Clean up core library.

source/app.cpp

@@ -2,7 +2,7 @@ export module app;
 
 import core;
 import core.image;
-import core.math;
+import core.lalgebra;
 
 export namespace app {
 	struct path {
@@ -32,8 +32,8 @@ export namespace app {
 			return 0;
 		}
 
-		bool equals(path const & that) {
+		bool equals(path const & that) const {
-			return core::equals(this->as_slice(), that.as_slice());
+			return core::equals(this->as_slice().as_bytes(), that.as_slice().as_bytes());
 		}
 
 		constexpr path joined(core::slice<char const> const & text) const {

source/app/sdl.cpp

@@ -9,19 +9,24 @@ import app;
 import core;
 import core.image;
 import core.sequence;
-import core.math;
+import core.lalgebra;
 
 struct bundled_file_store : public app::file_store {
 	void read_file(app::path const & file_path, core::callable<void(core::readable const &)> const & then) override {
-		// Path is guaranteed to never be greater than 512 characters long (file_path is max 256 and prefix is 2).
+		constexpr core::slice<char const> path_prefix = "./";
-		core::stack<char, 512> path_buffer{&core::null_allocator()};
+		constexpr core::usize path_max = 512;
 
-		if (path_buffer.append("./").has_value()) core::unreachable();
+		if ((file_path.size() + path_prefix.length) > path_max) core::unreachable();
+
+		core::stack<char, path_max> path_buffer{&core::null_allocator()};
+
+		if (path_buffer.append("./") != core::append_result::ok) core::unreachable();
 
 		// File path is guaranteed to be null-terminated.
-		if (path_buffer.append(file_path.as_slice()).has_value()) core::unreachable();
+		if (path_buffer.append(file_path.as_slice()) != core::append_result::ok)
+			core::unreachable();
 
-		SDL_RWops * rw_ops = ::SDL_RWFromFile(path_buffer.as_slice().pointer, "r");
+		SDL_RWops * rw_ops = ::SDL_RWFromFile(path_buffer.begin(), "r");
 
 		if (rw_ops == nullptr) return;
 

source/core.cpp

@@ -5,6 +5,20 @@ module;
 
 export module core;
 
+// Runtime utilities.
+export namespace core {
+	/**
+	 * Triggers safety-checked behavior in debug mode.
+	 *
+	 * In release mode, the compiler can use this function as a marker to optimize out safety-
+	 * checked logic branches that should never be executed.
+	 */
+	[[noreturn]] void unreachable() {
+		__builtin_unreachable();
+	}
+}
+
+// Concrete and interface types.
 export namespace core {
 	using usize = size_t;
 
@@ -36,119 +50,231 @@ export namespace core {
 
 	using f64 = double;
 
+	/**
+	 * Base type for runtime-pluggable memory allocation strategies used by the core library.
+	 */
 	struct allocator {
-		allocator() = default;
-
-		allocator(allocator const &) = delete;
-
 		virtual ~allocator() {};
 
-		virtual u8 * reallocate(u8 * maybe_allocation, usize requested_size) = 0;
+		/**
+		 * If `allocation` is `nullptr`, the allocator will attempt to allocate a new memory block
+		 * of `requested_size` bytes. Otherwise, the allocator will attempt to reallocate
+		 * `allocation` to be `request_size` bytes in size.
+		 *
+		 * The returned address will point to a dynamically allocated buffer of `requested_size` if
+		 * the operation was successful, otherwise `nullptr`.
+		 *
+		 * *Note*: If the returned address is a non-`nullptr`, it should be deallocated prior to
+		 * program exit. This may be achieved through either [deallocate] or implementation-
+		 * specific allocator functionality.
+		 *
+		 * *Note*: Attempting to pass a non-`nullptr` `allocation` address not allocated by the
+		 * allocator *will* result in erroneous implementation-behavior.
+		 *
+		 * *Note*: After invocation, `allocation` should be considered an invalid memory address.
+		 */
+		[[nodiscard]] virtual u8 * reallocate(u8 * allocation, usize requested_size) = 0;
 
