1from __future__ import annotations
2
3from typing import TYPE_CHECKING, Iterable, List, TypeVar, cast, overload
4
5from prompt_toolkit.formatted_text.base import OneStyleAndTextTuple
6
7if TYPE_CHECKING:
8 from typing_extensions import SupportsIndex
9
10__all__ = [
11 "explode_text_fragments",
12]
13
14_T = TypeVar("_T", bound=OneStyleAndTextTuple)
15
16
17class _ExplodedList(List[_T]):
18 """
19 Wrapper around a list, that marks it as 'exploded'.
20
21 As soon as items are added or the list is extended, the new items are
22 automatically exploded as well.
23 """
24
25 exploded = True
26
27 def append(self, item: _T) -> None:
28 self.extend([item])
29
30 def extend(self, lst: Iterable[_T]) -> None:
31 super().extend(explode_text_fragments(lst))
32
33 def insert(self, index: SupportsIndex, item: _T) -> None:
34 raise NotImplementedError # TODO
35
36 # TODO: When creating a copy() or [:], return also an _ExplodedList.
37
38 @overload
39 def __setitem__(self, index: SupportsIndex, value: _T) -> None: ...
40
41 @overload
42 def __setitem__(self, index: slice, value: Iterable[_T]) -> None: ...
43
44 def __setitem__(
45 self, index: SupportsIndex | slice, value: _T | Iterable[_T]
46 ) -> None:
47 """
48 Ensure that when `(style_str, 'long string')` is set, the string will be
49 exploded.
50 """
51 if not isinstance(index, slice):
52 int_index = index.__index__()
53 index = slice(int_index, int_index + 1)
54 if isinstance(value, tuple): # In case of `OneStyleAndTextTuple`.
55 value = cast("List[_T]", [value])
56
57 super().__setitem__(index, explode_text_fragments(value))
58
59
60def explode_text_fragments(fragments: Iterable[_T]) -> _ExplodedList[_T]:
61 """
62 Turn a list of (style_str, text) tuples into another list where each string is
63 exactly one character.
64
65 It should be fine to call this function several times. Calling this on a
66 list that is already exploded, is a null operation.
67
68 :param fragments: List of (style, text) tuples.
69 """
70 # When the fragments is already exploded, don't explode again.
71 if isinstance(fragments, _ExplodedList):
72 return fragments
73
74 result: list[_T] = []
75
76 for style, string, *rest in fragments:
77 for c in string:
78 result.append((style, c, *rest)) # type: ignore
79
80 return _ExplodedList(result)