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map

Maps in Soul are unordered collections of key-value pairs, similar to dictionaries or objects in other languages. They are created using curly braces {} and provide efficient lookup and modification of data.

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Basic Map Creation

Create maps with curly brace notation: 
// Empty map
empty = {}

// Map with string keys
user = {
    "name": "Alice",
    "age": 30,
    "email": "alice@example.com"
}

// Map with different key types
mixed = {
    "string_key": "value1",
    123: "numeric_key",
    true: "boolean_key"
}

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Accessing Map Values

Use bracket notation or dot notation to access values: 
person = {
    "firstName": "John",
    "lastName": "Doe",
    "age": 25
}

// Bracket notation
name = person["firstName"]      // "John"
age = person["age"]            // 25

// Dot notation (if supported)
lastName = person.lastName      // "Doe"

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Modifying Map Values

Add or change values using assignment: 
config = {
    "debug": false,
    "port": 8080
}

// Modify existing values
config["debug"] = true
config["port"] = 3000

// Add new key-value pairs
config["host"] = "localhost"
config["timeout"] = 5000

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Map Methods

Common map operations: 
data = {
    "name": "Alice",
    "age": 30,
    "city": "New York"
}

// Get all keys
keys = data.keys()              // ["name", "age", "city"]

// Get all values
values = data.values()          // ["Alice", 30, "New York"]

// Get size
size = data.size()              // 3
length = data.length()          // 3

// Check if key exists
hasName = data.hasKey("name")   // true
hasEmail = data.hasKey("email") // false

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Map Iteration

Iterate through map key-value pairs: 
settings = {
    "theme": "dark",
    "language": "en",
    "notifications": true
}

// For-in loop with key and value
for (key, value in settings) {
    println(key + ": " + value)
}

// For-in loop with keys only
for (key in settings) {
    println(key + " = " + settings[key])
}

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Nested Maps

Maps can contain other maps: 
user = {
    "profile": {
        "name": "Alice",
        "age": 30
    },
    "preferences": {
        "theme": "dark",
        "notifications": true
    }
}

// Access nested values
name = user["profile"]["name"]                    // "Alice"
theme = user["preferences"]["theme"]              // "dark"

// Modify nested values
user["profile"]["age"] = 31
user["preferences"]["language"] = "en"

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Map with Different Value Types

Maps can store different types of values: 
mixedData = {
    "string": "hello",
    "number": 42,
    "boolean": true,
    "null": null,
    "array": [1, 2, 3],
    "object": {
        "nested": "value"
    }
}

// Access different types
text = mixedData["string"]      // "hello"
num = mixedData["number"]       // 42
list = mixedData["array"]       // [1, 2, 3]
nested = mixedData["object"]["nested"]  // "value"

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Map Copying

Create copies of maps: 
original = {
    "name": "Alice",
    "age": 30
}

// Shallow copy
soul shallowCopy(map) {
    copy = {}
    for (key, value in map) {
        copy[key] = value
    }
    return copy
}

copied = shallowCopy(original)

​
Map Merging

Combine multiple maps: 
defaults = {
    "theme": "light",
    "language": "en",
    "timeout": 5000
}

userSettings = {
    "theme": "dark",
    "notifications": true
}

// Merge maps
soul merge(map1, map2) {
    result = {}
    
    // Copy first map
    for (key, value in map1) {
        result[key] = value
    }
    
    // Copy second map (overwrites conflicts)
    for (key, value in map2) {
        result[key] = value
    }
    
    return result
}

finalSettings = merge(defaults, userSettings)

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Map Filtering

Filter map entries based on conditions: 
data = {
    "apple": 5,
    "banana": 3,
    "cherry": 8,
    "date": 2
}

// Filter by value
soul filterByValue(map, minValue) {
    result = {}
    for (key, value in map) {
        if (value >= minValue) {
            result[key] = value
        }
    }
    return result
}

filtered = filterByValue(data, 5)  // {"apple": 5, "cherry": 8}

​
Map Transformation

Transform map values: 
prices = {
    "apple": 1.50,
    "banana": 0.80,
    "cherry": 2.00
}

