add better errors

src/lang.zig

@@ -1,13 +1,15 @@
 const std = @import("std");
 
+pub const ParseError = error{
+    NoCommandGiven,
+    UnknownCommand,
+};
+
 pub const CommandType = enum {
     Noop,
     Load,
     Amp,
     Quicksave,
-
-    // TODO proper errs
-    Error,
 };
 
 pub const Command = struct {
@@ -22,17 +24,18 @@ pub const Command = struct {
 pub const CommandList = std.ArrayList(*Command);
 pub const ArgList = std.ArrayList([]const u8);
 
-pub fn commandToCmdType(command: []const u8) CommandType {
+pub fn commandToCmdType(command: []const u8) ParseError!CommandType {
     if (std.mem.eql(u8, command, "noop")) {
-        return .Noop;
+        return CommandType.Noop;
     } else if (std.mem.eql(u8, command, "load")) {
-        return .Load;
+        return CommandType.Load;
     } else if (std.mem.eql(u8, command, "amp")) {
-        return .Amp;
+        return CommandType.Amp;
     } else if (std.mem.eql(u8, command, "quicksave")) {
-        return .Quicksave;
+        return CommandType.Quicksave;
     } else {
-        return .Error;
+        std.debug.warn("Unknown command: '{}'\n", command);
+        return ParseError.UnknownCommand;
     }
 }
 
@@ -55,9 +58,11 @@ pub const Lang = struct {
             // TODO better tokenizer instead of just tokenize(" ");
             var tok_it = std.mem.tokenize(stmt, " ");
 
-            // TODO send errors
-            var command = tok_it.next().?;
-            var ctype = commandToCmdType(command);
+            var cmd_opt = tok_it.next();
+            if (cmd_opt == null) return ParseError.NoCommandGiven;
+
+            var command = cmd_opt.?;
+            var ctype = try commandToCmdType(command);
             var args = ArgList.init(self.allocator);
 
             while (tok_it.next()) |arg| {