aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/prompt-toolkit/py2/prompt_toolkit/auto_suggest.py
blob: 5e5eb80ef1a042372125ea89c9ea4dc4b6c26c8d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
""" 
`Fish-style <http://fishshell.com/>`_  like auto-suggestion. 
 
While a user types input in a certain buffer, suggestions are generated 
(asynchronously.) Usually, they are displayed after the input. When the cursor 
presses the right arrow and the cursor is at the end of the input, the 
suggestion will be inserted. 
""" 
from __future__ import unicode_literals 
from abc import ABCMeta, abstractmethod 
from six import with_metaclass 
 
from .filters import to_cli_filter 
 
__all__ = ( 
    'Suggestion', 
    'AutoSuggest', 
    'AutoSuggestFromHistory', 
    'ConditionalAutoSuggest', 
) 
 
 
class Suggestion(object): 
    """ 
    Suggestion returned by an auto-suggest algorithm. 
 
    :param text: The suggestion text. 
    """ 
    def __init__(self, text): 
        self.text = text 
 
    def __repr__(self): 
        return 'Suggestion(%s)' % self.text 
 
 
class AutoSuggest(with_metaclass(ABCMeta, object)): 
    """ 
    Base class for auto suggestion implementations. 
    """ 
    @abstractmethod 
    def get_suggestion(self, cli, buffer, document): 
        """ 
        Return `None` or a :class:`.Suggestion` instance. 
 
        We receive both ``buffer`` and ``document``. The reason is that auto 
        suggestions are retrieved asynchronously. (Like completions.) The 
        buffer text could be changed in the meantime, but ``document`` contains 
        the buffer document like it was at the start of the auto suggestion 
        call. So, from here, don't access ``buffer.text``, but use 
        ``document.text`` instead. 
 
        :param buffer: The :class:`~prompt_toolkit.buffer.Buffer` instance. 
        :param document: The :class:`~prompt_toolkit.document.Document` instance. 
        """ 
 
 
class AutoSuggestFromHistory(AutoSuggest): 
    """ 
    Give suggestions based on the lines in the history. 
    """ 
    def get_suggestion(self, cli, buffer, document): 
        history = buffer.history 
 
        # Consider only the last line for the suggestion. 
        text = document.text.rsplit('\n', 1)[-1] 
 
        # Only create a suggestion when this is not an empty line. 
        if text.strip(): 
            # Find first matching line in history. 
            for string in reversed(list(history)): 
                for line in reversed(string.splitlines()): 
                    if line.startswith(text): 
                        return Suggestion(line[len(text):]) 
 
 
class ConditionalAutoSuggest(AutoSuggest): 
    """ 
    Auto suggest that can be turned on and of according to a certain condition. 
    """ 
    def __init__(self, auto_suggest, filter): 
        assert isinstance(auto_suggest, AutoSuggest) 
 
        self.auto_suggest = auto_suggest 
        self.filter = to_cli_filter(filter) 
 
    def get_suggestion(self, cli, buffer, document): 
        if self.filter(cli): 
            return self.auto_suggest.get_suggestion(cli, buffer, document)