.drone.yml

@@ -5,4 +5,5 @@ steps:
 - name: build & test
   image: euantorano/zig:0.9.1
   commands:
-  - zig test src/main.zig
+  - zig build test
+  - $(find zig-cache -name test) main.zig

.vscode/tasks.json

@@ -44,7 +44,7 @@
 		{
 			"label": "Test",
 			"type": "shell",
-			"command": "zig test src/main.zig",
+			"command": "$(find zig-cache -name test) src/main.zig",
 			"group": {
 				"kind": "test",
 				"isDefault": true

src/io.zig

@@ -10,7 +10,7 @@ pub const Writer = struct {
     writeContext: fn (*anyopaque, []const u8) usize,
 
     ///
-    ///
+    /// Radices supported by [writeInt].
     ///
     pub const Radix = enum {
         binary,
@@ -79,8 +79,8 @@ pub const Writer = struct {
         const Int = @TypeOf(value);
         const type_info = @typeInfo(Int);
 
-        if (type_info != .Int) @compileError("value must be of type int");
+        switch (type_info) {
-
+            .Int => {
                 if (value == 0) return writer.writeByte('0');
 
                 // TODO: Unhardcode this as it will break with large ints.
@@ -107,11 +107,17 @@ pub const Writer = struct {
                     std.mem.swap(u8, &buffer[i], &buffer[buffer_count - i - 1]);
 
                 return (writer.write(buffer[0 .. buffer_count]) == buffer_count);
+            },
+
+            // Cast comptime int into known-size integer and try again.
+            .ComptimeInt => return writer.
+                writeInt(radix, @intCast(std.math.IntFittingRange(value, value), value)),
+
+            else => @compileError("value must be of type int"),
+        }
     }
 };
 
-var null_context = @as(usize, 0);
-
 ///
 /// Writer that silently throws consumed data away and never fails.
 ///
@@ -119,13 +125,10 @@ var null_context = @as(usize, 0);
 /// sent somewhere for whatever reason.
 ///
 pub const null_writer = Writer{
-    .context = (&null_context),
+    .context = undefined,
-
-    .operation = struct {
-        fn write(context: *anyopaque, buffer: []const u8) usize {
-            // Validate context canary value.
-            std.debug.assert(@ptrCast(*usize, @alignCast(@alignOf(usize), context)).* == 0);
 
+    .writeContext = struct {
+        fn write(_: *anyopaque, buffer: []const u8) usize {
             return buffer.len;
         }
     }.write,
@@ -137,9 +140,9 @@ test {
     {
         const sequence = "foo";
 
-        testing.expectEqual(null_writer.write(sequence), sequence.len);
+        try testing.expectEqual(null_writer.write(sequence), sequence.len);
     }
 
-    testing.expect(null_writer.writeByte(0));
+    try testing.expect(null_writer.writeByte(0));
-    testing.expect(null_writer.writeInt(.decimal, 420));
+    try testing.expect(null_writer.writeInt(.decimal, 420));
 }

src/main.zig

@@ -15,7 +15,10 @@ pub fn main() anyerror!void {
 }
 
 test {
-
+    _ = io;
+    _ = stack;
+    _ = std;
+    _ = sys;
 }
 
 fn run(event_loop: *sys.EventLoop, graphics: *sys.GraphicsContext) anyerror!void {
@@ -38,7 +41,7 @@ fn run(event_loop: *sys.EventLoop, graphics: *sys.GraphicsContext) anyerror!void
         if ((try event_loop.readFile(file_access, buffer)) != file_size)
             return error.ScriptLoadFailure;
 
-        event_loop.log(buffer);
+        event_loop.log(.debug, buffer);
     }
 
     while (graphics.poll()) |_| {

src/stack.zig

@@ -91,7 +91,7 @@ pub const FixedPushError = error {
     Overflow,
 };
 
-test "fixed stack" {
+test {
     const testing = std.testing;
     var buffer = std.mem.zeroes([4]u8);
     var stack = Fixed(u8){.buffer = &buffer};

src/sys.zig

@@ -8,7 +8,7 @@ const stack = @import("./stack.zig");
 const std = @import("std");
 