// Apply discount
soul applyDiscount(priceMap, discountPercent) {
    result = {}
    for (item, price in priceMap) {
        discountedPrice = price * (1 - discountPercent / 100)
        result[item] = discountedPrice
    }
    return result
}

discountedPrices = applyDiscount(prices, 10)  // 10% discount

​
Map Searching

Find entries in maps: 
users = {
    "alice": {"age": 25, "role": "admin"},
    "bob": {"age": 30, "role": "user"},
    "charlie": {"age": 35, "role": "user"}
}

// Find by property
soul findByRole(userMap, targetRole) {
    result = {}
    for (username, userData in userMap) {
        if (userData["role"] == targetRole) {
            result[username] = userData
        }
    }
    return result
}

admins = findByRole(users, "admin")

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Map Validation

Validate map structure and content: 
soul validateUserMap(userMap) {
    requiredFields = ["name", "email", "age"]
    
    for (field in requiredFields) {
        if (!userMap.hasKey(field)) {
            return false
        }
    }
    
    // Validate email format
    if (!userMap["email"].contains("@")) {
        return false
    }
    
    // Validate age
    if (userMap["age"] < 0 || userMap["age"] > 150) {
        return false
    }
    
    return true
}

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Map Utilities

Common map utility functions: 
// Check if map is empty
soul isEmpty(map) {
    return map.size() == 0
}

// Get value with default
soul getWithDefault(map, key, defaultValue) {
    if (map.hasKey(key)) {
        return map[key]
    }
    return defaultValue
}

// Remove key
soul removeKey(map, key) {
    if (map.hasKey(key)) {
        value = map[key]
        delete map[key]  // If supported
        return value
    }
    return null
}

​
Map Configuration

Use maps for configuration: 
appConfig = {
    "database": {
        "host": "localhost",
        "port": 5432,
        "name": "myapp"
    },
    "server": {
        "port": 8080,
        "host": "0.0.0.0"
    },
    "logging": {
        "level": "info",
        "file": "app.log"
    }
}

// Access configuration
dbHost = appConfig["database"]["host"]
serverPort = appConfig["server"]["port"]
logLevel = appConfig["logging"]["level"]

​
Map as Cache

Use maps for caching: 
cache = {}

soul getCachedValue(key) {
    if (cache.hasKey(key)) {
        return cache[key]
    }
    
    // Compute and cache value
    value = expensiveComputation(key)
    cache[key] = value
    return value
}

soul clearCache() {
    cache = {}
}

​
Map Performance

Optimize map operations: 
// Batch operations
soul batchUpdate(map, updates) {
    for (key, value in updates) {
        map[key] = value
    }
}

// Efficient key checking
soul hasAllKeys(map, keys) {
    for (key in keys) {
        if (!map.hasKey(key)) {
            return false
        }
    }
    return true
}

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Best Practices

  1. Use meaningful keys: Choose descriptive key names
  2. Check key existence: Verify keys exist before accessing
  3. Handle null values: Account for missing or null values
  4. Use consistent types: Keep key types consistent within a map
  5. Validate structure: Check map structure before use
// Good - safe map access
soul getNestedValue(map, keys) {
    current = map
    
    for (key in keys) {
        if (current == null || !current.hasKey(key)) {
            return null
        }
        current = current[key]
    }
    
    return current
}

// Better - with error handling
soul getNestedValue(map, keys) {
    if (map == null || keys == null || keys.length() == 0) {
        return null
    }
    
    current = map
    
    for (key in keys) {
        if (current == null || typeof current != "object") {
            return null
        }
        
        if (!current.hasKey(key)) {
            return null
        }
        
        current = current[key]
    }
    
    return current
}

// Usage
userEmail = getNestedValue(user, ["profile", "contact", "email"])
Maps are essential data structures in Soul, providing efficient key-value storage and retrieval for organizing and managing data in your applications.
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