Add plaintext highlighter, escape ANSI in source

contrib/hldiff.py

@@ -3,10 +3,13 @@ from colorama import Fore, Style
 import sys
 import re
 
-patch = sys.stdin.read().replace("\r\n", "\n")
+ansi_escape = re.compile(r'\x1B\[[0-?]*[ -/]*[@-~]')
 stat_re = re.compile(r'(\+*)(\-*)')
 lines_re = re.compile(r'@@ (-\d+,\d+ \+\d+,\d+) @@')
 
+patch = sys.stdin.read().replace("\r\n", "\n")
+patch = ansi_escape.sub('', patch)
+
 hit_diff = False
 for line in patch.split("\n"):
     if line.startswith("diff "):

contrib/plaintext.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+from colorama import Fore, Style
+import sys
+import re
+
+# TODO: Wrap text to terminal width?
+
+ansi_escape = re.compile(r'\x1B\[[0-?]*[ -/]*[@-~]')
+# TODO: I guess this might vary from MUA to MUA. I've definitely seen localized
+# versions in the wild
+quote_prefix_re = re.compile(r"On [0-9: -]+( (AM|PM))?, .* wrote:")
+quote_re = re.compile(r">+ ")
+
+mail = sys.stdin.read().replace("\r\n", "\n")
+mail = ansi_escape.sub('', mail)
+
+for line in mail.split("\n"):
+    if quote_re.match(line) or quote_prefix_re.match(line):
+        print(f"{Style.DIM}{Fore.CYAN}{line}{Style.RESET_ALL}")
+    else:
+        print(line)