Parser combinators are great until you need to parse something real, like CSV with embedded newlines and Excel quotes. That’s when you reach for the reliable trio: awk, duct tape, and prayer.
replies(2):
Parser combinators are great until you need to parse something real, like CSV with embedded newlines and Excel quotes. That’s when you reach for the reliable trio: awk, duct tape, and prayer.
I don't follow why parser combinators would be a bad tool for CSV. It seems like one would specify a CSV parser as (pardon the pseudocode):
separator = ','
quote = '"'
quoted_quote = '""'
newline = '\n'
plain_field = sequence(char_except(either(separator, quote, newline)))
quoted_field = quote + sequence(either(char_except(quote), quoted_quote)) + quote
field = either(quoted_field, plain_field)
row = sequence_with_separator(field, separator)
csv = sequence_with_separator(row, newline)
Seems fairly natural to me, although I'll readily admit I haven't had to write a CSV parser before so I'm surely glossing over some detail.
Ah, you've clearly never had to parse a CSV exported from a municipal parking database in 2004. Quoted fields inside quoted fields, carriage returns mid-name, and a column that just says "ERROR" every 37th row. Your pseudocode would flee the scene.