# strings.ludic — strings are values: compare with ==/!=, join with +, or (best)
# interpolate with `backticks {expr}`. Running it prints: 1 2 3 4 5 6 7
program Strings {
  entry {
    let greeting = "hello"
    if greeting == "hello" { print(1) }         # content comparison
    if greeting != "world" { print(2) }

    let who = "Ludic"
    let msg = greeting + ", " + who + "!"            # concatenation chains
    if msg == "hello, Ludic!" { print(3) }

    # build up a string in a loop
    var line = ""
    var i = 0
    while i < 3 { line = line + "ab"; i = i + 1 }
    if line == "ababab" { print(4) }

    if (greeting + who) != greeting { print(5) }

    # interpolation: `{expr}` embeds any expression (numbers become text)
    let n = 42
    if `{greeting}, {who}!` == "hello, Ludic!" { print(6) }
    if `n={n}, next={n + 1}` == "n=42, next=43" { print(7) }

    # slicing: s[a..b] is the substring of bytes [a, b), and len(s) its length
    let full = "hello world"
    if full[0..5] == "hello" { print(8) }
    if full[6..len(full)] == "world" { print(9) }
  }
}