main: add Result enum

src/main.zig

@@ -1,9 +1,43 @@
 const std = @import("std");
 
+pub const Result = enum {
+    Ok,
+    TokenizeError,
+    ParseError,
+    CompileError,
+};
+
+pub fn run(allocator: *std.mem.Allocator, slice: []const u8) Result {
+    return Result.Ok;
+}
+
 pub fn main() anyerror!void {
     const allocator = std.heap.direct_allocator;
     var args_it = std.process.args();
     _ = args_it.skip();
 
     const filepath = try (args_it.next(allocator) orelse @panic("expected file path"));
+
+    var file = try std.fs.File.openRead(filepath);
+    defer file.close();
+
+    const total_bytes = try file.getEndPos();
+
+    var slice = try allocator.alloc(u8, total_bytes);
+    defer allocator.free(slice);
+
+    _ = try file.read(slice);
+
+    //switch (try run(allocator, slice)) {
+    switch (run(allocator, slice)) {
+        .Ok => {},
+
+        .TokenizeError,
+        .ParseError,
+        .CompileError,
+        => |res| {
+            std.debug.warn("error: {}\n", res);
+            std.os.exit(1);
+        },
+    }
 }