Windev to Golang Conversion

Convert Windev (WLanguage) code to idiomatic Go, maintaining functionality while adapting to Go best practices.

Core Conversion Principles

1. Comment Handling

• IGNORE: Code commented out in Windev (lines starting with // at the beginning)
• PRESERVE: Descriptive comments explaining functionality, actions, and observations
• TRANSLATE: Convert Windev comment style to Go comment style
• Add Go documentation comments (starting with function name) for exported functions

2. Code Structure

• Convert Windev procedures to Go functions
• Convert Windev web services to Gin handlers
• Transform initialization code to main() or init() functions
• Adapt cleanup/finalization code to use defer statements

3. Mandatory Packages

• Logging: Use go.uber.org/zap for all logging operations
• APIs: Use github.com/gin-gonic/gin for web services and REST APIs
• Database: Use database/sql with appropriate drivers

4. Function Discovery

When encountering Windev functions without known Go equivalents:

• Check references/wlanguage-mapping.md first
• If not found, ASK the user: "I need a Go implementation for the Windev function [FunctionName]. Can you provide the equivalent or describe what it does?"
• Wait for clarification before proceeding
• Document new mappings for future reference

Conversion Workflow

Step 1: Analyze Source Code

Read the Windev code and identify:

• Procedures and functions
• Web service endpoints
• Database operations (HyperFileSQL or SQL)
• File operations
• Initialization/cleanup sections
• Global variables and constants
• External dependencies

Step 2: Load Reference Materials

Always read these references before conversion:

view references/wlanguage-mapping.md  # Function mappings
view references/windev-patterns.md    # Common patterns

Step 3: Plan Go Structure

Determine:

• Package organization
• Required imports
• Global variables (minimize these)
• Configuration approach
• Error handling strategy

Step 4: Convert Code

Follow these priorities:

1. Convert structures and types first
2. Convert utility functions
3. Convert business logic procedures
4. Convert API handlers last
5. Add proper error handling throughout
6. Add logging at key points

Step 5: Add Infrastructure

• Create main.go with initialization
• Setup database connection with pooling
• Configure Zap logger (development or production mode)
• Setup Gin router with middleware
• Add health check endpoint

Conversion Guidelines

Procedures to Functions

Windev:

PROCEDURE CalculateTotal(nQuantity is int, rPrice is real)
// Calculate the total with tax
rTotal is real
rTotal = nQuantity * rPrice * 1.15
RESULT rTotal

Go:

// CalculateTotal calculates the total price with tax
// quantity: number of items
// price: price per item
// Returns: total price including 15% tax
func CalculateTotal(quantity int, price float64) float64 {
    // Calculate the total with tax
    total := float64(quantity) * price * 1.15
    return total
}

Web Services to Gin Handlers

Windev:

PROCEDURE ws_GetProduct(nProductID is int)
stProduct is ST_Product

HReadSeek(Product, ProductID, nProductID)
IF HFound() THEN
    stProduct.Name = Product.Name
    stProduct.Price = Product.Price
    WebserviceWriteHTTPCode(200)
    RESULT VariantToJSON(stProduct)
ELSE
    WebserviceWriteHTTPCode(404)
    RESULT "Product not found"
END

Go:

// GetProduct retrieves a product by ID
// Converted from Windev: ws_GetProduct
func GetProduct(c *gin.Context) {
    productID, err := strconv.Atoi(c.Param("id"))
    if err != nil {
        logger.Error("invalid product ID", zap.Error(err))
        c.JSON(400, gin.H{"error": "Invalid product ID"})
        return
    }
    
    var product Product
    query := "SELECT id, name, price FROM products WHERE id = $1"
    err = db.QueryRow(query, productID).Scan(&product.ID, &product.Name, &product.Price)
    
    if err == sql.ErrNoRows {
        logger.Warn("product not found", zap.Int("productID", productID))
        c.JSON(404, gin.H{"error": "Product not found"})
        return
    }
    
    if err != nil {
        logger.Error("database error", zap.Error(err))
        c.JSON(500, gin.H{"error": "Internal server error"})
        return
    }
    
    logger.Info("product retrieved", zap.Int("productID", productID))
    c.JSON(200, product)
}

Database Operations

Convert HyperFileSQL operations to SQL queries:

Windev:

FOR EACH Product WHERE Category = sCategory
    stProduct.Name = Product.Name
    ArrayAdd(arrProducts, stProduct)
END

Go:

query := "SELECT id, name, price FROM products WHERE category = $1"
rows, err := db.Query(query, category)
if err != nil {
    logger.Error("query failed", zap.Error(err))
    return nil, fmt.Errorf("failed to query products: %w", err)
}
defer rows.Close()

var products []Product
for rows.Next() {
    var product Product
    if err := rows.Scan(&product.ID, &product.Name, &product.Price); err != nil {
        logger.Error("scan failed", zap.Error(err))
        return nil, fmt.Errorf("failed to scan product: %w", err)
    }
    products = append(products, product)
}

if err = rows.Err(); err != nil {
    logger.Error("rows error", zap.Error(err))
    return nil, fmt.Errorf("error iterating products: %w", err)
}

