got some basics working!

src/bin/ngrun.rs

@@ -33,19 +33,37 @@ fn print_result<E>(result: (Value<E>, String)) {
     println!("RESULT: {}", result.0);
 }
 
-fn main() -> Result<(), anyhow::Error> {
+fn jit(ir: ngr::ir::Program<ngr::ir::Type>) -> Result<fn(), ngr::backend::BackendError> {
+    let mut backend = Backend::jit(None)?;
+    let function_id = backend.compile_program("gogogo", ir)?;
+    backend.module.finalize_definitions()?;
+    let compiled_bytes = backend.bytes(function_id);
+    Ok(unsafe { std::mem::transmute::<_, fn() -> ()>(compiled_bytes) })
+}
+
+fn main() {
     let cli = CommandLineArguments::parse();
     let mut file_database = SimpleFiles::new();
     let mut console = StandardStream::stdout(pretty::termcolor::ColorChoice::Auto);
     let console_options = codespan_reporting::term::Config::default();
-    let syntax = syntax::Program::parse_file(&mut file_database, cli.file.as_ref())?;
+    let syntax = syntax::Program::parse_file(&mut file_database, cli.file.as_ref());
     let mut emit = |x| {
         let _ = codespan_reporting::term::emit(&mut console, &console_options, &file_database, &x);
     };
+    let syntax = match syntax {
+        Ok(x) => x,
+        Err(e) => {
+            emit((&e).into());
+            return;
+        }
+    };
 
     if cli.interpreter == Interpreter::Syntax {
-        print_result(syntax.eval()?);
-        return Ok(());
+        match syntax.eval() {
+            Err(e) => println!("Evaluation error: {}", e),
+            Ok(v) => print_result(v),
+        }
+        return;
     }
 
     let ir = match syntax.type_infer() {
@@ -62,21 +80,20 @@ fn main() -> Result<(), anyhow::Error> {
             for error in errors {
                 emit(error.into());
             }
-            return Err(anyhow::anyhow!("failed to infer program types"));
+            return;
         }
     };
 
     if cli.interpreter == Interpreter::IR {
-        print_result(ir.eval()?);
-        return Ok(());
+        match ir.eval() {
+            Err(e) => println!("Evaluation error: {}", e),
+            Ok(v) => print_result(v),
+        }
+        return;
     }
 
-    let mut backend = Backend::jit(None)?;
-    let function_id = backend.compile_program("gogogo", ir)?;
-    backend.module.finalize_definitions()?;
-    let compiled_bytes = backend.bytes(function_id);
-    let compiled_function = unsafe { std::mem::transmute::<_, fn() -> ()>(compiled_bytes) };
-    compiled_function();
-
-    Ok(())
+    match jit(ir) {
+        Err(e) => emit(e.into()),
+        Ok(compiled_function) => compiled_function(),
+    }
 }