Add option select_by_word_characters_forward

This adds an option to select separate characters for forward and
backward word extension on double click. If it is empty the old behavior
is preserved. This is the default.

If it is not empty, select_by_word_characters_forward will be used for
extending the selection in forward direction (right) and
select_by_word_characters will be used for extending in backward
direction (left).

Signed-off-by: Konrad Gräfe <kgraefe@paktolos.net>

kitty/options/definition.py

@@ -492,6 +492,18 @@ Unicode database will be matched.
 '''
     )
 
+opt('select_by_word_characters_forward', '',
+    ctype='!select_by_word_characters_forward',
+    long_text='''
+Characters considered part of a word when extending the selection forward on
+double clicking. In addition to these characters any character that is marked
+as an alphanumeric character in the Unicode database will be matched.
+
+If empty (default) :opt:`select_by_word_characters` will be used for both
+directions.
+'''
+    )
+
 opt('click_interval', '-1.0',
     option_type='float', ctype='time',
     long_text='''

kitty/options/parse.py

@@ -1163,6 +1163,9 @@ class Parser:
     def select_by_word_characters(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['select_by_word_characters'] = str(val)
 
+    def select_by_word_characters_forward(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
+        ans['select_by_word_characters_forward'] = str(val)
+
     def selection_background(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['selection_background'] = to_color_or_none(val)
 

kitty/options/to-c-generated.h

@@ -304,6 +304,19 @@ convert_from_opts_select_by_word_characters(PyObject *py_opts, Options *opts) {
     Py_DECREF(ret);
 }
 
+static void
+convert_from_python_select_by_word_characters_forward(PyObject *val, Options *opts) {
+    select_by_word_characters_forward(val, opts);
+}
+
+static void
+convert_from_opts_select_by_word_characters_forward(PyObject *py_opts, Options *opts) {
+    PyObject *ret = PyObject_GetAttrString(py_opts, "select_by_word_characters_forward");
+    if (ret == NULL) return;
+    convert_from_python_select_by_word_characters_forward(ret, opts);
+    Py_DECREF(ret);
+}
+
 static void
 convert_from_python_click_interval(PyObject *val, Options *opts) {
     opts->click_interval = parse_s_double_to_monotonic_t(val);
@@ -1067,6 +1080,8 @@ convert_opts_from_python_opts(PyObject *py_opts, Options *opts) {
     if (PyErr_Occurred()) return false;
     convert_from_opts_select_by_word_characters(py_opts, opts);
     if (PyErr_Occurred()) return false;
+    convert_from_opts_select_by_word_characters_forward(py_opts, opts);
+    if (PyErr_Occurred()) return false;
     convert_from_opts_click_interval(py_opts, opts);
     if (PyErr_Occurred()) return false;
     convert_from_opts_focus_follows_mouse(py_opts, opts);

kitty/options/to-c.h

@@ -187,6 +187,12 @@ select_by_word_characters(PyObject *chars, Options *opts) {
     opts->select_by_word_characters = list_of_chars(chars);
 }
 
+static void
+select_by_word_characters_forward(PyObject *chars, Options *opts) {
+    free(opts->select_by_word_characters_forward);
+    opts->select_by_word_characters_forward = list_of_chars(chars);
+}
+
 static void
 tab_bar_style(PyObject *val, Options *opts) {
     opts->tab_bar_hidden = PyUnicode_CompareWithASCIIString(val, "hidden") == 0 ? true: false;

kitty/options/types.py

@@ -411,6 +411,7 @@ option_names = (  # {{{
  'scrollback_pager',
  'scrollback_pager_history_size',
  'select_by_word_characters',
+ 'select_by_word_characters_forward',
  'selection_background',
  'selection_foreground',
  'shell',
@@ -561,6 +562,7 @@ class Options:
     scrollback_pager: typing.List[str] = ['less', '--chop-long-lines', '--RAW-CONTROL-CHARS', '+INPUT_LINE_NUMBER']
     scrollback_pager_history_size: int = 0
     select_by_word_characters: str = '@-./_~?&=%+#'
+    select_by_word_characters_forward: str = ''
     selection_background: typing.Optional[kitty.fast_data_types.Color] = Color(255, 250, 205)
     selection_foreground: typing.Optional[kitty.fast_data_types.Color] = Color(0, 0, 0)
     shell: str = '.'

