add basic runner

src/main.zig

@@ -17,6 +17,7 @@
 
 const std = @import("std");
 const langs = @import("lang.zig");
+const runners = @import("runner.zig");
 
 const c = @cImport({
     @cInclude("assert.h");
@@ -304,6 +305,7 @@ pub fn main() !void {
     const allocator = &arena.allocator;
 
     var lang = langs.Lang.init(allocator);
+    var runner = runners.Runner.init(allocator);
     //defer lang.deinit();
 
     var args_it = std.process.args();
@@ -324,6 +326,7 @@ pub fn main() !void {
     _ = try file.read(data);
 
     var cmds = try lang.parse(data);
+    try runner.runCommands(cmds);
     var it = cmds.iterator();
     while (it.next()) |cmd| {
         cmd.print();

src/runner.zig

@@ -0,0 +1,30 @@
+const std = @import("std");
+const lang = @import("lang.zig");
+
+pub const RunError = error{UnknownCommand};
+
+pub const Runner = struct {
+    allocator: *std.mem.Allocator,
+
+    pub fn init(allocator: *std.mem.Allocator) Runner {
+        return Runner{ .allocator = allocator };
+    }
+
+    fn runCommand(self: *Runner, cmd: *lang.Command) !void {
+        return switch (cmd.command) {
+            .Noop => {},
+            else => blk: {
+                std.debug.warn("Unknown command: {}\n", cmd.command);
+                break :blk RunError.UnknownCommand;
+            },
+        };
+    }
+
+    pub fn runCommands(self: *Runner, cmds: lang.CommandList) !void {
+        var it = cmds.iterator();
+
+        while (it.next()) |cmd| {
+            try self.runCommand(cmd);
+        }
+    }
+};