RealTest Script Validator - Standalone Package

Validate RealTest .rts script files using the RealTest Lark grammar.

What's Included

• validate_rts.py - Standalone validator script
• realtest.lark - Complete RealTest language grammar
• example_strategy.rts - Sample RealTest script for testing
• README.md - This file

Requirements

Python 3.7+ with one package:

pip install lark

That's it! No other dependencies.

Quick Start

Validate Single File

python validate_rts.py --file example_strategy.rts

Validate Directory of Scripts

python validate_rts.py --samples path/to/scripts/

Custom Grammar Path

python validate_rts.py --file script.rts --grammar path/to/realtest.lark

Usage

python validate_rts.py [OPTIONS]

Options:
  --file FILE          Validate specific .rts file
  --grammar GRAMMAR    Path to grammar file (default: realtest.lark)
  --samples SAMPLES    Path to samples directory (default: samples)

Examples

Validate single script:

python validate_rts.py --file my_strategy.rts

# Output:
# [OK] Grammar loaded successfully
# Found 1 file to validate: my_strategy.rts
# [  1/1] my_strategy.rts                          [PASS]
# [SUCCESS] All files parsed successfully!

Validate directory:

python validate_rts.py --samples my_strategies/

# Output:
# [OK] Grammar loaded successfully
# Found 25 files to validate
# [  1/25] strategy1.rts                          [PASS]
# [  2/25] strategy2.rts                          [PASS]
# ...
# Total: 25, Successful: 23 (92.0%), Failed: 2 (8.0%)

With custom grammar:

python validate_rts.py \
  --file script.rts \
  --grammar /path/to/my_realtest.lark

What It Validates

The validator checks that your RealTest script:

• ✅ Has valid syntax according to the grammar
• ✅ All sections (Import, Settings, Data, Strategy, etc.) are properly formatted
• ✅ Expressions, identifiers, and operators follow RealTest rules
• ✅ Comments are correctly placed
• ✅ String literals, numbers, and symbols are valid

What It Doesn't Check

This is grammar validation only. It doesn't check:

• ❌ Whether variable names conflict with functions (use semantic_validator.py)
• ❌ Whether data files exist
• ❌ Whether strategies make logical sense
• ❌ Whether parameters are in reasonable ranges

Exit Codes

• 0 - All files validated successfully
• 1 - One or more files failed validation or error occurred

Integration

Use in CI/CD pipelines:

# Validate before commit
python validate_rts.py --file strategies/my_strategy.rts || exit 1

# Validate all strategies
python validate_rts.py --samples strategies/ || exit 1

Grammar Details

The included realtest.lark grammar defines the complete RealTest Script Language including:

• Sections: Import, Settings, Data, Strategy, Parameters, etc.
• Expressions: Arithmetic, logical, comparisons, function calls
• Identifiers: Variables, symbols ($SPY), watchlists (&MyList), parameters (?pos)
• Literals: Numbers, strings, dates
• Operators: +, -, *, /, ^, and, or, not, >, <, =, etc.
• Functions: MA(), RSI(), ATR(), Extern(), etc.
• Comments: // single-line and /* multi-line */

Reporting Issues

🐛 Found a Validation Error?

If you have a .rts file that works correctly in RealTest but fails validation with this tool, please help us improve the grammar!

Report a Validation Error →

When reporting, please include:

• ✅ Your complete .rts file (or relevant sections)
• ✅ The full error message from the validator
• ✅ Confirmation that it works in RealTest (and which version)

Quick Tip: You can run the validator with --file to get detailed error output for a single file:

python validate_rts.py --file your_strategy.rts

✨ Have a Suggestion?

Want to suggest a grammar improvement or report another type of issue?

Browse Issue Templates →

Troubleshooting

"Grammar file not found"

Ensure realtest.lark is in the same directory as validate_rts.py, or use:

python validate_rts.py --grammar path/to/realtest.lark

"No module named 'lark'"

Install Lark:

pip install lark

Parse Errors

If validation fails, the error message shows:

• Line and column number
• What was expected vs what was found
• Context around the error

Example:

Error: Unexpected token Token('NEWLINE', '\n') at line 23, column 5
Expected one of: COLON

Fix the syntax error at the indicated line and re-run.

If you believe the error is incorrect (i.e., your file works in RealTest), please report it as a validation error!

Advanced Usage

Embedding in Your Own Tools

from validate_rts import load_grammar, validate_file
from pathlib import Path

# Load grammar once
parser = load_grammar('realtest.lark')

# Validate files
script = Path('my_strategy.rts')
success, error = validate_file(parser, script)

if success:
    print("Valid!")
else:
    print(f"Invalid: {error}")

Batch Validation

from pathlib import Path
from validate_rts import load_grammar, validate_file

parser = load_grammar('realtest.lark')

for script in Path('strategies').glob('*.rts'):
    success, error = validate_file(parser, script)
    if not success:
        print(f"FAIL: {script.name} - {error}")

About RealTest

RealTest is a portfolio-level backtesting system for trading strategies. Learn more at the RealTest forum and documentation.

License

This validator is provided as-is for use with RealTest scripts. The grammar represents the RealTest Script Language syntax.

Version

Compatible with RealTest 2024+ syntax.

Last updated: November 2025