Function index

aiscript-vm/src/builtins/array.rs:191–236

Return zero-based index of the first item with value equal to x

(
    _mc: &'gc Mutation<'gc>,
    receiver: Value<'gc>,
    args: Vec<Value<'gc>>,
)

// Return zero-based index of the first item with value equal to x
fn index<'gc>(
    _mc: &'gc Mutation<'gc>,
    receiver: Value<'gc>,
    args: Vec<Value<'gc>>,
) -> Result<Value<'gc>, VmError> {
    let list = receiver.as_array()?;

    if args.is_empty() {
        return Err(VmError::RuntimeError(
            "index: expected at least 1 argument".into(),
        ));
    }

    let value_to_find = &args[0];

    // Get optional start and end parameters
    let start: usize = if args.len() > 1 {
        float_arg!(&args, 1, "index")? as usize
    } else {
        0
    };

    let end: usize = if args.len() > 2 {
        float_arg!(&args, 2, "index")? as usize
    } else {
        list.borrow().data.len()
    };

    // Validate start and end
    let list_len = list.borrow().data.len();
    let start = start.min(list_len);
    let end = end.min(list_len);

    // Search for the value in the specified range
    for (i, item) in list.borrow().data[start..end].iter().enumerate() {
        if item.equals(value_to_find) {
            // Return relative to original list
            return Ok(Value::Number((i + start) as f64));
        }
    }

    Err(VmError::RuntimeError(format!(
        "index: value {} not found in list",
        value_to_find
    )))
}

// Returns a shallow copy of a portion of the array
fn slice<'gc>(