+		/**
+		 * If `allocation` points to a non-`nullptr` address, the allocator will deallocate it.
+		 * Otherwise, the function has no side-effects.
+		 *
+		 * *Note* that attempting to pass a non-`nullptr` `allocation` address not allocated by the
+		 * allocator *will* result in erroneous implementation-behavior.
+		 */
 		virtual void deallocate(void * allocation) = 0;
 	};
-}
-
-export void * operator new(core::usize requested_size, core::u8 * allocation_placement) {
-	return allocation_placement;
-}
-
-export void * operator new[](core::usize requested_size, core::u8 * allocation_placement) {
-	return allocation_placement;
-}
-
-export void * operator new(core::usize requested_size, core::allocator & allocator) {
-	return allocator.reallocate(nullptr, requested_size);
-}
-
-export void * operator new[](core::usize requested_size, core::allocator & allocator) {
-	return allocator.reallocate(nullptr, requested_size);
-}
-
-export namespace core {
-	[[noreturn]] void unreachable() {
-		__builtin_unreachable();
-	}
-
-	template<typename scalar> constexpr scalar max(scalar const & a, scalar const & b) {
-		return (a > b) ? a : b;
-	}
-
-	template<typename scalar> constexpr scalar min(scalar const & a, scalar const & b) {
-		return (a < b) ? a : b;
-	}
-
-	template<typename scalar> constexpr scalar clamp(scalar const & value, scalar const & min_value, scalar const & max_value) {
-		return max(min_value, min(max_value, value));
-	}
-
-	f32 round32(f32 value) {
-		return __builtin_roundf(value);
-	}
 
+	/**
+	 * Length-signed pointer type that describes how many elements of `type` it references,
+	 * providing a type-safe wrapper for passing arrays and zero-terminated strings to functions.
+	 */
 	template<typename type> struct slice {
+		/**
+		 * Number of `type` elements referenced.
+		 */
 		usize length;
 
+		/**
+		 * Base element address referenced.
+		 */
 		type * pointer;
 
-		constexpr slice() : length{0}, pointer{nullptr} {
+		constexpr slice() {
-
+			this->length = 0;
+			this->pointer = nullptr;
 		}
 
-		constexpr slice(char const *&& zstring) : length{0}, pointer{zstring} {
+		constexpr slice(char const *&& zstring) {
+			this->pointer = zstring;
+			this->length = 0;
+
 			while (zstring[length] != 0) this->length += 1;
 		}
 
-		constexpr slice(type * slice_pointer, usize slice_length) : length{slice_length}, pointer{slice_pointer} {
+		constexpr slice(type * slice_pointer, usize slice_length) {
-
+			this->pointer = slice_pointer;
+			this->length = slice_length;
 		}
 
-		template<usize array_size> constexpr slice(type(&array)[array_size]) : length{array_size}, pointer{array} {
+		constexpr slice(type * slice_begin, type * slice_end) {
-
+			this->pointer = slice_begin;
+			this->length = static_cast<usize>(slice_end - slice_begin);
 		}
 
+		template<usize array_size> constexpr slice(type(&array)[array_size]) {
+			this->pointer = array;
+			this->length = array_size;
+		}
+
+		/**
+		 * Reinterprets the data referenced as a series of bytes.
+		 *
+		 * The returned view is constant to protect against inadvertant memory corruption.
+		 */
 		slice<u8 const> as_bytes() const {
 			return {reinterpret_cast<u8 const *>(this->pointer), this->length * sizeof(type)};
 		}
 
+		/**
+		 * Reinterprets the data referenced as a series of chars.
+		 *
+		 * The returned view is constant to protect against inadvertant memory corruption.
+		 *
+		 * *Note* the returned value has no guarantees about the validity of any specific character
+		 * encoding set.
+		 */
 		slice<char const> as_chars() const {
 			return {reinterpret_cast<char const *>(this->pointer), this->length * sizeof(type)};
 		}
 
+		/**
+		 * Returns the base pointer of the slice.
+		 */
+		constexpr type * begin() const {
+			return this->pointer;
+		}
+
+		/**
+		 * Returns the tail pointer of the slice.
+		 */
+		constexpr type * end() const {
+			return this->pointer + this->length;
+		}
+
+		/**
+		 * Returns a new slice with the base-pointer offset by `index` elements and a length of
+		 * `range` elements from `index`.
+		 *
+		 * *Note* that attempting to slice with an `index` or `range` outside of the existing slice
+		 * bounds will result in safety-checked behavior.
+		 */
+		constexpr slice sliced(usize index, usize range) const {
+			if ((this->length <= index) || ((range + index) > this->length)) unreachable();
+
+			return {this->pointer + index, range - index};
+		}
+
 		operator slice<type const>() const {
 			return (*reinterpret_cast<slice<type const> const *>(this));
 		}
 
