Rule File Language Extension

A comprehensive VS Code extension providing advanced syntax highlighting, intelligent navigation, sophisticated language features, multi-level syntax validation, and bidirectional Python integration for rule files (.rul). Features include precision column alignment validation, comprehensive duplicate detection, context-aware invalid syntax detection, and seamless cross-language navigation between .rul and Python files.

Features

🎨 Syntax Highlighting

Parameter headers (PRODUCT_ID?) - Highlighted in blue/cyan
Variable headers (BATCH_ID:) - Highlighted in purple/magenta
Keywords, operators, numbers, booleans, strings
Comments (both # line comments and /* */ block comments)
Special values (NULL, NA, *)
List structures with proper bracket highlighting
Complex expressions (100*int(MULTIPLIER)) - Recognized as single values
Nested objects ({'config':[{0:0}]}) - Properly highlighted and structured

Go to Definition (F12) - Jump between parameter and variable headers
Find All References (Shift+F12) - Find all usages of identifiers across .rul and Python files ✨
Rename Symbol (F2) - Rename parameters/variables across the file
Hover tooltips - Show usage statistics including Python reference counts ✨
Cross-file navigation - Find definitions and references across multiple rule files in workspace
Bidirectional Python integration - Navigate seamlessly between .rul and Python files ✨

🔗 Python Integration

Bidirectional Cross-Language Navigation - Navigate seamlessly between Python and .rul files:

Python → .rul (Go to Definition)

Smart Navigation: Ctrl+Click on rules.VARIABLE_NAME jumps to .rul file definition
Multi-Format Support: Finds variables in table headers, assignments, and requirements
Workspace-Wide: Searches all .rul files in your workspace

.rul → Python (Find References) ✨ NEW

Reverse Cross-Reference: Right-click on any variable in .rul files and see Python usage
Enhanced Find All References: Shows both .rul and Python references in one view
Python Pattern Detection: Finds rules.VARIABLE_NAME and rule_mgr.attributes['VARIABLE_NAME']
Smart Hover Tooltips: Shows Python reference counts when hovering over variables

Usage Examples:

Python to .rul Navigation:

# example.py
from rule_mgr.attributes import rules

def calculate_limits():
    temp = rules.TEMP_LIMIT        # Ctrl+Click → jumps to TEMP_LIMIT: in .rul file
    if rules.ENABLE_FEATURE:       # Ctrl+Click → jumps to ENABLE_FEATURE: definition
        return rules.MAX_VALUE     # Navigation works for all rule variables

Reverse Navigation (.rul to Python):

# config.rul
STAGE1:  STAGE2:  HIGH_TEMP:   LOW_TEMP:   TEST_A:  FINAL_TEST:     STEP_SELECT?
--------------------------------------------------------------------------------
False    False    False        False       False    True            ['FINAL_TEST']

Right-click on FINAL_TEST: → "Find All References" shows:

✅ All .rul file references (headers, assignments, usage)
✅ All Python file references (rules.FINAL_TEST, rule_mgr.attributes['FINAL_TEST'])

Enhanced Hover Information:

FINAL_TEST:    # Hover shows: "• 3 parameter usage(s) • 1 variable assignment(s) • 12 Python reference(s)"

Supported Python Patterns:

rules.VARIABLE_NAME - Direct rule access
rule_mgr.attributes['VARIABLE_NAME'] - Dictionary-style access (single quotes)
rule_mgr.attributes["VARIABLE_NAME"] - Dictionary-style access (double quotes)

Note: This feature provides additional .rul file definitions alongside VS Code's built-in Python navigation.

🔍 Advanced Syntax Validation

The extension provides three levels of intelligent syntax checking:

1. Column Alignment Validation

Super-sensitive alignment detection that catches even single-character misalignments:

✅ Detects column shifts and spacing inconsistencies
✅ Handles complex expressions as single values
✅ Ignores formatting symbols in alignment calculations
⚙️ Configurable: Adjust tolerance levels or disable entirely

2. Duplicate Detection

Comprehensive duplicate variable/header detection across all formats:

Parameter duplicates: Multiple VARIABLE? definitions
Assignment duplicates: Multiple VARIABLE: assignments
Assignment operator duplicates: Multiple VARIABLE = value statements
Cross-format duplicates: Mixed usage of ?, :, and = for same variable
⚙️ Configurable: Enable/disable duplicate checking

# Duplicate detection examples
PRODUCT_ID?    BATCH_ID?    UNIT_ID?
PRODUCT_ID?    SERIAL_ID?   UNIT_ID?    # ❌ PRODUCT_ID and UNIT_ID duplicated

VOLTAGE:      3.3V
VOLTAGE:      5.0V                # ❌ VOLTAGE duplicated

TEMP_LIMIT = 85
TEMP_LIMIT = 90                   # ❌ TEMP_LIMIT duplicated with = operator

3. Invalid Syntax Detection

Context-aware detection of undefined identifiers with smart exclusions:

Standalone identifiers: Variables referenced but never defined
Table headers: Column headers without parameter definitions
Smart filtering: Excludes table cell values and assignment expressions
Table structure awareness: Understands table context to prevent false positives
⚙️ Configurable: Enable/disable missing identifier checking

# Invalid syntax examples
UNDEFINED_VAR               # ❌ Standalone undefined identifier
MISSING_HEADER?   VALUE?   
ROW_DATA         42        # ❌ MISSING_HEADER defined but ROW_DATA not