kitty/screen.c

@@ -3222,7 +3222,15 @@ screen_selection_range_for_line(Screen *self, index_type y, index_type *start, i
 }
 
 static bool
-is_opt_word_char(char_type ch) {
+is_opt_word_char(char_type ch, bool forward) {
+    if (forward && OPT(select_by_word_characters_forward)) {
+        for (const char_type *p = OPT(select_by_word_characters_forward); *p; p++) {
+            if (ch == *p) return true;
+        }
+        if (*OPT(select_by_word_characters_forward)) {
+            return false;
+        }
+    }
     if (OPT(select_by_word_characters)) {
         for (const char_type *p = OPT(select_by_word_characters); *p; p++) {
             if (ch == *p) return true;
@@ -3232,9 +3240,9 @@ is_opt_word_char(char_type ch) {
 }
 
 static bool
-is_char_ok_for_word_extension(Line* line, index_type x) {
+is_char_ok_for_word_extension(Line* line, index_type x, bool forward) {
     char_type ch = line->cpu_cells[x].ch;
-    if (is_word_char(ch) || is_opt_word_char(ch)) return true;
+    if (is_word_char(ch) || is_opt_word_char(ch, forward)) return true;
     // pass : from :// so that common URLs are matched
     if (ch == ':' && x + 2 < line->xnum && line->cpu_cells[x+1].ch == '/' && line->cpu_cells[x+2].ch == '/') return true;
     return false;
@@ -3247,26 +3255,26 @@ screen_selection_range_for_word(Screen *self, const index_type x, const index_ty
     Line *line = visual_line_(self, y);
     *y1 = y;
     *y2 = y;
-#define is_ok(x) is_char_ok_for_word_extension(line, x)
+#define is_ok(x, forward) is_char_ok_for_word_extension(line, x, forward)
-    if (!is_ok(x)) {
+    if (!is_ok(x, false)) {
         if (initial_selection) return false;
         *s = x; *e = x;
         return true;
     }
     start = x; end = x;
     while(true) {
-        while(start > 0 && is_ok(start - 1)) start--;
+        while(start > 0 && is_ok(start - 1, false)) start--;
         if (start > 0 || !line->attrs.continued || *y1 == 0) break;
         line = visual_line_(self, *y1 - 1);
-        if (!is_ok(self->columns - 1)) break;
+        if (!is_ok(self->columns - 1, false)) break;
         (*y1)--; start = self->columns - 1;
     }
     line = visual_line_(self, *y2);
     while(true) {
-        while(end < self->columns - 1 && is_ok(end + 1)) end++;
+        while(end < self->columns - 1 && is_ok(end + 1, true)) end++;
         if (end < self->columns - 1 || *y2 >= self->lines - 1) break;
         line = visual_line_(self, *y2 + 1);
-        if (!line->attrs.continued || !is_ok(0)) break;
+        if (!line->attrs.continued || !is_ok(0, true)) break;
         (*y2)++; end = 0;
     }
     *s = start; *e = end;

kitty/state.h

@@ -33,6 +33,7 @@ typedef struct {
     unsigned int scrollback_pager_history_size;
     bool scrollback_fill_enlarged_window;
     char_type *select_by_word_characters;
+    char_type *select_by_word_characters_forward;
     color_type url_color, background, foreground, active_border_color, inactive_border_color, bell_border_color, tab_bar_background, tab_bar_margin_color;
     color_type mark1_foreground, mark1_background, mark2_foreground, mark2_background, mark3_foreground, mark3_background;
     monotonic_t repaint_delay, input_delay;