-		type & operator[](usize index) const {
+		constexpr type & operator[](usize index) const {
+			if (this->length <= index) core::unreachable();
+
 			return this->pointer[index];
 		}
-
-		slice<type> after(usize index) const {
-			return {this->pointer + index, this->length - index};
-		}
-
-		slice<type> until(usize index) const {
-			return {this->pointer, index};
-		}
-
-		slice<type> between(usize a, usize b) const {
-			return {this->pointer + a, b};
-		}
-
-		constexpr type * begin() const {
-			return this->pointer;
-		}
-
-		constexpr type * end() const {
-			return this->pointer + this->length;
-		}
 	};
+}
 
-	template<typename element> struct [[nodiscard]] optional {
+// Math functions.
-		optional() : buffer{0} {
+export namespace core {
-
+	/**
+	 * Returns the maximum value between `a` and `b`.
+	 */
+	template<typename scalar> constexpr scalar max(scalar const & a, scalar const & b) {
+		return (a > b) ? a : b;
 	}
 
+	/**
+	 * Returns the minimum value between `a` and `b`.
+	 */
+	template<typename scalar> constexpr scalar min(scalar const & a, scalar const & b) {
+		return (a < b) ? a : b;
+	}
+
+	/**
+	 * Returns `value` clamped between the range of `min_value` and `max_value` (inclusive).
+	 */
+	template<typename scalar> constexpr scalar clamp(scalar const & value, scalar const & min_value, scalar const & max_value) {
+		return max(min_value, min(max_value, value));
+	}
+
+	/**
+	 * Returns `value` rounded to the nearest whole number.
+	 */
+	f32 round32(f32 value) {
+		return __builtin_roundf(value);
+	}
+}
+
+/**
+ * Allocates and initializes a type of `requested_size` in `buffer`, returning its base pointer. As
+ * a result of accepting a pre-allocated buffer, invocation does not allocate any dynamic memory.
+ *
+ * *Note*: passing an `buffer` smaller than `requested_size` will result in safety-checked
+ * behavior.
+ */
+export void * operator new(core::usize requested_size, core::slice<core::u8> const & buffer) {
+	if (buffer.length < requested_size) core::unreachable();
+
+	return buffer.pointer;
+}
+
+/**
+ * Allocates and initializes a series of types at `requested_size` in `buffer`, returning the base
+ * pointer. As a result of accepting a pre-allocated buffer, invocation does not allocate any
+ * dynamic memory.
+ *
+ * *Note*: passing an `buffer` smaller than `requested_size` will result in safety-checked
+ * behavior.
+ */
+export void * operator new[](core::usize requested_size, core::slice<core::u8> const & buffer) {
+	if (buffer.length < requested_size) core::unreachable();
+
+	return buffer.pointer;
+}
+
+/**
+ * Attempts to allocate and initialize a type of `requested_size` using `allocator`.
+ *
+ * *Note*: If the returned address is a non-`nullptr`, it should be deallocated prior to program
+ * exit. This may be achieved through either [core::allocator::deallocate] or implementation-
+ * specific allocator functionality.
+ */
+export [[nodiscard]] void * operator new(core::usize requested_size, core::allocator & allocator) {
+	return allocator.reallocate(nullptr, requested_size);
+}
+
+/**
+ * Attempts to allocate and initialize a series of types of `requested_size` using `allocator`.
+ *
+ * *Note*: If the returned address is a non-`nullptr`, it should be deallocated prior to program
+ * exit. This may be achieved through either [core::allocator::deallocate] or implementation-
+ * specific allocator functionality.
+ */
+export [[nodiscard]] void * operator new[](core::usize requested_size, core::allocator & allocator) {
+	return allocator.reallocate(nullptr, requested_size);
+}
+
+// Wrapper types.
+export namespace core {
+	/**
+	 * Monadic container for a single-`element` value or nothing.
+	 */
+	template<typename element> struct [[nodiscard]] optional {
+		optional() : buffer{0} {}
+
 		optional(element const & value) : buffer{0} {
 			(*reinterpret_cast<element *>(this->buffer)) = value;
 			this->buffer[sizeof(element)] = 1;
@@ -163,18 +289,38 @@ export namespace core {
 			}
 		}
 
+		/**
+		 * Returns `true` if the optional contains a value, otherwise `false`.
+		 */
 		bool has_value() const {
 			return this->buffer[sizeof(element)] == 1;
 		}
 
