Skip to main content

Documentation Index

Fetch the complete documentation index at: https://soul-lang.com/llms.txt

Use this file to discover all available pages before exploring further.

​
return

The return statement is used to exit a function and optionally return a value to the caller. It immediately terminates function execution and passes control back to the calling code.

​
Basic Return Statement

Return values from functions: 
soul add(a, b) {
    return a + b
}

soul greet(name) {
    return "Hello, " + name
}

// Usage
result = add(5, 3)      // 8
message = greet("Alice") // "Hello, Alice"

​
Return Without Value

Return without a specific value (returns null): 
soul printMessage(message) {
    println(message)
    return  // Explicit return without value
}

soul processData(data) {
    if (data == null) {
        return  // Early return
    }
    
    // Process data here
    println("Processing: " + data)
}

​
Early Return

Use return for early exit from functions: 
soul validateUser(user) {
    if (user == null) {
        return "User is null"
    }
    
    if (user.name == null || user.name == "") {
        return "Name is required"
    }
    
    if (user.age < 0 || user.age > 150) {
        return "Invalid age"
    }
    
    return "Valid user"
}

​
Return with Expressions

Return the result of expressions: 
soul calculateDiscount(price, percentage) {
    return price * (percentage / 100)
}

soul isAdult(age) {
    return age >= 18
}

soul getFullName(firstName, lastName) {
    return firstName + " " + lastName
}

​
Return with Complex Values

Return objects, arrays, and complex data structures: 
soul createUser(name, email) {
    return {
        "name": name,
        "email": email,
        "isActive": true,
        "createdAt": new Date()
    }
}

soul getNumbers(start, end) {
    numbers = []
    for (i = start; i <= end; i++) {
        numbers.push(i)
    }
    return numbers
}

​
Return in Conditional Statements

Return different values based on conditions: 
soul getGrade(score) {
    if (score >= 90) {
        return "A"
    } else if (score >= 80) {
        return "B"
    } else if (score >= 70) {
        return "C"
    } else if (score >= 60) {
        return "D"
    } else {
        return "F"
    }
}

soul processResult(success, data, error) {
    if (success) {
        return {
            "status": "success",
            "data": data
        }
    } else {
        return {
            "status": "error",
            "error": error
        }
    }
}

​
Return in Loops

Return from within loops: 
soul findUser(users, id) {
    for (user in users) {
        if (user.id == id) {
            return user  // Found user, return immediately
        }
    }
    return null  // User not found
}

soul findFirstEven(numbers) {
    for (num in numbers) {
        if (num % 2 == 0) {
            return num
        }
    }
    return null
}

​
Return with Error Handling

Return error states and success states: 
soul divide(a, b) {
    if (b == 0) {
        return {
            "success": false,
            "error": "Division by zero"
        }
    }
    
    return {
        "success": true,
        "result": a / b
    }
}

soul parseNumber(str) {
    if (str == null || str == "") {
        return {
            "success": false,
            "error": "Empty string"
        }
    }
    
    try {
        num = Number(str)
        return {
            "success": true,
            "value": num
        }
    } catch (error) {
        return {
            "success": false,
            "error": "Invalid number format"
        }
    }
}

​
Return in Async Functions

Return values from async functions: 
async soul fetchUserData(userId) {
    response = await http.get("/api/users/" + userId)
    return response.json()
}

async soul processAsync(data) {
    if (data == null) {
        return {
            "success": false,
            "error": "No data provided"
        }
    }
    
    result = await processData(data)
    return {
        "success": true,
        "result": result
    }
}

​
Return in Class Methods

Return values from class methods: 
sanctuary User {
    soul __genesis__(name, email) {
        this.name = name
        this.email = email
        this.isActive = true
    }
    
    soul getName() {
        return this.name
    }
    
    soul getInfo() {
        return {
            "name": this.name,
            "email": this.email,
            "isActive": this.isActive
        }
    }
    
    soul activate() {
        this.isActive = true
        return this  // Return self for chaining
    }
}

