Icon LinkSway Migrations Guide

Icon LinkAugust 16, 2024

Release v0.63.0 Icon Link

Icon Link#[namespace()] attribute is no longer supported - #6279 Icon Link

We no longer support the #[namespace()] attribute. If you use it, notably with SRC14, you should migrate to using the in keyword if you want backwards compatibility. If you just care about namespacing, you should use the new namespacing syntax.

Backwards compatibility places foo at sha256("storage_example_namespace_0")

// before
#[namespace(example_namespace)]
storage {
    foo: u64 = 0,
}

// after
storage {
    foo in 0x1102bf23d7c2114d6b409df4a1f8f7982eda775e800267be65c1cc2a93cb6c5c: u64 = 0,
}

New / recommended method places foo at sha256("storage::example_namespace.foo")

// new
storage {
    example_namespace {
        foo: u64 = 0,
    },
}

Icon LinkConfigurables are no longer allowed in pattern matching and shadowing - #6289 Icon Link

The code below does not compile any more.

configurable {
    X: u8 = 10,
}
 
fn main() {
    let X = 101u8; // ERROR: Variable "X" shadows configurable of the same name.
}

configurable {
    X: u8 = 10,
}
 
fn main() {
    match var {
        (0, X) => true // ERROR: "X" is a configurable and configurables cannot be matched against.
    }
}

Icon LinkNew ABI specification format - #6254 Icon Link

The new ABI specification format is hash based to improve support for indexing. There were also updates to support the latest VM features.

Icon LinkAdded variable length message support when verifying ed signatures - #6419 Icon Link

ed_verify was changed to use Bytes for the message instead of b256 for a message hash.

// before
pub fn ed_verify(public_key: b256, signature: B512, msg_hash: b256)

// after
pub fn ed_verify(public_key: b256, signature: B512, msg: Bytes)

Icon LinkSome STD functions now return an Option instead of reverting - #6405 Icon Link, #6414 Icon Link, #6418 Icon Link

Some functions in the STD now return an Option instead of reverting. This allows developers to fail gracefully. More functions will do this in the future.

// before
let my_predicate_address: Address = predicate_address();

// after
let my_predicate_address: Address = predicate_address().unwrap();

Icon LinkSome STD functions now return types have been updated to match the Fuel Specifications

• output_count() now returns a u16 over a u64

Before:

let output_count: u64 = output_count();

After:

let my_output_count: u16 = output_count();

• tx_maturity now returns an Option<u32> over an Option<u64>

Before:

let my_tx_maturity: u64 = tx_maturity().unwrap()

After:

let my_tx_maturity: u32 = tx_maturity().unwrap()

Icon LinkSome STD functions have been made private. These will no longer be available for developers to use

• input_pointer()
• output_pointer()
• tx_witness_pointer()
• tx_script_start_pointer()
• tx_script_data_start_pointer()

The following functions now follow this format:

Inputs:

• input_type()
• input_predicate_data()
• input_predicate()
• input_message_sender()
• input_message_recipient()
• input_message_data_length()
• input_message_data()
• input_message_nonce()

Outputs:

• output_type()
• output_amount()

Transactions:

• tx_script_length()
• tx_script_data_length()
• tx_witness_data_length()
• tx_witness_data()
• tx_script_data()
• tx_script_bytecode()
• tx_script_bytecode_hash()

Icon LinkNon-breaking Changes

New partial support for slices.

Automated proxy creation and deployment with forc.