+		/**
+		 * Returns the contained value or `fallback` if the optional is empty.
+		 */
 		element const & value_or(element const & fallback) const {
 			return this->has_value() ? *reinterpret_cast<element const *>(this->buffer) : fallback;
 		}
 
+		/**
+		 * Returns a reference to the contained value.
+		 *
+		 * *Note*: attempting to access the value of an empty optional will trigger safety-checked
+		 * behavior.
+		 */
 		element & value() {
+			if (!this->has_value()) unreachable();
+
 			return *reinterpret_cast<element *>(this->buffer);
 		}
 
+		/**
+		 * Returns the contained value.
+		 *
+		 * *Note*: attempting to access the value of an empty optional will trigger safety-checked
+		 * behavior.
+		 */
 		element const & value() const {
 			return *reinterpret_cast<element const *>(this->buffer);
 		}
@@ -183,6 +329,9 @@ export namespace core {
 		u8 buffer[sizeof(element) + 1];
 	};
 
+	/**
+	 * Monadic container for a descriminating union of either `value_element` or `error_element`.
+	 */
 	template<typename value_element, typename error_element> struct [[nodiscard]] expected {
 		expected(value_element const & value) : buffer{0} {
 			(*reinterpret_cast<value_element *>(this->buffer)) = value;
@@ -193,28 +342,55 @@ export namespace core {
 			(*reinterpret_cast<error_element *>(this->buffer)) = error;
 		}
 
+		/**
+		 * Returns `true` if the optional contains a value, otherwise `false` if it holds an error.
+		 */
 		bool is_ok() const {
 			return this->buffer[buffer_size];
 		}
 
+		/**
+		 * Returns a reference to the contained value.
+		 *
+		 * *Note*: attempting to access the value of an erroneous expected will trigger safety-
+		 * checked behavior.
+		 */
 		value_element & value() {
 			if (!this->is_ok()) unreachable();
 
 			return *reinterpret_cast<value_element *>(this->buffer);
 		}
 
+		/**
+		 * Returns the contained value.
+		 *
+		 * *Note*: attempting to access the value of an erroneous expected will trigger safety-
+		 * checked behavior.
+		 */
 		value_element const & value() const {
 			if (!this->is_ok()) unreachable();
 
 			return *reinterpret_cast<value_element const *>(this->buffer);
 		}
 
+		/**
+		 * Returns a reference to the contained error.
+		 *
+		 * *Note*: attempting to access the error of a non-erroneous expected will trigger safety-
+		 * checked behavior.
+		 */
 		error_element & error() {
 			if (this->is_ok()) unreachable();
 
 			return *reinterpret_cast<error_element *>(this->buffer);
 		}
 
+		/**
+		 * Returns the contained error.
+		 *
+		 * *Note*: attempting to access the error of a non-erroneous expected will trigger safety-
+		 * checked behavior.
+		 */
 		error_element const & error() const {
 			if (this->is_ok()) unreachable();
 
@@ -229,39 +405,120 @@ export namespace core {
 
 	template<typename> struct callable;
 
-	template<typename return_type, typename... argument_types> struct callable<return_type(argument_types...)> {
+	/**
-		using function = return_type(*)(argument_types...);
+	 * Type-erasing wrapper for functor types that have a call operator with a return value
+	 * matching `return_value` and arguments matching `argument_values`.
+	 */
+	template<typename return_value, typename... argument_values> struct callable<return_value(argument_values...)> {
+		using function = return_value(*)(argument_values...);
+
+		callable(function callable_function) {
+			this->dispatcher = [](u8 const * userdata, argument_values... arguments) -> return_value {
+				return (*reinterpret_cast<function const *>(userdata))(arguments...);
+			};
 
-		callable(function callable_function) : dispatcher(dispatch_function) {
 			new (this->capture) function{callable_function};
 		}
 
 		callable(callable const &) = delete;
 
-		template<typename functor> callable(functor const & callable_functor) : dispatcher(dispatch_functor<functor>) {
+		template<typename functor> callable(functor const & callable_functor) {
+			this->dispatcher = [](u8 const * userdata, argument_values... arguments) -> return_value {
+				return (*reinterpret_cast<functor const*>(userdata))(arguments...);
+			};
+
 			new (this->capture) functor{callable_functor};
 		}
 
-		return_type operator()(argument_types const &... arguments) const {
+		return_value operator()(argument_values const &... arguments) const {
 			return this->dispatcher(this->capture, arguments...);
 		}
 
 		private:
 		static constexpr usize capture_size = 24;
 
