windjammer 0.48.0

// Conformance Test: string Operations
//
// SEMANTIC CONTRACT:
// - Strings are UTF-8 encoded text
// - String literals create string values
// - Concatenation with + joins strings
// - String interpolation with ${expr} works
// - len() returns byte length
// - Equality comparison works
// - Basic string methods work (to_uppercase, etc.)
//
// EXPECTED OUTPUT:
// [str_literal] hello
// [str_concat] hello world
// [str_interp] name=Alice, age=30
// [str_interp] result: 2 + 3 = 5
// [str_len] empty=0, hello=5, emoji=4
// [str_eq] same: true
// [str_eq] different: false
// [str_eq] not_equal: true
// [str_multi_concat] a-b-c-d
// [str_in_struct] greeting: Hello, Bob!
// [str_empty] is empty: true
// [str_empty] after assign: false
// [str_all] PASSED

// --- String literals ---
fn test_str_literal() {
    let s = "hello"
    println("[str_literal] ${s}")
}

// --- String concatenation ---
fn test_str_concat() {
    let a = "hello"
    let b = " world"
    let c = a + b
    println("[str_concat] ${c}")
}

// --- String interpolation ---
fn test_str_interpolation() {
    let name = "Alice"
    let age = 30
    println("[str_interp] name=${name}, age=${age}")

    let x = 2
    let y = 3
    let sum = x + y
    println("[str_interp] result: ${x} + ${y} = ${sum}")
}

// --- String length ---
fn test_str_len() {
    let empty = ""
    let hello = "hello"
    let emoji = "🎉"  // 4 bytes in UTF-8
    println("[str_len] empty=${empty.len()}, hello=${hello.len()}, emoji=${emoji.len()}")
}

// --- String equality ---
fn test_str_equality() {
    let a = "test"
    let b = "test"
    let c = "other"
    println("[str_eq] same: ${a == b}")
    println("[str_eq] different: ${a == c}")
    println("[str_eq] not_equal: ${a != c}")
}

// --- Multi-step concatenation ---
fn test_str_multi_concat() {
    let parts = vec!["a", "b", "c", "d"]
    let mut result = ""
    for part in parts {
        if result.len() > 0 {
            result = result + "-"
        }
        result = result + part
    }
    println("[str_multi_concat] ${result}")
}

// --- Strings in structs ---
struct Greeter {
    prefix: string,
}

impl Greeter {
    fn greet(self, name: string) -> string {
        self.prefix.clone() + ", " + name + "!"
    }
}

fn test_str_in_struct() {
    let g = Greeter { prefix: "Hello" }
    let msg = g.greet("Bob")
    println("[str_in_struct] greeting: ${msg}")
}

// --- Empty string checks ---
fn test_str_empty() {
    let mut s = ""
    println("[str_empty] is empty: ${s.is_empty()}")
    s = "hello"
    println("[str_empty] after assign: ${s.is_empty()}")
}

fn main() {
    test_str_literal()
    test_str_concat()
    test_str_interpolation()
    test_str_len()
    test_str_equality()
    test_str_multi_concat()
    test_str_in_struct()
    test_str_empty()
    println("[str_all] PASSED")
}