bhd: sort out basic nom parsing

src/main.rs

@@ -1,12 +1,14 @@
-extern crate clap;
-
 use std::fs::File;
-use std::io::{BufReader, Error, Read};
+use std::io::{Error, Read};
-
-//use std::path::Path;
 
+extern crate clap;
 use clap::{App, AppSettings, Arg, ArgMatches, SubCommand};
 
+mod parsers {
+    pub mod bhd;
+}
+use parsers::*;
+
 fn main() {
     let matches = App::new("Rusted Iron Ring")
         .setting(AppSettings::ArgRequiredElseHelp)
@@ -34,11 +36,10 @@ fn cmd_bhd(args: &ArgMatches) -> Result::<(), Error> {
     println!("File: {:?}", filepath);
     println!("Output: {:?}", outputpath);
 
-    let bhd_data: File = File::open(filepath)?;
+    let mut bhd_file: File = File::open(filepath)?;
-    let mut bhd_reader = BufReader::new(bhd_data);
+    let mut bhd_data = vec![0u8; bhd_file.metadata()?.len() as usize];
-    let mut magic: [u8; 4] = [0; 4];
+    bhd_file.read_to_end(&mut bhd_data)?;
-    bhd_reader.read(&mut magic)?;
 
-    println!("First byte: 0x{:X}", magic[0]);
+    bhd::parse(&bhd_data);
     Ok(())
 }

src/parsers/bhd.rs

@@ -1,13 +1,23 @@
 extern crate nom;
+use nom::{IResult, named, verify};
+use nom::number::complete::*;
 
 #[derive(Debug)]
 pub struct BhdHeader {
-    pub magic: u8[4];
+    pub magic: u32,
-    pub unk04: i8;
+//    pub unk04: i8,
-    pub unk05: i8;
+//    pub unk05: i8,
-    pub unk06: i8;
+//    pub unk06: i8,
-    pub unk07: i8;
+//    pub unk07: i8,
-    pub unk08: u32;
+//    pub unk08: u32,
-    pub num_buckets: u32;
+//    pub num_buckets: u32,
-    pub ofs_buckets: u32;
+//    pub ofs_buckets: u32,
+}
+
+const MAGIC: u32 = 0x35444842;
+named!(check_magic<&[u8], u32>, verify!(le_u32, |m| *m == MAGIC));
+
+pub fn parse(i: &[u8]) -> IResult<&[u8], BhdHeader> {
+    let (i, magic) = check_magic(i)?;
+    Ok((i, BhdHeader { magic }))
 }