| name | masm-file-structure |
| description | Enforce file structure and section ordering for Miden Assembly (.masm) files. Use when editing, reviewing, or creating .masm files. |
MASM File Structure
MASM files must follow a fixed section order. Use section headers with the long separator line:
# SECTION NAME
# =================================================================================================
Section Order
- Imports –
use statements only; no section header
- Type aliases –
type definitions
- Constants – see the masm-constants skill for organization (non-error constants first, then errors)
- Public interface –
pub proc procedures that form the module API
- Helper procedures –
proc (non-pub) procedures used internally
Example Structure
use miden::agglayer::bridge::bridge_config
use miden::agglayer::bridge::leaf_utils
use miden::core::mem
use miden::core::word
# TYPE ALIASES
# =================================================================================================
type BeWord = struct @bigendian { a: felt, b: felt, c: felt, d: felt }
type DoubleWord = struct { word_lo: BeWord, word_hi: BeWord }
type MemoryAddress = u32
# CONSTANTS
# =================================================================================================
const PROOF_DATA_PTR = 0
const PROOF_DATA_WORD_LEN = 134
# ERRORS
# =================================================================================================
const ERR_BRIDGE_NOT_MAINNET = "bridge not mainnet"
const ERR_LEADING_BITS_NON_ZERO = "leading bits of global index must be zero"
# PUBLIC INTERFACE
# =================================================================================================
#! Main entry point. Computes the leaf value and verifies it.
#!
#! Inputs: [LEAF_DATA_KEY, PROOF_DATA_KEY, pad(8)]
#! Outputs: [pad(16)]
#!
#! Invocation: call
pub proc verify_leaf_bridge
exec.get_leaf_value
exec.verify_leaf
end
# HELPER PROCEDURES
# =================================================================================================
#! Loads leaf data and computes the leaf value.
#!
#! Inputs: [LEAF_DATA_KEY]
#! Outputs: [LEAF_VALUE[8]]
#!
#! Invocation: exec
proc get_leaf_value(leaf_data_key: BeWord) -> DoubleWord
...
end
#! Verifies leaf against Merkle proof.
#!
#! Inputs: [LEAF_VALUE[8], PROOF_DATA_KEY]
#! Outputs: []
#!
#! Invocation: exec
proc verify_leaf
...
end
Guidelines
- Imports: One
use per line; group by module. No blank lines between imports.
- Type aliases: Define shared types (e.g.
DoubleWord, MemoryAddress) before constants or procedures.
- Constants: Follow the masm-constants skill.
- Public interface: Only
pub proc; these are the module’s API. Order by importance or call flow.
- Helper procedures: Non-pub procedures that support the public interface. May include
pub proc helpers (e.g. get_leaf_value) if they are used internally or re-exported, or used for unit tests.
When Sections Are Omitted
- No imports → start with type aliases or constants
- No type aliases → constants follow imports
- No helpers → public interface is the last section
Validation Checklist