​
Return for Method Chaining

Return objects to enable method chaining: 
sanctuary Builder {
    soul __genesis__() {
        this.data = {}
    }
    
    soul setName(name) {
        this.data.name = name
        return this  // Enable chaining
    }
    
    soul setAge(age) {
        this.data.age = age
        return this  // Enable chaining
    }
    
    soul build() {
        return this.data
    }
}

// Usage with method chaining
user = Builder.new()
    .setName("Alice")
    .setAge(30)
    .build()

​
Return with Validation

Return validation results: 
soul validateEmail(email) {
    if (email == null || email == "") {
        return {
            "valid": false,
            "error": "Email is required"
        }
    }
    
    if (!email.contains("@")) {
        return {
            "valid": false,
            "error": "Email must contain @"
        }
    }
    
    if (!email.contains(".")) {
        return {
            "valid": false,
            "error": "Email must contain domain"
        }
    }
    
    return {
        "valid": true,
        "email": email.toLowerCase()
    }
}

​
Return with Computed Values

Return computed or calculated values: 
soul calculateStatistics(numbers) {
    if (numbers == null || numbers.length() == 0) {
        return {
            "count": 0,
            "sum": 0,
            "average": 0,
            "min": 0,
            "max": 0
        }
    }
    
    sum = 0
    min = numbers[0]
    max = numbers[0]
    
    for (num in numbers) {
        sum += num
        if (num < min) min = num
        if (num > max) max = num
    }
    
    return {
        "count": numbers.length(),
        "sum": sum,
        "average": sum / numbers.length(),
        "min": min,
        "max": max
    }
}

​
Return with Resource Cleanup

Return after cleaning up resources: 
soul processFile(filename) {
    file = null
    
    try {
        file = openFile(filename)
        
        if (file == null) {
            return {
                "success": false,
                "error": "Could not open file"
            }
        }
        
        data = file.read()
        result = processData(data)
        
        return {
            "success": true,
            "result": result
        }
    } catch (error) {
        return {
            "success": false,
            "error": error.toString()
        }
    } finally {
        if (file != null) {
            file.close()
        }
    }
}

​
Return Best Practices

Guidelines for using return statements: 
// Good - clear return values
soul calculatePrice(quantity, unitPrice) {
    if (quantity <= 0) {
        return 0
    }
    
    if (unitPrice <= 0) {
        return 0
    }
    
    return quantity * unitPrice
}

// Better - comprehensive return structure
soul calculatePrice(quantity, unitPrice) {
    // Validate inputs
    if (quantity == null || unitPrice == null) {
        return {
            "success": false,
            "error": "Missing required parameters",
            "price": 0
        }
    }
    
    if (quantity <= 0) {
        return {
            "success": false,
            "error": "Quantity must be positive",
            "price": 0
        }
    }
    
    if (unitPrice <= 0) {
        return {
            "success": false,
            "error": "Unit price must be positive",
            "price": 0
        }
    }
    
    // Calculate price
    totalPrice = quantity * unitPrice
    
    return {
        "success": true,
        "price": totalPrice,
        "quantity": quantity,
        "unitPrice": unitPrice
    }
}

​
Best Practices

  1. Return early: Use early returns to avoid deep nesting
  2. Return meaningful values: Make return values clear and useful
  3. Be consistent: Use consistent return patterns throughout your code
  4. Handle all cases: Ensure all code paths return appropriate values
  5. Document return values: Make it clear what functions return
// Good - early return pattern
soul processUser(user) {
    if (user == null) {
        return null
    }
    
    if (!user.isActive) {
        return null
    }
    
    if (user.age < 18) {
        return null
    }
    
    return {
        "name": user.name,
        "email": user.email,
        "status": "processed"
    }
}

// Better - descriptive return values
soul processUser(user) {
    if (user == null) {
        return { success: false, error: "User is null" }
    }
    
    if (!user.isActive) {
        return { success: false, error: "User is inactive" }
    }
    
    if (user.age < 18) {
        return { success: false, error: "User is under 18" }
    }
    
    return {
        success: true,
        user: {
            name: user.name,
            email: user.email,
            status: "processed"
        }
    }
}
The return statement is essential for controlling function flow and providing results to calling code. Use it effectively to create clear, predictable, and maintainable functions.