happy new year! implementing reading to mem from file

src/main.rs

@@ -6,7 +6,7 @@ use core::panic;
 // use std::fs;
 // use std::io;
 // use std::io::Read;
-use std::u16;
+use std::{env, u16};
 use mem::Memory;
 
 const PC_START: u16 = 0x300;
@@ -133,28 +133,11 @@ impl VM {
 
 
 fn main() {
-
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-
-	// let args: Vec<String> = env::args().collect();
-	// let	path = args.get(1).expect("enter a file please!");
-	// let file = fs::File::open(path).expect("couldnt open file");
-	// let mut reader = io::BufReader::new(file);
-	// let mut values = Vec::new();
-	// let mut buffer:[u8;2] = [0;2];
-	// while reader.read_exact(&mut buffer).is_ok() {
-	// 	let instruction = u16::from_be_bytes(buffer);
-	// 	values.push(instruction);
-	// }
-	// println!("data: {:?}\n", values);
-	// for data in values{
-	// 	println!("hex data: {:#06X}", data);
-	// }
+	let mut lc3 = VM::new();
+	let args: Vec<String> = env::args().collect();
+	let path = args.get(1).expect("a file must be specified");
+	lc3.memory.read(path.to_string());
+	for addr in 0x3000..0x3007 {
+		println!("the instruction is {:#b} at address {:#x}", lc3.memory.data[addr], addr);
+	}
 }

src/mem.rs

@@ -1,9 +1,11 @@
 #![allow(dead_code)]
 
+use std::{fs, io::{self, Read}};
+
 pub const MEM_SIZE: usize = u16::MAX as usize;
 
 pub struct Memory {
-	data: [u16; MEM_SIZE],
+	pub data: [u16; MEM_SIZE],
 }
 
 impl Memory {
@@ -19,4 +21,30 @@ impl Memory {
 	pub fn get(&mut self, addr: u16) {
 		self.data[addr as usize];
 	}
+
+	pub fn read(&mut self, path: String) {
+		// don't need byteorder crate!!
+		let file = fs::File::open(path).expect("could not open file");
+		let mut reader = io::BufReader::new(file);
+		let mut buffer: [u8;2] = [0, 2];
+		let _ = reader.read_exact(&mut buffer).expect("could not read file");
+		let base_addr = u16::from_be_bytes(buffer);
+		let mut addr = base_addr;
+		loop {
+		  match reader.read_exact(&mut buffer) {
+		    Ok(()) => {
+					let instruction = u16::from_be_bytes(buffer);
+					self.set(addr, instruction as u16);
+					addr += 1;
+				}
+				Err(e) => {
+					if e.kind() == std::io::ErrorKind::UnexpectedEof {
+						break;
+					} else {
+						panic!("could not read instruction {:?}", e);
+					}
+				}
+		  }
+		}
+	}
 }