diff kitten: add options to ignore paths when comparing directories

Tested locally & over SSH:

    $ kitty +kitten diff /local/path /local/path2
    $ kitty +kitten diff /local/path ssh:remote:/path

kittens/diff/collect.py

@@ -4,6 +4,7 @@
 import os
 import re
 from contextlib import suppress
+from fnmatch import fnmatch
 from functools import lru_cache
 from hashlib import md5
 from kitty.guess_mime_type import guess_type
@@ -37,6 +38,9 @@ class Segment:
 
 class Collection:
 
+    file_ignores = ['']
+    ignore_paths = ['']
+
     def __init__(self) -> None:
         self.changes: Dict[str, str] = {}
         self.renames: Dict[str, str] = {}
@@ -113,7 +117,11 @@ def collect_files(collection: Collection, left: str, right: str) -> None:
 
     def walk(base: str, names: Set[str], pmap: Dict[str, str]) -> None:
         for dirpath, dirnames, filenames in os.walk(base):
+            if any(fnmatch(dirpath, f"*/{pat}") for pat in collection.ignore_paths):
+                continue
             for filename in filenames:
+                if any(fnmatch(filename, f"{pat}") for pat in collection.file_ignores):
+                    continue
                 path = os.path.abspath(os.path.join(dirpath, filename))
                 path_name_map[path] = name = os.path.relpath(path, base)
                 names.add(name)

kittens/diff/main.py

@@ -655,6 +655,8 @@ def main(args: List[str]) -> None:
     opts = init_config(cli_opts)
     set_diff_command(opts.diff_cmd)
     lines_for_path.replace_tab_by = opts.replace_tab_by
+    Collection.file_ignores = opts.file_ignores
+    Collection.ignore_paths = opts.ignore_paths
     left, right = map(get_remote_file, (left, right))
     if os.path.isdir(left) != os.path.isdir(right):
         raise SystemExit('The items to be diffed should both be either directories or files. Comparing a directory to a file is not valid.')

kittens/diff/options/definition.py

@@ -47,6 +47,17 @@ opt('replace_tab_by', '\\x20\\x20\\x20\\x20',
     option_type='python_string',
     long_text='The string to replace tabs with. Default is to use four spaces.'
     )
+
+opt('file_ignores', '',
+    option_type='pattern_list',
+    long_text='List of file patterns that are ignored when directories are compared'
+    )
+
+opt('ignore_paths', '',
+    option_type='pattern_list',
+    long_text='List of directory patterns that are ignored when directories are compared'
+    )
+
 egr()  # }}}
 
 # colors {{{

kittens/diff/options/parse.py

@@ -1,7 +1,7 @@
 # generated by gen-config.py DO NOT edit
 
 import typing
-from kittens.diff.options.utils import parse_map, syntax_aliases
+from kittens.diff.options.utils import parse_map, pattern_list, syntax_aliases
 from kitty.conf.utils import merge_dicts, positive_int, python_string, to_color, to_color_or_none
 
 
@@ -86,6 +86,12 @@ class Parser:
         for k in parse_map(val):
             ans['map'].append(k)
 
+    def file_ignores(self, val: str, ans: typing.Dict[str, typing.List[str]]):
+        ans['file_ignores'] = pattern_list(val)
+
+    def ignore_paths(self, val: str, ans: typing.Dict[str, typing.List[str]]):
+        ans['ignore_paths'] = pattern_list(val)
+
 
 def create_result_dict() -> typing.Dict[str, typing.Any]:
     return {

kittens/diff/options/types.py

@@ -14,12 +14,14 @@ option_names = (  # {{{
  'added_margin_bg',
  'background',
  'diff_cmd',
+ 'file_ignores',
  'filler_bg',
  'foreground',
  'highlight_added_bg',
  'highlight_removed_bg',
  'hunk_bg',
  'hunk_margin_bg',
+ 'ignore_paths',
  'map',
  'margin_bg',
  'margin_fg',
@@ -43,12 +45,14 @@ class Options:
     added_margin_bg: Color = Color(205, 255, 216)
     background: Color = Color(255, 255, 255)
     diff_cmd: str = 'auto'
+    file_ignores: typing.List[str] = ['']
     filler_bg: Color = Color(250, 251, 252)
     foreground: Color = Color(0, 0, 0)
     highlight_added_bg: Color = Color(172, 242, 189)
     highlight_removed_bg: Color = Color(253, 184, 192)
     hunk_bg: Color = Color(241, 248, 255)
     hunk_margin_bg: Color = Color(219, 237, 255)
+    ignore_paths: typing.List[str] = ['']
     margin_bg: Color = Color(250, 251, 252)
     margin_fg: Color = Color(170, 170, 170)
     margin_filler_bg: typing.Optional[kitty.fast_data_types.Color] = None

kittens/diff/options/utils.py

@@ -3,7 +3,7 @@
 # License: GPLv3 Copyright: 2021, Kovid Goyal <kovid at kovidgoyal.net>
 
 
-from typing import Any, Dict, Iterable, Tuple, Union
+from typing import Any, Dict, Iterable, List, Tuple, Union
 
 from kitty.conf.utils import (
     KeyFuncWrapper, KittensKeyDefinition, parse_kittens_key
@@ -58,6 +58,10 @@ def syntax_aliases(raw: str) -> Dict[str, str]:
     return ans
 
 
+def pattern_list(raw: str) -> List[str]:
+    return [pat for pat in raw.split(' ') if pat]
+
+
 def parse_map(val: str) -> Iterable[KittensKeyDefinition]:
     x = parse_kittens_key(val, func_with_args.args_funcs)
     if x is not None: