lalr1_parser Namespace Reference

Classes
class	LALR1Parser

Functions
	describe_grammar (gr)
	describe_parsing_table (table)
	get_grammar (parser)
	main ()

Detailed Description

 * @file lalr1_parse_table_generator.py
 * @author M.H. Gholamrezei (mh@hyperdbg.org)
 * @brief Script engine LALR(1) Parse table generator 
 * @details This program reads grammar from Boolean_Expression_Grammar.txt file 
 *          placed in the same directory of the program 
 *          and creates parse_table.h and parse_table.c which is 
 *          used by the parser of script engine. 
 * @version 0.1
 * @date 2021-02-07
 *
 * @copyright This project is released under the GNU Public License v3.

Function Documentation

describe_grammar()

lalr1_parser.describe_grammar

(

gr

)

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)
    ])
 
 

describe_parsing_table()

lalr1_parser.describe_parsing_table

(

table

)

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()
    ])
 

get_grammar()

lalr1_parser.get_grammar

(

parser

)

def get_grammar(parser):
    Rules = []
    i = 0
    preLhs = parser.LhsList[0]
    RhsList = []
    for Lhs in parser.LhsList:
        Rhs = ""
 
        for X in parser.RhsList[i]:
            if parser.IsNoneTerminal(X):
                Rhs += X
            elif parser.IsSemanticRule(X):
                continue
            else:
                Rhs += ("'" + X + "'")
            Rhs += " "
        if parser.RhsList[i][0] == 'eps':
            Rhs = ""
 
        if preLhs != Lhs:
            Rules.append(NonTerminal(preLhs, RhsList))
            RhsList = []
 
 
        RhsList.append(Rhs)
       
        i = i + 1
        preLhs = Lhs
 
    Rules.append(NonTerminal(preLhs, RhsList))
    
    return Grammar(Rules)
 
 

main()

lalr1_parser.main

(

)

def main():
    print('Working on it...')
    parser = LALR1Parser()
    parser.Run()
    gr = get_grammar(parser)
    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')
    parser.Parse(table, ['(', '_hex', '&', 'id', '>', 'id', ')', '&', '(', 'id', '<', 'id',')', '$end'])