src/main.zig

@@ -9,6 +9,13 @@ pub fn main() !void {
     var ln = Linenoise.init(allocator);
     defer ln.deinit();
 
+    var prng = Random.DefaultPrng.init(blk: {
+        var seed: u64 = undefined;
+        try std.posix.getrandom(std.mem.asBytes(&seed));
+        break :blk seed;
+    });
+    const rand = prng.random();
+
     const p = try getPrompt(allocator);
     defer allocator.free(p);
 
@@ -18,13 +25,73 @@ pub fn main() !void {
             try ln.history.add(input);
             const command = try tokenizeCommand(input, allocator);
             defer allocator.free(command);
+            if (mathTest(rand, 100)) {
                 _ = runCommand(command, allocator) catch |err| switch (err) {
                     error.FileNotFound => print("mash: {s}: command not found\n", .{command[0]}),
                     error.AccessDenied => print("mash: {s}: Permission denied\n", .{command[0]}),
                     else => print("Unkown error: {}\n", .{err}),
                 };
+            } else {
+                print(
+                    \\\n
+                    \\How can you expect to execute commands without knowing any math???\n
+                    \\\n
+                , .{});
             }
         }
+    }
+}
+
+const Operators = enum {
+    add,
+    subtract,
+    multiply,
+    divide,
+
+    const Self = @This();
+
+    fn toString(s: Self) []const u8 {
+        return switch (s) {
+            .add => "+",
+            .subtract => "-",
+            .multiply => "*",
+            .divide => "/",
+        };
+    }
+
+    fn apply(s: Self, a: i32, b: i32) i32 {
+        return switch (s) {
+            .add => a + b,
+            .subtract => a - b,
+            .multiply => a * b,
+            .divide => @divTrunc(a, b),
+        };
+    }
+};
+
+/// return true if the user passed, false if the user did not.
+fn mathTest(rand: Random, limit: i32) bool {
+
+    // const operators = comptime .{
+    //     .{ "+", add },
+    //     .{ "-", subtract },
+    //     .{ "*", multiply },
+    //     .{ "/", divide },
+    // };
+    // const ops = StaticStringMap(BinaryOperator).initComptime(operators);
+    // _ = ops;
+    const op = rand.enumValue(Operators);
+    const num1 = rand.intRangeAtMost(i32, 1, limit);
+    const num2 = rand.intRangeAtMost(i32, 1, limit);
+    const answer = op.apply(num1, num2);
+    print("{d} {s} {d} = {d}\n", .{ num1, op.toString(), num2, answer });
+    return true;
+}
+
+fn runCommand(command: [][]const u8, allocator: Allocator) !u8 {
+    var child = process.Child.init(command, allocator);
+    const result = try child.spawnAndWait();
+    return result.Exited;
 }
 
 fn getPrompt(allocator: Allocator) ![]const u8 {
@@ -37,12 +104,6 @@ fn getPrompt(allocator: Allocator) ![]const u8 {
     return result.stdout;
 }
 
-fn runCommand(command: [][]const u8, allocator: Allocator) !u8 {
-    var child = process.Child.init(command, allocator);
-    const result = try child.spawnAndWait();
-    return result.Exited;
-}
-
 fn tokenizeCommand(command: []const u8, allocator: Allocator) ![][]const u8 {
     var argv_array_list = ArrayList([]const u8).init(allocator);
     defer argv_array_list.deinit();
@@ -68,4 +129,6 @@ const tokenizeAny = std.mem.tokenizeAny;
 const process = std.process;
 const Allocator = std.mem.Allocator;
 const ArrayList = std.ArrayList;
+const StaticStringMap = std.static_string_map.StaticStringMap;
+const Random = std.Random;
 const Linenoise = @import("linenoise").Linenoise;