Strings

In Autolang, String represents immutable UTF-8 text. Strings provide rich inspection, slicing, and functional transformation operations.

Creation & Raw Multiline Strings

Construct strings using standard double quotes or raw multiline triple quotes ("""..."""). Raw strings preserve backslashes verbatim and support string interpolation using $variable or ${expression}.

val customer = "Acme Corp"
val orderCount = 12

// Standard interpolation
val summary = "Account ${customer} has ${orderCount} active orders."
println(summary)

// Raw multiline string (preserves backslashes without escape characters)
val queryPayload = """{
    "filter": "status = 'ACTIVE'",
    "path": "C:\services\logs\app.log"
}"""
println(queryPayload)

Characters & String Indexing

Autolang has a first-class Char type. Indexing a string using str[index], str.charAt(index), str.first(), or str.last() yields a Char value.

val code = "ORD-920"

val firstChar: Char = code[0]
println("First char: " + firstChar) // O
println("First: " + code.first())   // O
println("Last: " + code.last())     // 0

// Character inspections
val isLetter = firstChar.isLetter()
val isDigit = code[4].isDigit()
println("First is letter: " + isLetter + ", fifth is digit: " + isDigit)

Search & Validation Operations

Inspect text content with case-sensitive or case-insensitive options, prefixes, and suffixes.

val endpoint = "https://api.enterprise.com/v1/orders"

println("Has https? " + endpoint.startsWith("https://")) // true
println("Ends with orders? " + endpoint.endsWith("/orders")) // true
println("Index of v1: " + endpoint.indexOf("v1")) // 27

// Case-insensitive search
val greeting = "Welcome Enterprise User"
val containsUser = greeting.contains("user", true)
println("Contains user (ignore case): " + containsUser) // true

Text Manipulation & Slicing

Strings are immutable. Methods like take, drop, trim, and replace return new String instances.

val rawToken = "  Bearer tok_abc123456xyz  "
val token = rawToken.trim().removePrefix("Bearer ")

println("Clean token: " + token)
println("Prefix: " + token.take(7))      // tok_abc
println("Suffix: " + token.takeLast(6))  // 123xyz

// Splitting with multiple delimiters
val timestamp = "2026-10-03T14:30:00Z"
val components = timestamp.split("T", ":")
println("Hour component: " + components[1]) // 14

Functional Pipelines on Strings

Strings can be transformed and inspected using higher-order lambda functions directly.

val serial = "AB-901-XZ"

// Predicates
val allAlphanumeric = serial.all { it.isLetterOrDigit() || it == '-' }
println("Valid serial: " + allAlphanumeric) // true

// Functional filter
val digitsOnly = serial.filter { it.isDigit() }
println("Digits only: " + digitsOnly) // 901

// Count occurrences
val hyphenCount = serial.count { it == '-' }
println("Hyphen count: " + hyphenCount) // 2

StringBuilder

For high-throughput string construction, StringBuilder provides efficient in-place buffer mutation.

val builder = StringBuilder("REPORT:")
builder.append(" status=OK")
builder.append(", records=")
builder.append(250)

println(builder.toString()) // REPORT: status=OK, records=250