# Example 15: List@(T)
#
# This example demonstrates Sushi's List@(T) generic collection from the standard
# library. List@(T) is a growable array (dynamic vector) that automatically resizes
# as you add elements. It uses exponential growth (2x) for amortized O(1) push.
#
# Key concepts covered:
# - List@(T) is a built-in generic (no import required)
# - Generic collection List@(T) with compile-time type specialization
# - List creation: .new() and .with_capacity()
# - Adding elements: .push() with automatic resizing
# - Removing elements: .pop() returns Maybe@(T)
# - Safe element access: .get() returns Maybe@(T)
# - Iteration: .iter() for foreach loops
# - RAII cleanup: Lists automatically free memory when they go out of scope
#
# Note: List@(T) uses move semantics for dynamic arrays and provides methods for
# in-place modification. Elements are stored contiguously in memory for cache efficiency.


fn main() i32:
    # Create empty list with default capacity
    let List@(string) crew = List.new()

    # Add crew members - list grows automatically
    # Push is amortized O(1) due to exponential growth strategy
    crew.push("Arthur Dent")
    crew.push("Ford Prefect")
    crew.push("Zaphod Beeblebrox")
    crew.push("Trillian")
    crew.push("Marvin")

    println("Crew size: {crew.len()}")
    println("Capacity: {crew.capacity()}")  # Capacity >= length

    # Safe element access with bounds checking
    # .get() returns Maybe@(T) to handle out-of-bounds gracefully
    match crew.get(0):
        Maybe.Some(name) ->
            println("Captain: {name}")
        Maybe.None() ->
            println("Empty crew")

    # Iterate over all elements using .iter()
    println("All crew members:")

    foreach(member in crew.iter()):
        println("  - {member}")

    # Remove last element - returns Maybe@(T)
    # Returns Maybe.None() if the list is empty
    match crew.pop():
        Maybe.Some(name) ->
            println("Removed: {name}")
        Maybe.None() ->
            println("No one to remove")

    println("Remaining crew: {crew.len()}")

    # Pre-allocate capacity to avoid reallocations
    # Useful when you know the approximate size in advance
    let List@(i32) answers = List.with_capacity(10)

    answers.push(42)
    answers.push(42)
    answers.push(42)

    println("Number of answers: {answers.len()}")

    # List automatically cleans up when it goes out of scope (RAII)
    return Result.Ok(0)