generator.py

from parsing import *
import samples


def get_grammar():
    return samples.get_sample_1()


def describe_grammar(gr):
    return '\n'.join([
        'Indexed grammar rules (%d in total):' % len(gr.productions),
        str(gr) + '\n',
        'Grammar non-terminals (%d in total):' % len(gr.nonterms),
        '\n'.join('\t' + str(s) for s in gr.nonterms) + '\n',
        'Grammar terminals (%d in total):' % len(gr.terminals),
        '\n'.join('\t' + str(s) for s in gr.terminals)
    ])


def describe_parsing_table(table):
    conflict_status = table.get_conflict_status()

    def conflict_status_str(state_id):
        has_sr_conflict = (conflict_status[state_id] == lalr_one.STATUS_SR_CONFLICT)
        status_str = ('shift-reduce' if has_sr_conflict else 'reduce-reduce')
        return 'State %d has a %s conflict' % (state_id, status_str)

    return ''.join([
        'PARSING TABLE SUMMARY\n',
        'Is the given grammar LALR(1)? %s\n' % ('Yes' if table.is_lalr_one() else 'No'),
        ''.join(conflict_status_str(sid) + '\n' for sid in range(table.n_states)
                if conflict_status[sid] != lalr_one.STATUS_OK) + '\n',
        table.stringify()
    ])


def main():
    print('Working on it...')
    gr = get_grammar()
    table = lalr_one.ParsingTable(gr)
    print("I'm done.")

    output_filename = 'parsing-table'

    with open(output_filename + '.txt', 'w') as textfile:
        textfile.write(describe_grammar(gr))
        textfile.write('\n\n')
        textfile.write(describe_parsing_table(table))

    table.save_to_csv(output_filename + '.csv')


if __name__ == "__main__":
    main()