 ///
-///
+/// A thread-safe platform abstraction over multiplexing system I/O processing and event handling.
 ///
 pub const EventLoop = opaque {
     ///
@@ -23,7 +23,7 @@ pub const EventLoop = opaque {
             exit,
 
             close: struct {
-                file_system_path: *FileAccess,
+                file_access: *FileAccess,
             },
 
             log: struct {
@@ -33,7 +33,7 @@ pub const EventLoop = opaque {
 
             open: struct {
                 mode: OpenMode,
-                path: *const FileSystem.Path,
+                file_system_path: *const FileSystem.Path,
                 result: OpenError!*FileAccess = error.NotFound,
             },
 
@@ -138,13 +138,15 @@ pub const EventLoop = opaque {
     ///
     /// Closes access to the file referenced by `file_access` via `event_loop`.
     ///
+    /// *Note* that nothing happens to `file_access` if it is already closed.
+    ///
     pub fn close(event_loop: *EventLoop, file_access: *FileAccess) void {
-        var message = FileSystemMessage{
+        var file_system_message = FileSystemMessage{
             .frame = @frame(),
             .request = .{.close = .{.file_access = file_access}},
         };
 
-        suspend event_loop.enqueueFileSystemMessage(&message);
+        suspend event_loop.enqueueFileSystemMessage(&file_system_message);
     }
 
     ///
@@ -174,7 +176,7 @@ pub const EventLoop = opaque {
     /// *Note* that `message` is not guaranteed to be partly, wholely, or at all written.
     ///
     pub fn log(event_loop: *EventLoop, kind: LogKind, message: []const u8) void {
-        var message = FileSystemMessage{
+        var file_system_message = FileSystemMessage{
             .frame = @frame(),
 
             .request = .{.log = .{
@@ -183,7 +185,7 @@ pub const EventLoop = opaque {
             }},
         };
 
-        suspend event_loop.enqueueFileSystemMessage(&message);
+        suspend event_loop.enqueueFileSystemMessage(&file_system_message);
     }
 
     ///
@@ -199,24 +201,26 @@ pub const EventLoop = opaque {
     pub fn open(event_loop: *EventLoop, mode: OpenMode,
         file_system_path: FileSystem.Path) OpenError!*FileAccess {
 
-        var message = FileSystemMessage{
+        var file_system_message = FileSystemMessage{
             .frame = @frame(),
 
-            .request = .{
+            .request = .{.open = .{
-                .open = .{
                 .mode = mode,
                 .file_system_path = &file_system_path,
-                },
+            }},
-            },
         };
 
-        suspend event_loop.enqueueFileSystemMessage(&message);
+        suspend event_loop.enqueueFileSystemMessage(&file_system_message);
 
-        return message.request.open.result;
+        return file_system_message.request.open.result;
     }
 
     ///
+    /// [FileSystemMessage] processing function used by a dedicated worker thread, where `data` is
+    /// a type-erased reference to a [EventLoop].
     ///
+    /// The processor returns `0` if it exited normally or any other value if an erroneous exit
+    /// occured.
     ///
     fn processFileSystemMessages(data: ?*anyopaque) callconv(.C) c_int {
         const implementation = Implementation.cast(@ptrCast(*EventLoop, data orelse unreachable));
@@ -266,20 +270,23 @@ pub const EventLoop = opaque {
                     },
 
                     .close => |*close_request| {
-                        // Don't care if this doesn't work.
+                        // TODO: Use this result somehow.
                         _ = ext.SDL_RWclose(@ptrCast(*ext.SDL_RWops, @alignCast(
                                 @alignOf(ext.SDL_RWops), close_request.file_access)));
                     },
 
                     .read_file => |read_request| {
+                        // TODO: Implement.
                         _ = read_request;
                     },
 
                     .seek_file => |seek_request| {
+                        // TODO: Implement.
                         _ = seek_request;
                     },
 
