diff kitten: Make the representation of tabs configurable

kittens/diff/config.py

@@ -6,7 +6,7 @@ import os
 
 from kitty.config_utils import (
     init_config, load_config as _load_config, merge_dicts, parse_config_base,
-    resolve_config, to_color
+    python_string, resolve_config, to_color
 )
 from kitty.constants import config_dir
 from kitty.rgb import color_as_sgr
@@ -50,6 +50,7 @@ def syntax_aliases(raw):
 type_map = {
     'syntax_aliases': syntax_aliases,
     'num_context_lines': int,
+    'replace_tab_by': python_string,
 }
 
 for name in (

kittens/diff/diff.conf

@@ -17,6 +17,9 @@ num_context_lines 3
 # is to search the system for either git or diff and use that, if found.
 diff_cmd auto
 
+# The string to replace tabs with. Default is to use four spaces.
+replace_tab_by \x20\x20\x20\x20
+
 # Colors
 foreground            black
 background            white

kittens/diff/main.py

@@ -19,7 +19,9 @@ from ..tui.handler import Handler
 from ..tui.images import ImageManager
 from ..tui.loop import Loop
 from ..tui.operations import styled
-from .collect import create_collection, data_for_path, set_highlight_data
+from .collect import (
+    create_collection, data_for_path, lines_for_path, set_highlight_data
+)
 from .config import init_config
 from .patch import Differ, set_diff_command
 from .render import ImageSupportWarning, LineRef, render_diff
@@ -397,6 +399,7 @@ def main(args):
         raise SystemExit('The items to be diffed should both be either directories or files. Comparing a directory to a file is not valid.')
     opts = init_config(args)
     set_diff_command(opts.diff_cmd)
+    lines_for_path.replace_tab_by = opts.replace_tab_by
 
     loop = Loop()
     handler = DiffHandler(args, opts, left, right)

kitty/config.py

@@ -2,7 +2,6 @@
 # vim:fileencoding=utf-8
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
-import ast
 import json
 import os
 import re
@@ -13,7 +12,8 @@ from contextlib import contextmanager
 from . import fast_data_types as defines
 from .config_utils import (
     init_config, load_config as _load_config, merge_dicts, parse_config_base,
-    positive_float, positive_int, to_bool, to_cmdline, to_color, unit_float
+    positive_float, positive_int, python_string, to_bool, to_cmdline, to_color,
+    unit_float
 )
 from .constants import cache_dir, defconf
 from .fast_data_types import CURSOR_BEAM, CURSOR_BLOCK, CURSOR_UNDERLINE
@@ -223,8 +223,7 @@ def parse_symbol_map(val):
 
 
 def parse_send_text_bytes(text):
-    return ast.literal_eval("'''" + text.replace("'''", "'\\''") + "'''"
-                            ).encode('utf-8')
+    return python_string(text).encode('utf-8')
 
 
 def parse_send_text(val, key_definitions):

kitty/config_utils.py

@@ -2,6 +2,7 @@
 # vim:fileencoding=utf-8
 # License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
 
+import ast
 import os
 import re
 import shlex
@@ -38,6 +39,10 @@ def to_cmdline(x):
     return ans
 
 
+def python_string(text):
+    return ast.literal_eval("'''" + text.replace("'''", "'\\''") + "'''")
+
+
 def parse_line(line, type_map, special_handling, ans, all_keys, base_path_for_includes):
     line = line.strip()
     if not line or line.startswith('#'):