrix delimiters

Fixes #200.

src/syntax/parser.rs

@@ -428,6 +428,7 @@ fn math_args(p: &mut Parser) {
             p.convert(SyntaxKind::Colon);
             named = Some(arg);
             arg = p.marker();
+            array = p.marker();
         }
 
         match p.current_text() {
@@ -448,7 +449,10 @@ fn math_args(p: &mut Parser) {
                 p.convert(SyntaxKind::Comma);
                 arg = p.marker();
                 namable = true;
-                named = None;
+                if named.is_some() {
+                    array = p.marker();
+                    named = None;
+                }
                 continue;
             }
             _ => {}
@@ -465,6 +469,9 @@ fn math_args(p: &mut Parser) {
 
     if arg != p.marker() {
         maybe_wrap_in_math(p, arg, named);
+        if named.is_some() {
+            array = p.marker();
+        }
     }
 
     if has_arrays && array != p.marker() {

tests/typ/math/matrix.typ

@@ -29,6 +29,30 @@ $ mat(
   ) $
 
 ---
-// Test alternative delimiter.
+// Test alternative delimiter with set rule.
 #set math.mat(delim: "[")
 $ mat(1, 2; 3, 4) $
+
+---
+// Test alternative math delimiter directly in call.
+#set align(center)
+#grid(
+  columns: 3,
+  gutter: 10pt,
+
+  $ mat(1, 2, delim: "[") $,
+  $ mat(1, 2; delim: "[") $,
+  $ mat(delim: "[", 1, 2) $,
+
+  $ mat(1; 2; delim: "[") $,
+  $ mat(1; delim: "[", 2) $,
+  $ mat(delim: "[", 1; 2) $,
+
+  $ mat(1, 2; delim: "[", 3, 4) $,
+  $ mat(delim: "[", 1, 2; 3, 4) $,
+  $ mat(1, 2; 3, 4; delim: "[") $,
+)
+
+---
+// Error: 13-14 expected array, found content
+$ mat(1, 2; 3, 4, delim: "[") $,