Englishish generator

englishish.py

#!/usr/bin/env python3

"""
englishish.py is a quick-and-dirty prototype of a project I plan to work on
more later: A generator for text which obeys English spelling and grammar
rules, but whose output is nonsensical. The output of this script does tend
to make sense, but that's a product of the dictionary. If it was larger, it
would generate sentences which are grammatical but not sensical.

The next step is implementing this with a bigger dictionary, cleaner code, and
probably in Rust as a C-compatible library. I plan to use it in a little art
game about Borges' Library of Babel -- to generate the contents of the books.

Once it's implemented in Rust, it'll probably be FOSS'd as a separate repo.
"""

from collections import namedtuple
import random


def det_a_an(next):
    # not ideal but close enough
    if next[0] in 'aeiou':
        return 'an'
    else:
        return 'a'


def det_thy_thine(next):
    if next[0] in 'aeiou':
        return 'thine'
    else:
        return 'thy'


TERMINALS = {
    'article': ['the', det_a_an],
    'of': ['of'],
    'conjunction': ['and', 'or'],

    'adverb': ['widely', 'angrily', 'cutely', 'really'],

    'adjective': ['wide', 'angry', 'cute'],

    '1.nom.noun': ['cat', 'dog', 'keyboard', 'otter'],
    'M.nom.noun': ['cats', 'dogs', 'keyboards', 'otters'],
    '1.pos.noun': ["cat's", "dog's", "keyboard's", "otter's"],
    'M.pos.noun': ["cats'", "dogs'", "keyboards'", "otters'"],

    '1.nom.pron': ['I', 'thou', 'he', 'she', 'they'],
    'M.nom.pron': ['we', "y'all", 'they'],
    'pos.pron': [
        # singular
        'my', det_thy_thine, 'his', 'her', 'their',
        # plural
        'our', "y'all's", 'their'
    ],

    'M.verb': ['like', 'hug', 'poke'],
    '1.verb': ['likes', 'hugs', 'pokes'],
}

OPTIONS = {
    'sentence': [
        (3, ['1.noun-phrase', '1.verb-phrase', '1.noun-phrase']),
        (1, ['M.noun-phrase', 'M.verb-phrase', '1.noun-phrase']),
        (3, ['1.noun-phrase', '1.verb-phrase', 'M.noun-phrase']),
        (1, ['M.noun-phrase', 'M.verb-phrase', 'M.noun-phrase']),
    ],
    '1.noun-phrase': [
        (3, ['article', '1.described-noun']),
        (1, ['pos.pron', '1.described-noun']),
    ],
    '1.described-noun': [
        (8, ['1.nom.noun']),
        (3, ['adjective', '1.nom.noun']),
        (2, ['1.pos.noun', '1.nom.noun']),
        (1, ['M.pos.noun', '1.nom.noun']),
        (1, ['adverb', 'adjective', '1.described-noun']),
    ],
    'M.noun-phrase': [
        (3, ['article', 'M.described-noun']),
        (1, ['pos.pron', 'M.described-noun']),
        (3, ['M.described-noun']),
    ],
    'M.described-noun': [
        (16, ['M.nom.noun']),
        (6, ['adjective', 'M.nom.noun']),
        (4, ['1.pos.noun', 'M.nom.noun']),
        (4, ['M.pos.noun', 'M.nom.noun']),
        (2, ['adverb', 'M.described-noun']),
        (1, ['1.noun-phrase', 'conjunction', '1.noun-phrase']),
        (1, ['M.noun-phrase', 'conjunction', '1.noun-phrase']),
        (1, ['1.noun-phrase', 'conjunction', 'M.noun-phrase']),
        (1, ['M.noun-phrase', 'conjunction', 'M.noun-phrase']),
    ],
    '1.verb-phrase': [
        (4, ['1.verb']),
        (1, ['adverb', '1.verb-phrase']),
    ],
    'M.verb-phrase': [
        (4, ['M.verb']),
        (1, ['adverb', 'M.verb-phrase']),
    ],
}


def weighted_choose_child(name):
    children = OPTIONS[name]
    total_odds = sum(weight for weight, _ in children)
    spot = random.randrange(total_odds)
    for weight, components in children:
        if spot < weight:
            return components
        else:
            spot -= weight
    else:
        raise ValueError("what")


def expand_options(root):
    res = []
    stack = [root]
    while stack:
        top = stack.pop()
        if top in TERMINALS:
            res.append(top)
        else:
            nexts = weighted_choose_child(top)
            stack.extend(nexts[::-1])
    return res


def generate(terminals):
    words = []
    for term in terminals[::-1]:
        val = random.choice(TERMINALS[term])
        if isinstance(val, str):
            words.insert(0, val)
        elif hasattr(val, '__call__'):
            words.insert(0, val(words[0]))
        else:
            raise ValueError("fucc")
    return ' '.join(words)


if __name__ == '__main__':
    print(generate(expand_options('sentence')))