                     .tell_file => |tell_request| {
+                        // TODO: Implement.
                         _ = tell_request;
                     },
                 }
@@ -304,29 +311,45 @@ pub const EventLoop = opaque {
     pub fn readFile(event_loop: *EventLoop, file_access: *FileAccess,
         buffer: []const u8) FileError!usize {
 
-        var message = FileSystemMessage{
+        var file_system_message = FileSystemMessage{
             .frame = @frame(),
 
-            .request = .{
+            .request = .{.read_file = .{
-                .read_file = .{
                 .file_access = file_access,
                 .buffer = buffer,
-                },
+            }},
-            },
         };
 
-        suspend event_loop.enqueueFileSystemMessage(&message);
+        suspend event_loop.enqueueFileSystemMessage(&file_system_message);
 
-        return message.request.read_file.result;
+        return file_system_message.request.read_file.result;
     }
 
     ///
+    /// Attempts to tell the current file cursor position for the file referenced by `file_access`.
     ///
+    /// Returns the number of bytes into the file that the cursor is relative to its beginning or a
+    /// [FileError] if the file failed to be queried.
+    ///
+    pub fn queryFile(event_loop: *EventLoop, file_access: *FileAccess) FileError!usize {
+        var file_system_message = FileSystemMessage{
+            .frame = @frame(),
+            .request = .{.tell_file = .{.file_access = file_access}},
+        };
+
+        suspend event_loop.enqueueFileSystemMessage(&file_system_message);
+
+        return file_system_message.request.tell_file.result;
+    }
+
+    ///
+    /// Attempts to seek the file cursor through the file referenced by `file_access` from `origin`
+    /// to `offset` via `event_loop`, returning a [FileError] if the file failed to be sought.
     ///
     pub fn seekFile(event_loop: *EventLoop, file_access: *FileAccess,
         origin: SeekOrigin, offset: usize) FileError!void {
 
-        var message = FileSystemMessage{
+        var file_system_message = FileSystemMessage{
             .frame = @frame(),
 
             .request = .{
@@ -338,23 +361,9 @@ pub const EventLoop = opaque {
             },
         };
 
-        suspend event_loop.enqueueFileSystemMessage(&message);
+        suspend event_loop.enqueueFileSystemMessage(&file_system_message);
 
-        return message.request.seek_file.result;
+        return file_system_message.request.seek_file.result;
-    }
-
-    ///
-    ///
-    ///
-    pub fn tellFile(event_loop: *EventLoop, file_access: *FileAccess) FileError!usize {
-        var message = FileSystemMessage{
-            .frame = @frame(),
-            .request = .{.tell_file = .{.file_access = file_access}},
-        };
-
-        suspend event_loop.enqueueFileSystemMessage(&message);
-
-        return message.request.tell_file.result;
     }
 };
 
@@ -368,11 +377,11 @@ pub const FileAccess = opaque {
     ///
     pub fn size(file_access: *FileAccess, event_loop: *EventLoop) FileError!usize {
         // Save cursor to return to it later.
-        const origin_cursor = try event_loop.tellFile(file_access);
+        const origin_cursor = try event_loop.queryFile(file_access);
 
         try event_loop.seekFile(file_access, .tail, 0);
 
-        const ending_cursor = try event_loop.tellFile(file_access);
+        const ending_cursor = try event_loop.queryFile(file_access);
 
         // Return to original cursor.
         try event_loop.seekFile(file_access, .head, origin_cursor);
@@ -391,14 +400,15 @@ pub const FileError = error {
 };
 
 ///
-///
+/// Platform-agnostic mechanism for working with an abstraction of the underlying file-system(s)
+/// available to the application in a sandboxed environment.
 ///
 pub const FileSystem = enum {
     data,
     user,
 
     ///
-    /// Platform-agnostic mechanism for referencing files and directories on a [FileSystem]
+    /// Platform-agnostic mechanism for referencing files and directories on a [FileSystem].
     ///
     pub const Path = struct {
         file_system: FileSystem,