Use the Scheme lexer if a scheme mode line is found

Emacs allows one to specify a property line at the top of the file (usually
first line, but if there is a shebang it's allowed on the second line) that can
include which mode to use. This can be used to discover which lexer to use.

1 files changed, 23 insertions, 1 deletions

diff --git a/cgit-pygments-wrapper b/cgit-pygments-wrapper
index f4e7a96..60a1ab1 100755
--- a/cgit-pygments-wrapper
+++ b/cgit-pygments-wrapper
@@ -14,6 +14,7 @@ CGIT_REPO_CLONE_URL ( = repo.clone-url setting )
 
 """
 import sys
+import re
 
 from pygments import highlight
 from pygments.formatters import HtmlFormatter
@@ -28,6 +29,25 @@ from pygments.lexers import (
 from pygments.lexers.shell import BashLexer
 from pygments.util import ClassNotFound, shebang_matches
 
+
+def modeline_matches(text, regex):
+    line_1_index = text.find("\n")
+    line_2_index = text.find("\n", line_1_index + 1)
+    regex = re.compile(r"-*- .*?%s.* -*-" % regex, re.IGNORECASE)
+
+    if line_1_index >= 0:
+        first_line = text[:line_1_index].lower()
+        second_line = text[line_1_index:line_2_index].lower()
+    else:
+        first_line = text.lower()
+        second_line = ""
+
+    return (
+        regex.search(first_line) is not None
+        or regex.search(second_line) is not None
+    )
+
+
 CommonLispLexer.filenames.append("*.asd")
 CommonLispLexer.filenames.append(".stumpwmrc")
 
@@ -43,7 +63,9 @@ formatter = HtmlFormatter(encoding="utf-8", style="autumn")
 try:
     if filename == "CMakeLists.txt":
         lexer = get_lexer_by_name("cmake")
-    elif shebang_matches(data, r"guile"):
+    elif shebang_matches(data, r"guile") or modeline_matches(
+        data, r"mode: scheme"
+    ):
         lexer = SchemeLexer()
     else:
         lexer = guess_lexer_for_filename(filename, data, encoding="utf-8")