Module abi 

ABI (Application Binary Interface) helpers for function dispatch and calldata parsing.

This module provides utilities for:

• Computing function selectors from names
• Extracting selectors from calldata
• Reading typed values from calldata at specific offsets

Function Selectors

TruthLinked uses FNV-1a 32-bit hashing for function selectors (4 bytes). This is deterministic, no-std compatible, and provides good distribution.

Example

use truthlinked_sdk::abi;

// Compute selector for "transfer" function
let sel = abi::selector_of("transfer");

// Parse selector from calldata
let calldata = context::calldata()?;
let selector = abi::selector(&calldata)?;

// Read arguments
let amount = abi::read_u64(&calldata, 4)?;
let recipient = abi::read_account(&calldata, 12)?;

Constants

ERR_BAD_CALLDATA

Error code for malformed or insufficient calldata.

Functions

read_account

Reads a 32-byte account ID from calldata at the specified byte offset.

read_u64

Reads a u64 value from calldata at the specified byte offset.

read_u128

Reads a u128 value from calldata at the specified byte offset.

selector

Extracts the 4-byte function selector from calldata.

selector_of

Computes a 4-byte function selector from a function name.