date_format_parser

Link: https://crates.io/crates/date_format_parser

Date Format Parser project is designed to parse date and date-time strings into a standard ISO 8601 format. It supports multiple date formats, optional time components, and flexible separators.

Features

• Parse dates and date-times in multiple formats:
  • Year-Month-Day (e.g., 2000-12-20).
  • Day-Month-Year (e.g., 20.12.2000).
  • Month-Day-Year (e.g., 12/20/2000).
• Support for optional time components:
  • Time in 24-hour format (e.g., 14:30:45.123).
  • Time with optional seconds and milliseconds.
• Handles common separators:
  • Dashes (-), slashes (/), and dots (.).
• Outputs parsed results in ISO 8601 format:
  • Dates: YYYY-MM-DD
  • Date-times: YYYY-MM-DDTHH:MM:SS[.sss]
• User-friendly CLI interface with commands for:
  • Parsing input.
  • Displaying help information.
  • Showing credits.

Usage

Running the CLI

cargo run -- <input>

Replace <input> with a date or date-time string.

Commands

1. Help

cargo -- --help

Displays usage information.

2. Credits:

cargo run -- --credits

Shows project credits.

3. Parsing a Date or Date-Time:

cargo run -- "2000/12/20 14:30:45.123"

Parses the given input and outputs the result in ISO 8601 format:

"2000-12-20T14:30:45.123"

Supported Input Formats

Date Formats

1. Year-Month-Day:

• Example: 2000-12-20
• Separator: "-"

2. Day-Month-Year:

• Example: 20.12.2000
• Separator: "."

3. Month-Day-Year:

• Example: 12/20/2000
• Separator: "/"

Time Formats

1. 24-hour time:

• HH:MM:SS[.sss]
• Example: 14:30:45.123

2. Optional components:

• Without seconds: HH:MM
• Without milliseconds: HH:MM:SS

Combined Date-Time

Dates can optionally include times, separated by space:

• Example: 2000-12-20 14:30:45.123

Parsing Process (Technical Description)

The parsing process is built on a robust Pest grammar defined in grammar.pest. Here’s how the tool parses the input:

Input Validation

The input string is validated against a custom grammar defined in the Pest library. The grammar supports:

• Date components (year, month, day).
• Time components (hour, minute, second, millisecond).
• Flexible separators (-, /, .).

Grammar

The grammar uses rules to define valid date and time formats:

date_time = { date ~ (space ~ time)? }

date = { year_month_day | day_month_year | month_day_year }

year_month_day = { year ~ separator ~ month ~ separator ~ day }
day_month_year = { day ~ separator ~ month ~ separator ~ year }
month_day_year = { month ~ separator ~ day ~ separator ~ year }

year = { '1'..'9' ~ ASCII_DIGIT ~ ASCII_DIGIT ~ ASCII_DIGIT }
month = { ("0" ~ '1'..'9') | ("1" ~ '0'..'2') }
day = { ("0" ~ '1'..'9') | ('1'..'2' ~ ASCII_DIGIT) | ("3" ~ '0'..'1') }

time = { hour_24 ~ ":" ~ minute ~ (":" ~ second ~ ("." ~ millisecond)?)? }

hour_24 = { "0" ~ ASCII_DIGIT | "1" ~ ASCII_DIGIT | "2" ~ ('0'..'3') }

minute = { ('0'..'5' ~ ASCII_DIGIT) }
second = { ('0'..'5' ~ ASCII_DIGIT) }
millisecond = { ASCII_DIGIT ~ ASCII_DIGIT ~ ASCII_DIGIT }

separator = { "-" | "/" | "." }
space = { " " }

1. Top-Level Rule (date_time):
   • Parses a date.
   • Optionally parses time if preceded by a single space.
2. Date Formats:
   • year_month_day: Matches YYYY-MM-DD.
   • day_month_year: Matches DD.MM.YYYY.
   • month_day_year: Matches MM/DD/YYYY.
3. Time Formats:
   • Matches time in 24-hour format.
   • Handles optional seconds and milliseconds.
4. Separators and Spaces:
   • Dashes (-), slashes (/), dots (.), and spaces are supported.

Parsing Logic

1. The input string is parsed into components (date and time if present) using the Pest library.
2. The components are validated against the grammar and extracted:
   • Year, month, and day for dates.
   • Hour, minute, second, and millisecond for times.
3. The components are assembled into an ISO 8601 formatted string.

Use Cases

1. Standardizing Dates and Times:
   • Convert diverse date-time formats into a unified ISO 8601 format.
2. Data Cleaning:
   • Pre-process date-time data from files for further analysis.
3. Log Parsing:
   • Normalize timestamps in application logs for consistent formatting.

License

This project is licensed under the MIT License.