-		return_type(* dispatcher)(u8 const * userdata, argument_types... arguments);
+		return_value(* dispatcher)(u8 const * userdata, argument_values... arguments);
 
 		u8 capture[capture_size];
-
-		static return_type dispatch_function(u8 const * userdata, argument_types... arguments) {
-			return (*reinterpret_cast<function const *>(userdata))(arguments...);
-		}
-
-		template<typename functor_type> static return_type dispatch_functor(u8 const * userdata, argument_types... arguments) {
-			return (*reinterpret_cast<functor_type const*>(userdata))(arguments...);
-		}
 	};
 
+	/**
+	 * Errors that may occur while executing an opaque I/O operation via the `readable` and
+	 * `writable` type aliases.
+	 */
+	enum class io_error {
+		unavailable,
+	};
+
+	using readable = callable<expected<usize, io_error>(slice<u8> const &)>;
+
+	using writable = callable<expected<usize, io_error>(slice<u8 const> const &)>;
+}
+
+// Input/output operations.
+export namespace core {
+	/**
+	 * Tests the equality of `a` against `b`, returning `true` if they contain identical bytes,
+	 * otherwise `false`.
+	 */
+	bool equals(slice<u8 const> const & a, slice<u8 const> const & b) {
+		if (a.length != b.length) return false;
+
+		for (size_t i = 0; i < a.length; i += 1) if (a[i] != b[i]) return false;
+
+		return true;
+	}
+
+	/**
+	 * Copies the contents of `origin` into `target`.
+	 *
+	 * *Note*: safety-checked behavior is triggered if `target` is smaller than `origin`.
+	 */
+	void copy(slice<u8> const & target, slice<u8 const> const & origin) {
+		if (target.length < origin.length) core::unreachable();
+
+		for (usize i = 0; i < origin.length; i += 1) target[i] = origin[i];
+	}
+
+	/**
+	 * Streams the data from `input` to `output`, using `buffer` as temporary transfer space.
+	 *
+	 * The returned [expected] can be used to introspect if `input` or `output` encountered any
+	 * issues during streaming, otherwise it will contain the number of bytes streamed.
+	 *
+	 * *Note*: if `buffer` has a length of `0`, no data will be streamed as there is nowhere to
+	 * temporarily place data during streaming.
+	 */
+	expected<usize, io_error> stream(writable const & output,
+		readable const & input, slice<u8> const & buffer) {
+
+		usize written = 0;
+		expected maybe_read = input(buffer);
+
+		if (!maybe_read.is_ok()) return maybe_read.error();
+
+		usize read = maybe_read.value();
+
+		while (read != 0) {
+			expected const maybe_written = output(buffer.sliced(0, read));
+
+			if (!maybe_written.is_ok()) return maybe_read.error();
+
+			written += maybe_written.value();
+			maybe_read = input(buffer);
+
+			if (!maybe_read.is_ok()) return maybe_read.error();
+
+			read = maybe_read.value();
+		}
+
+		return written;
+	}
+
+	/**
+	 * Returns a reference to a shared [allocator] which will always return `nullptr` on calls to
+	 * [allocator::reallocate].
+	 */
 	allocator & null_allocator() {
 		static struct : public allocator {
 			u8 * reallocate(u8 * maybe_allocation, usize requested_size) override {
@@ -277,44 +534,4 @@ export namespace core {
 
 		return a;
 	}
-
-	enum class io_error {
-		unavailable,
-	};
-
-	using readable = callable<expected<usize, io_error>(slice<u8> const &)>;
-
-	using writable = callable<expected<usize, io_error>(slice<u8 const> const &)>;
-
-	template<typename element_type> bool equals(slice<element_type const> const & a, slice<element_type const> const & b) {
-		if (a.length != b.length) return false;
-
-		for (size_t i = 0; i < a.length; i += 1) if (a[i] != b[i]) return false;
-
-		return true;
-	}
-
-	expected<usize, io_error> stream(writable const & output, readable const & input, slice<u8> const & buffer) {
-		usize written = 0;
-		expected maybe_read = input(buffer);
-
-		if (!maybe_read.is_ok()) return maybe_read.error();
-
-		usize read = maybe_read.value();
-
-		while (read != 0) {
-			expected const maybe_written = output(buffer.until(read));
-
-			if (!maybe_written.is_ok()) return maybe_read.error();
-
-			written += maybe_written.value();
-			maybe_read = input(buffer);
-
-			if (!maybe_read.is_ok()) return maybe_read.error();
-
-			read = maybe_read.value();
-		}
-
-		return written;
-	}
 }

source/core/image.cpp

@@ -3,27 +3,54 @@ export module core.image;
 import core;
 
 export namespace core {
+	/**
+	 * All-purpose color value for red, green, blue, alpha channel-encoded values.
+	 */
 	struct color {
+		/**
+		 * Red channel.
+		 */
 		float r;
 
