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##############################################################################
# Name: csv.py
# Purpose: Implementation of CSV parser in arpeggio.
# Author: Igor R. Dejanovic <igor DOT dejanovic AT gmail DOT com>
# Copyright: (c) 2014-2015 Igor R. Dejanovic <igor DOT dejanovic AT gmail DOT com>
# License: MIT License
##############################################################################
import os
import pprint
from arpeggio import visit_parse_tree
from arpeggio.cleanpeg import ParserPEG
from examples.csv.csv import CSVVisitor
def main(debug=False):
# First we will make a parser - an instance of the CVS parser model.
# Parser model is given in the form of clean PEG description therefore we
# are using ParserPEG class from arpeggio.clenapeg. Grammar is loaded from
# csv.peg file Skipping of whitespace will be done only for tabs and
# spaces. Newlines have semantics in csv files. They are used to separate
# records.
current_dir = os.path.dirname(__file__)
csv_grammar = open(os.path.join(current_dir, 'csv.peg'), 'r').read()
parser = ParserPEG(csv_grammar, 'csvfile', ws='\t ', debug=debug)
# Creating parse tree out of textual input
test_data = open(os.path.join(current_dir, 'test_data.csv'), 'r').read()
parse_tree = parser.parse(test_data)
# Create list of lists using visitor
csv_content = visit_parse_tree(parse_tree, CSVVisitor())
print("This is a list of lists with the data from CSV file.")
pp = pprint.PrettyPrinter(indent=4)
pp.pprint(csv_content)
if __name__ == "__main__":
# In debug mode dot (graphviz) files for parser model
# and parse tree will be created for visualization.
# Checkout current folder for .dot files.
main(debug=True)
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