prompt-toolkit / prompt-toolkit/python-prompt-toolkit

How can I express `add value [value ...]` in a grammar compile?

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Description

Hi, I want to write a grammar like add value [value ...], for example:

add 1 2 3
add 1 2
add 10 11 12 13

All should be valid grammar.

Is it possible to do this in prompt_toolkit.contrib.regular_languages.compiler.compile? I tried everything but I can't figure it out. I tried with the grammar (\s* (?P<operator1>add) (\s+(?P<var1>[0-9.]+))+ \s*)

Here is the example I tried:

from prompt_toolkit import prompt
from prompt_toolkit.completion import WordCompleter
from prompt_toolkit.contrib.regular_languages.compiler import compile
from prompt_toolkit.contrib.regular_languages.completion import (
    GrammarCompleter,
)
from prompt_toolkit.contrib.regular_languages.lexer import GrammarLexer
from prompt_toolkit.lexers import SimpleLexer
from prompt_toolkit.styles import Style

operators1 = ['add']


def create_grammar():
    return compile(r"""
        (\s*  (?P<operator1>add)   (\s+(?P<var1>[0-9.]+))+    \s*)
    """)


example_style = Style.from_dict({
    'operator':       '#33aa33 bold',
    'number':         '#ff0000 bold',

    'trailing-input': 'bg:#662222 #ffffff',
})


if __name__ == '__main__':
    g = create_grammar()

    lexer = GrammarLexer(g, lexers={
        'operator1': SimpleLexer('class:operator'),
        'var1': SimpleLexer('class:number'),
    })

    completer = GrammarCompleter(g, {
        'operator1': WordCompleter(operators1),
    })

    # REPL loop.
    while True:
        # Read input and parse the result.
        text = prompt('Calculate: ', lexer=lexer, completer=completer,
                      style=example_style)
        m = g.match(text)
        if m:
            vars = m.variables()
        else:
            print('Invalid command\n')
            continue

        print(vars)

It seems that it can only recognize the last var1:

image

Many thanks.

@jonathanslenders

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  3. Fork the repository and make your change on a branch.
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Research direction

Start with prompt_toolkit.contrib.regular_languages.compiler.compile and trace how repeated named groups are represented by the match result. Then inspect GrammarLexer and GrammarCompleter to determine whether repeated values are supported consistently; done means commands with two or more numeric values are accepted and all values remain available.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
cli
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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