Ensure the extended keyboard protocol key encoding is stable

Also use base85 instead of base64 for keyname encoding to reduce average
length

kitty/key_encoding.py

@@ -0,0 +1,190 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
+
+import string
+
+from . import fast_data_types as defines
+
+# ENCODING {{{
+ENCODING = {
+    '0': 'G',
+    '1': 'H',
+    '2': 'I',
+    '3': 'J',
+    '4': 'K',
+    '5': 'L',
+    '6': 'M',
+    '7': 'N',
+    '8': 'O',
+    '9': 'P',
+    'A': 'S',
+    'APOSTROPHE': 'B',
+    'B': 'T',
+    'BACKSLASH': 't',
+    'BACKSPACE': '1',
+    'C': 'U',
+    'CAPS LOCK': ':',
+    'COMMA': 'C',
+    'D': 'V',
+    'DELETE': '3',
+    'DOWN': '6',
+    'E': 'W',
+    'END': '-',
+    'ENTER': 'z',
+    'EQUAL': 'R',
+    'ESCAPE': 'y',
+    'F': 'X',
+    'F1': '/',
+    'F10': ']',
+    'F11': '{',
+    'F12': '}',
+    'F13': '@',
+    'F14': '%',
+    'F15': '$',
+    'F16': '#',
+    'F17': 'BA',
+    'F18': 'BB',
+    'F19': 'BC',
+    'F2': '*',
+    'F20': 'BD',
+    'F21': 'BE',
+    'F22': 'BF',
+    'F23': 'BG',
+    'F24': 'BH',
+    'F25': 'BI',
+    'F3': '?',
+    'F4': '&',
+    'F5': '<',
+    'F6': '>',
+    'F7': '(',
+    'F8': ')',
+    'F9': '[',
+    'G': 'Y',
+    'GRAVE ACCENT': 'v',
+    'H': 'Z',
+    'HOME': '.',
+    'I': 'a',
+    'INSERT': '2',
+    'J': 'b',
+    'K': 'c',
+    'KP 0': 'BJ',
+    'KP 1': 'BK',
+    'KP 2': 'BL',
+    'KP 3': 'BM',
+    'KP 4': 'BN',
+    'KP 5': 'BO',
+    'KP 6': 'BP',
+    'KP 7': 'BQ',
+    'KP 8': 'BR',
+    'KP 9': 'BS',
+    'KP ADD': 'BX',
+    'KP DECIMAL': 'BT',
+    'KP DIVIDE': 'BU',
+    'KP ENTER': 'BY',
+    'KP EQUAL': 'BZ',
+    'KP MULTIPLY': 'BV',
+    'KP SUBTRACT': 'BW',
+    'L': 'd',
+    'LEFT': '5',
+    'LEFT ALT': 'Bc',
+    'LEFT BRACKET': 's',
+    'LEFT CONTROL': 'Bb',
+    'LEFT SHIFT': 'Ba',
+    'LEFT SUPER': 'Bd',
+    'M': 'e',
+    'MINUS': 'D',
+    'N': 'f',
+    'NUM LOCK': '=',
+    'O': 'g',
+    'P': 'h',
+    'PAGE DOWN': '9',
+    'PAGE UP': '8',
+    'PAUSE': '!',
+    'PERIOD': 'E',
+    'PRINT SCREEN': '^',
+    'Q': 'i',
+    'R': 'j',
+    'RIGHT': '4',
+    'RIGHT ALT': 'Bg',
+    'RIGHT BRACKET': 'u',
+    'RIGHT CONTROL': 'Bf',
+    'RIGHT SHIFT': 'Be',
+    'RIGHT SUPER': 'Bh',
+    'S': 'k',
+    'SCROLL LOCK': '+',
+    'SEMICOLON': 'Q',
+    'SLASH': 'F',
+    'SPACE': 'A',
+    'T': 'l',
+    'TAB': '0',
+    'U': 'm',
+    'UP': '7',
+    'V': 'n',
+    'W': 'o',
+    'WORLD 1': 'w',
+    'WORLD 2': 'x',
+    'X': 'p',
+    'Y': 'q',
+    'Z': 'r'
+}
+
+# END_ENCODING }}}
+
+
+def encode(
+    integer,
+    chars=string.ascii_uppercase + string.ascii_lowercase + string.digits +
+    '.-:+=^!/*?&<>()[]{}@%$#'
+):
+    ans = ''
+    d = len(chars)
+    while True:
+        integer, remainder = divmod(integer, d)
+        ans = chars[remainder] + ans
+        if integer == 0:
+            break
+    return ans
+
+
+def symbolic_name(glfw_name):
+    return glfw_name[9:].replace('_', ' ')
+
+
+def generate_extended_key_map(symbolic=False):
+    keys = (a for a in dir(defines) if a.startswith('GLFW_KEY_'))
+    ans = {}
+    for k in keys:
+        name = symbolic_name(k)
+        enc = ENCODING.get(name)
+        if name is not None:
+            ans[getattr(defines, k)] = enc
+    return ans
+
+
+def update_encoding():
+    import re
+    import subprocess
+    from pprint import pformat
+    keys = {a for a in dir(defines) if a.startswith('GLFW_KEY_')}
+    ans = ENCODING
+    i = len(ans)
+    for k in sorted(keys, key=lambda k: getattr(defines, k)):
+        val = getattr(defines, k)
+        name = symbolic_name(k)
+        if val < defines.GLFW_KEY_LAST and val != defines.GLFW_KEY_UNKNOWN and name not in ans:
+            ans[name] = encode(i)
+            i += 1
+    with open(__file__, 'r+') as f:
+        raw = f.read()
+        nraw = re.sub(
+            r'^ENCODING = {.+^# END_ENCODING',
+            'ENCODING = {}\n# END_ENCODING'.format(pformat(ans, indent=4)),
+            raw,
+            flags=re.MULTILINE | re.DOTALL
+        )
+        if raw == nraw:
+            raise SystemExit('Failed to replace ENCODING dict')
+        f.seek(0), f.truncate()
+        f.write(nraw)
+    subprocess.check_call(['yapf', '-i', __file__])