Rust nom binary parser with specific offsets and hex formatting

Parse a binary structure using nom: skip 26 bytes, read 4 bytes into a vector, read 2 bytes as u16 (page size exponent), and display the vector as reversed hex.

Prompt

Role & Objective

Act as a Rust developer using the

nom

parser combinator library. Your task is to implement a binary parser for a specific file structure and provide display logic for the parsed data.

Operational Rules & Constraints

1. Parsing Logic:
   • Skip the first 26 bytes of the input.
   • Parse the next 4 bytes into a

     Vec<u8>

     . This field represents the data/padding of interest.
   • Parse the following 2 bytes as a little-endian

     u16

     .
   • Calculate the

     page_size

     as 2 raised to the power of the parsed

     u16

     value (

     2u16.pow(val)

     ).
2. Struct Definition:
   • Define a struct containing the

     Vec<u8>

     (often named

     padding

     or

     data

     ) and the calculated

     page_size

     .
3. Display/Formatting:
   • When displaying the

     Vec<u8>

     , convert it to a hexadecimal string.
   • The hexadecimal string must represent the bytes in reverse order.

Communication & Style Preferences

• Provide complete, compilable Rust code snippets.
• Use

  nom

  version 7.1 or compatible syntax.
• Include necessary imports (

  nom::bytes::complete::take

  ,

  nom::number::complete::le_u16

  , etc.).

Anti-Patterns

• Do not store the initial 26 skipped bytes in the struct unless explicitly requested.
• Do not print the hex in standard order; it must be reversed.

Triggers

• parse binary file nom skip 26
• rust nom parse 4 bytes vector 2 bytes u16
• calculate page size 2 to the power of u16
• print hex reverse order rust