time-parser

time-parser is a Rust command-line tool and library for parsing timestamped log lines. It automatically detects multiple timestamp formats and converts logs into structured data.

This project was created as a parsing assignment and demonstrates:

• Manual parsing without external parsing frameworks
• Grammar rule design
• Error handling with thiserror and anyhow
• Full CLI + library separation
• Automated testing and formatting

🧠 Supported Timestamp Formats

The parser automatically detects and supports three formats:

| ISO | 2024-03-15 12:00:00 | | European | 15-03-2024 12:00:00 | | American | 03-15-2024 12:00:00 |

Detection logic:

1. Try ISO format first (YYYY-MM-DD)
2. If that fails:
   • If first number > 12 → European (DD-MM-YYYY)
   • If second number > 12 → American (MM-DD-YYYY)
   • If both ≤ 12 → default to European
3. If all fail → error

📜 Log Format Overview

Each log line must follow this structure:

TIMESTAMP [KIND] MESSAGE METADATA

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Example:

15-03-2024 10:00:00 [INFO] Server started user=alice id=42

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📏 Grammar Rules

Formal grammar (EBNF-style):

LOG = TIMESTAMP " [" KIND "] " MESSAGE (" " METADATA)? TIMESTAMP = ISO | EU | US ISO = YYYY "-" MM "-" DD " " HH ":" MM ":" SS EU = DD "-" MM "-" YYYY " " HH ":" MM ":" SS US = MM "-" DD "-" YYYY " " HH ":" MM ":" SS

KIND = uppercase_text MESSAGE = text until metadata starts METADATA = KVPAIR ( " " KVPAIR )* KVPAIR = KEY "=" VALUE

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⚙️ How the Parser Works

1. Timestamp parser

   • Detects format
   • Converts into chrono::NaiveDateTime

2. Kind parser

   • Reads [INFO], [WARN], [ERROR] etc.

3. Message parser

   • Consumes text until a key=value token appears

4. Metadata parser

   • Splits key=value pairs
   • Converts them into a HashMap<String, String>

5. Final output Each line becomes this Rust struct:

pub struct Entry {
    pub timestamp: NaiveDateTime,
    pub kind: String,
    pub message: String,
    pub metadata: HashMap<String, String>,
}
💻 CLI Usage
Parse a file:

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time-parser parse logs.txt
Show credits:

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time-parser credits
Show help:

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time-parser --help
Output example:

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{
  "timestamp": "2024-03-15 10:00:00",
  "kind": "INFO",
  "message": "Server started",
  "metadata": {
    "user": "alice",
    "id": "42"
  }
}