Basic vasm cli wrapper

vasm/Cargo.toml

@@ -7,3 +7,5 @@ edition = "2021"
 
 [dependencies]
 vasm_core = { path = "../vasm_core" }
+clap = { version = "3.1.18", features = ["derive"] }
+regex = "1.7.0"

vasm/src/main.rs

@@ -1,3 +1,63 @@
-fn main() {
-    println!("Hello, world!");
+use std::fs::File;
+use std::io::Write;
+use clap::lazy_static::lazy_static;
+use clap::Parser;
+use regex::Regex;
+
+/// Vulcan Assembler
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+struct Args {
+    /// File to output to
+    #[clap(short, long)]
+    output: Option<String>,
+
+    /// Input file
+    #[clap()]
+    file: String,
+}
+
+impl Args {
+    fn warning(&self) -> Option<String> {
+        if !self.file.ends_with(".asm") {
+            return Some(format!("Warning: input file {} does not end in \".asm\"", self.file))
+        }
+        if let Some(output) = self.output.as_ref() {
+            // Warn if it doesn't match /.rom$/
+            if !output.ends_with(".rom") {
+                return Some(format!("Warning: output file {} does not end in \".rom\"", output))
+            }
+        }
+        None
+    }
+
+    fn deduce(&mut self) {
+        if self.output.is_none() {
+            let re = Regex::new(r"^(.*)\.asm$").unwrap();
+            if let Some(cap) = re.captures(self.file.as_ref()) {
+                self.output = Some(format!("{}.rom", cap.get(1).unwrap().as_str()));
+            } else {
+                panic!("No output file specified, couldn't deduce one from input filename")
+            }
+        }
+    }
+}
+
+fn main() {
+    let mut args = Args::parse();
+    if let Some(warning) = args.warning() {
+        println!("{}", warning);
+    }
+    args.deduce();
+
+    match vasm_core::assemble_file(args.file.as_str()) {
+        Ok(bytes) => {
+            //println!("We got some bytes... {} of them", bytes.len());
+            let mut outfile = File::create(args.output.unwrap()).expect("Failed to open output file");
+            outfile.write(bytes.as_slice()).expect("Failed to write to output file");
+        }
+        Err(error) => {
+            println!("{}", error)
+        }
+    }
 }