Split CSV Row Into Fields

Summary

Parse a single CSV row into its constituent fields handling quoted fields and escaped quotes.

Problem statement

CSV rows contain fields separated by commas. Fields may be enclosed in double quotes to include commas or leading/trailing spaces. Inside a quoted field, a double quote is represented by two consecutive double quotes. Implement split_csv_row(row) that returns a list of field strings following these rules: - Fields are separated by commas unless inside double quotes. - If a field is quoted, remove the surrounding quotes and unescape doubled quotes ("" -> "). - Trim leading and trailing spaces for unquoted fields, but preserve spaces inside quoted fields. - Empty fields (between consecutive commas) are allowed and should be returned as empty strings. Do not use Python's csv module; implement parsing using loops and string operations.

Task

Write a function that splits a CSV row string into a list of field strings, handling quoted fields (with commas inside) and double-quote escaping.

Examples

Input format

A single argument: row (string) representing one CSV row.

Output format

A list of strings representing the parsed fields.

Constraints

Row length <= 1000 characters. Do not use the csv module. Assume fields use double quotes for quoting and double-quote escaping.

Samples