Improve bin_creator to accept multi-line input

Author: RandomSearch18

README.md

@@ -75,14 +75,14 @@ cargo run --bin rusty_man_computer -- --ram demos/factorial.bin
 
 At the moment, the easiest way to write a program is using the assembly language in the [online simulator](https://peterhigginson.co.uk/lmc/). Write the assembly code, click "ASSEMBLE INTO RAM", and click-and-drag to copy the contents of the memory text boxes (you can leave out any empty memory at the end).
 
-At the moment, you have to use a text editor to ensure that each memory cell is only separated by a space, and not a line break. (This can also be accomplished by pasting the memory contents into the address bar of your browser, and copying it from there.)
-
 Then you can run `bin_creator`, giving it the file name that the binary file should be written to, e.g.
 
 ```bash
 cargo run --bin bin_creator -- my_program.bin
 ```
 
+Follow the prompt to paste the memory data into your terminal, and press Enter twice in a row to mark the end of the data.
+
 Then you can run the program as described above, e.g.
 
 ```bash

src/bin_creator.rs

@@ -14,10 +14,16 @@ fn main() -> Result<(), Box<dyn Error>> {
     let filename = &args[1];
 
     // Let the user paste in a string
-    println!("Paste in the memory data:");
+    println!("Paste the memory data below, then press Enter twice to submit:");
     let mut line = String::new();
     let stdin = io::stdin();
-    stdin.lock().read_line(&mut line)?;
+    // Accept input until enter is pressed twice
+    loop {
+        stdin.lock().read_line(&mut line)?;
+        if line.chars().rev().take(2).collect::<String>() == "\n\n" {
+            break;
+        }
+    }
 
     // Split the string into a vector i16 signed ints
     let memory_data_items: Vec<i16> = line
@@ -34,5 +40,6 @@ fn main() -> Result<(), Box<dyn Error>> {
     // Write the memory data to a binary file
     fs::write(filename, memory_data_bytes)?;
 
+    println!("Successfully created binary file: {}", filename);
     Ok(())
 }