# Smart exclusions (these are NOT flagged)
VOLTAGE: UNDEFINED_VALUE    # ✅ Part of assignment, not flagged
TABLE_DATA UNDEFINED_CELL   # ✅ Part of table data, not flagged

🎯 Column Alignment Features

Zero-tolerance alignment checking - Detects misalignments as small as one character
Smart value detection - Recognizes complex patterns:
- Mathematical expressions: 40e-6, 100*int(FUNCTION)
- Quoted arrays: ['OPTION_A'], ['MODE_A', 'MODE_B']
- Nested objects: {'mapping':[{0:0}]}
- Function calls: int(MULTIPLIER_VALUE)
Formatting symbol exclusion - Ignores standalone symbols like *, -, ], } when checking alignment
Error-level reporting - Column misalignments reported as errors for immediate attention

✨ Code Snippets

Type these prefixes and press Tab to expand:

param → Parameter header template
var → Variable header template
section → Header section with parameter and variable
bool → Boolean assignment
row → Table row with tab-separated values
comment → Comment block
region → Collapsible region markers

User Configuration

Customize the extension behavior through VS Code settings (Ctrl+, → Extensions → Rule File Language):

Alignment Validation Settings

{
  "rulefile.validation.enableColumnAlignment": true,
  "rulefile.validation.alignmentTolerance": 0
}

enableColumnAlignment: Enable/disable column alignment checking
alignmentTolerance: Number of characters tolerance for alignment (0 = zero tolerance)

Duplicate Detection Settings

{
  "rulefile.validation.enableDuplicateDetection": true
}

enableDuplicateDetection: Enable/disable detection of duplicate variable/parameter definitions

Invalid Syntax Detection Settings

{
  "rulefile.validation.enableInvalidSyntaxDetection": true
}

enableInvalidSyntaxDetection: Enable/disable detection of undefined identifiers and missing indicators (standalone variables not defined as parameters)

Python Cross-Reference Settings ✨ NEW

{
  "rulefile.python.enableCrossReference": true,
  "rulefile.python.enableReverseReference": true
}

enableCrossReference: Enable/disable Python → .rul "Go to Definition" functionality (Ctrl+Click on rules.VARIABLE_NAME)
enableReverseReference: Enable/disable .rul → Python "Find References" functionality and Python reference counts in hover tooltips

Configuration Tips:

Settings take effect immediately after changing (no restart required)
You can disable Python integration entirely by setting both options to false
Individual control: Keep cross-reference but disable reverse lookup, or vice versa
Useful for large workspaces where Python file scanning might impact performance

Note: All validation features are enabled by default except duplicate detection. Python cross-reference features are enabled by default. To disable any feature, set the corresponding setting to false in your VS Code settings.

Testing Configuration Changes

To verify your configuration changes are working:

Python → .rul Navigation:
- Disable: Set "rulefile.python.enableCrossReference": false
- Test: Ctrl+Click on rules.VARIABLE_NAME in Python files should not navigate to .rul files
Reverse References (.rul → Python):
- Disable: Set "rulefile.python.enableReverseReference": false
- Test: Right-click "Find All References" in .rul files should only show .rul references
- Test: Hover tooltips should not show Python reference counts
Both Features:
- Disable all Python integration: Set both settings to false
- Extension will function as a pure .rul file language support tool

Usage Examples

Parameter and Variable Headers

# Parameter definition (highlighted in blue)
PRODUCT_ID?    BATCH_ID?    UNIT_ID?

# Variable assignments (highlighted in purple)  
PRODUCT_ID:    TEST_MODE:         PROGRAM_VERSION:
X1A2          ['MODE_A']         ['1.0','1.1']
X2B3          ['MODE_B']         ['1.2'...'1.5']

Complex Value Recognition

# Mathematical expressions recognized as single values
MAX_LIMIT    100*int(MULTIPLIER_VALUE)    0

# Nested objects and arrays
CONFIG_MAP:    {'mapping':[{0:0}]}    ['OPTION_A']

# Function calls and scientific notation
VOLTAGE_LIMIT:      40e-6    int(CALC_VALUE)

Click on PRODUCT_ID? and press F12 to jump to all PRODUCT_ID: assignments
Right-click any identifier and select "Find All References" to see all usages in .rul AND Python files ✨
Press F2 on any header to rename it across the entire file
From Python files: Ctrl+Click on rules.VARIABLE_NAME to jump to .rul definition

Hover Information

Hover over any identifier to see:

Number of parameter usages
Number of variable assignments
Number of standalone references
Number of Python references ✨ NEW

Installation

Download the .vsix file
In VS Code, press Ctrl+Shift+P and run "Extensions: Install from VSIX..."
Select the downloaded file
Reload VS Code

File Association

The extension automatically activates for files with these extensions:

.rul

Language Configuration

The extension provides:

Auto-indentation with 2-space tabs
Bracket matching for [], {}, (), <>
Comment toggling with Ctrl+/
Region folding with #region / #endregion

Contributing

Found a bug or have a feature request? Please open an issue on the GitHub repository.

License

This extension is licensed under the MIT License.

Enjoy enhanced rule file editing with intelligent language support!

AX6 Rule File Syntax

Syahmi Zulkefli