Fix T61253: Wrong syntax highlighting when @ is used as multiplication

This is obviously not a perfect solution. However, to do proper
highlighting a more advanced Python parser would be necessary.
I think this patch implements a good heuristic to differentiate
between the cases when `@` is used for a decorator vs for
multiplication.

When `@` is directly followed by an identifier, it is interpreted
as decorated. Otherwise not.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D4495

1 files changed, 15 insertions, 11 deletions

diff --git a/source/blender/editors/space_text/text_format_py.c b/source/blender/editors/space_text/text_format_py.c
index d7dc9d625f5..85c3c4220c0 100644
--- a/source/blender/editors/space_text/text_format_py.c
+++ b/source/blender/editors/space_text/text_format_py.c
@@ -116,18 +116,22 @@ static int txtfmt_py_find_specialvar(const char *string)
 
 static int txtfmt_py_find_decorator(const char *string)
 {
-	if (string[0] == '@') {
-		int i = 1;
-		/* Whitespace is ok '@  foo' */
-		while (text_check_whitespace(string[i])) {
-			i++;
-		}
-		while (text_check_identifier(string[i])) {
-			i++;
-		}
-		return i;
+	if (string[0] != '@') {
+		return -1;
+	}
+	if (!text_check_identifier(string[1])) {
+		return -1;
 	}
-	return -1;
+	/* Interpret as matrix multiplication when followed by whitespace. */
+	if (text_check_whitespace(string[1])) {
+		return -1;
+	}
+
+	int i = 1;
+	while (text_check_identifier(string[i])) {
+		i++;
+	}
+	return i;
 }
 
 static int txtfmt_py_find_bool(const char *string)