hexspell 1.0.0

Dependency-free Rust library for parsing and patching PE, ELF, and Mach-O executables with a 1:1 on-disk API
Documentation 
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//! Helper routines for safely reading integers from byte slices.
//!
//! Many parts of the crate need to interpret raw data at specific offsets.
//! The functions provided here centralize that logic, performing bounds
//! checks and converting little‑endian byte sequences into native Rust
//! integers. Errors are reported using [`FileParseError`], allowing callers
//! to bubble failures up without panicking.

use crate::errors::FileParseError;

/// Reads a little-endian `u64` at `offset`, returning [`FileParseError::BufferOverflow`] on truncation.
pub fn extract_u64(buffer: &[u8], offset: usize) -> Result<u64, FileParseError> {
    buffer
        .get(offset..offset + 8)
        .ok_or(FileParseError::BufferOverflow)
        .and_then(|bytes| bytes.try_into().map_err(|_| FileParseError::BufferOverflow))
        .map(u64::from_le_bytes)
}

/// Reads a little-endian `u32` at `offset`, returning [`FileParseError::BufferOverflow`] on truncation.
pub fn extract_u32(buffer: &[u8], offset: usize) -> Result<u32, FileParseError> {
    buffer
        .get(offset..offset + 4)
        .ok_or(FileParseError::BufferOverflow)
        .and_then(|bytes| {
            bytes
                .try_into()
                .map_err(|_| FileParseError::BufferOverflow)
                .map(u32::from_le_bytes)
        })
}

/// Reads a little-endian `u16` at `offset`, returning [`FileParseError::BufferOverflow`] on truncation.
pub fn extract_u16(buffer: &[u8], offset: usize) -> Result<u16, FileParseError> {
    buffer
        .get(offset..offset + 2)
        .ok_or(FileParseError::BufferOverflow)
        .and_then(|bytes| bytes.try_into().map_err(|_| FileParseError::BufferOverflow))
        .map(u16::from_le_bytes)
}