File Operations

Windev:

nFileID is int = fOpen(sFilePath, foRead)
WHILE NOT fEndOfFile(nFileID)
    sLine = fReadLine(nFileID)
    // Process line
END
fClose(nFileID)

Go:

file, err := os.Open(filePath)
if err != nil {
    logger.Error("cannot open file", zap.String("path", filePath), zap.Error(err))
    return fmt.Errorf("cannot open file: %w", err)
}
defer file.Close()

scanner := bufio.NewScanner(file)
for scanner.Scan() {
    line := scanner.Text()
    // Process line
}

if err := scanner.Err(); err != nil {
    logger.Error("scanner error", zap.Error(err))
    return fmt.Errorf("error reading file: %w", err)
}

Error Handling

Always use explicit error handling:

Windev:

WHEN EXCEPTION
    Error("Operation failed: " + ExceptionInfo())
END
bResult = DangerousOperation()

Go:

result, err := DangerousOperation()
if err != nil {
    logger.Error("operation failed", zap.Error(err))
    return fmt.Errorf("operation failed: %w", err)
}

Logging Standards

Use Zap logger consistently:

// Initialization
logger, _ := zap.NewProduction()
defer logger.Sync()

// Debug (detailed diagnostic info)
logger.Debug("processing item", zap.Int("itemID", id))

// Info (general informational messages)
logger.Info("user created", zap.String("username", username))

// Warn (warning conditions)
logger.Warn("item not found", zap.Int("itemID", id))

// Error (error conditions)
logger.Error("database connection failed", zap.Error(err))

// Fatal (application terminating errors)
logger.Fatal("cannot start server", zap.Error(err))

Project Structure

Organize converted code:

project/
├── main.go              # Application entry point
├── handlers.go          # Gin HTTP handlers (converted web services)
├── models.go            # Data structures
├── database.go          # Database operations
├── config.go            # Configuration management
├── utils.go             # Utility functions (converted procedures)
├── go.mod               # Go module definition
├── go.sum               # Dependencies checksums
└── .env.example         # Environment variables template

Templates

Use templates from assets/go-templates/:

• main.go: Application initialization and server setup
• handlers.go: Example API handlers with CRUD operations
• go.mod: Module definition with required dependencies
• .env.example: Environment configuration template

Copy templates to workspace and adapt to specific needs.

Common Conversions

Variable Declarations

Windev	Go
nValue is int	var value int or value := 0
rPrice is real	var price float64 or price := 0.0
sName is string	var name string or name := ""
bFlag is boolean	var flag bool or flag := false
dDate is date	var date time.Time
arrItems is array of X	var items []X or items := make([]X, 0)

Control Structures

Windev	Go
IF ... END	if { }
SWITCH ... END	switch { }
FOR ... END	for { }
WHILE ... END	for condition { }
FOR EACH ... END	for _, item := range items { }

Constants

Windev	Go
CONSTANT X = 10	const X = 10
True / False	true / false
Null	nil
CRLF	"\n"

Conversion Checklist

For each Windev file:

• Read and understand the code purpose
• Identify all procedures and functions
• Check for unknown Windev functions (ask user if needed)
• Remove commented code (lines starting with //)
• Preserve descriptive comments
• Convert variable declarations
• Convert control structures
• Convert database operations to SQL
• Convert file operations to Go standard library
• Add error handling
• Add Zap logging
• Convert web services to Gin handlers
• Test converted code logic
• Add function documentation
• Organize into appropriate package structure

Best Practices

1. Error Handling: Never ignore errors. Always check and handle appropriately.
2. Context Usage: Use context.Context for API handlers and database operations.
3. Database Connections: Use connection pooling, set reasonable limits.
4. Logging: Log at appropriate levels (Debug, Info, Warn, Error, Fatal).
5. Configuration: Use environment variables for configuration.
6. Testing: Write tests for converted business logic.
7. Documentation: Document exported functions with Go doc comments.
8. Code Style: Follow Go conventions (gofmt, golint).

Common Pitfalls

• Not checking errors: Go requires explicit error handling
• Ignoring context: Always use context for cancellation and timeouts
• SQL injection: Use parameterized queries, never string concatenation
• Not closing resources: Use defer for cleanup (files, connections, etc.)
• Global state: Minimize use of global variables
• Panic usage: Prefer returning errors over panic()

Example Conversion Session

User provides Windev code → Load references → Identify unknown functions → Ask user if needed → Convert procedures → Convert web services → Add infrastructure → Test → Deliver complete Go project

Additional Resources

When converting complex Windev systems:

• Consult references/wlanguage-mapping.md for function mappings
• Review references/windev-patterns.md for common patterns
• Use templates from assets/go-templates/ as starting point
• Ask user for clarification on business logic when needed
• Document any custom Windev functions for future reference