+		/**
+		 * Green channel.
+		 */
 		float g;
 
+		/**
+		 * Blue channel.
+		 */
 		float b;
 
+		/**
+		 * Alpha channel.
+		 */
 		float a;
 
+		/**
+		 * Red channel represented in an 8-bit unsigned value.
+		 */
 		u8 to_r8() const {
 			return static_cast<u8>(round32(clamp(this->r, 0.0f, 1.0f) * u8_max));
 		}
 
+		/**
+		 * Green channel represented in an 8-bit unsigned value.
+		 */
 		u8 to_g8() const {
 			return static_cast<u8>(round32(clamp(this->g, 0.0f, 1.0f) * u8_max));
 		}
 
+		/**
+		 * Blue channel represented in an 8-bit unsigned value.
+		 */
 		u8 to_b8() const {
 			return static_cast<u8>(round32(clamp(this->b, 0.0f, 1.0f) * u8_max));
 		}
 
+		/**
+		 * Alpha channel represented in an 8-bit unsigned value.
+		 */
 		u8 to_a8() const {
 			return static_cast<u8>(round32(clamp(this->a, 0.0f, 1.0f) * u8_max));
 		}

source/core/lalgebra.cpp

@@ -0,0 +1,40 @@
+export module core.lalgebra;
+
+import core;
+
+export namespace core {
+	/**
+	 * Two-component vector type backed by 32-bit floating point values.
+	 */
+	struct vector2 {
+		/**
+		 * "X" axis spatial component.
+		 */
+		f32 x;
+
+		/**
+		 * "Y" axis spatial component.
+		 */
+		f32 y;
+	};
+
+	/**
+	 * Three-component vector type backed by 32-bit floating point values.
+	 */
+	struct vector3 {
+		/**
+		 * "X" axis spatial component.
+		 */
+		f32 x;
+
+		/**
+		 * "Y" axis spatial component.
+		 */
+		f32 y;
+
+		/**
+		 * "Z" axis spatial component.
+		 */
+		f32 z;
+	};
+}

source/core/math.cpp

@@ -1,19 +0,0 @@
-export module core.math;
-
-import core;
-
-export namespace core {
-	struct vector2 {
-		core::f32 x;
-
-		core::f32 y;
-	};
-
-	struct vector3 {
-		core::f32 x;
-
-		core::f32 y;
-
-		core::f32 z;
-	};
-}

source/core/sequence.cpp

@@ -3,116 +3,212 @@ export module core.sequence;
 import core;
 
 export namespace core {
-	enum class reserve_error {
+	/**
+	 * Result codes used by [sequence]-derived types when they are appended to in any way.
+	 *
+	 * [append_result::ok] indicates that an append operation was successful.
+	 *
+	 * [append_result::out_of_memory] alerts that the memory required to perform the append
+	 * operation failed.
+	 */
+	enum class [[nodiscard]] append_result {
+		ok,
 		out_of_memory,
 	};
 
+	/**
+	 * Base type for all sequence-like types.
+	 *
+	 * Sequences are any data structure which owns a linear, non-unique set of elements which may
+	 * be queried and/or mutated.
+	 */
 	template<typename element> struct sequence {
-		sequence() = default;
-
-		sequence(sequence const &) = delete;
-
 		virtual ~sequence() {};
 
-		virtual slice<element const> as_slice() const = 0;
+		/**
-
+		 * Attempts to append `source_elements` to the sequence.
-		virtual optional<reserve_error> append(slice<element const> const & appended_elements) = 0;
+		 *
+		 * The returned [append_result] indicates whether the operation was successful or not.
+		 *
+		 * If the returned [append_result] is anything but [append_result::ok], the [sequence] will
+		 * be left in an implementation-defined state.
+		 */
+		virtual append_result append(slice<element const> const & source_elements) = 0;
 	};
 
-	template<typename element, usize initial_capacity = 1> struct stack : public sequence<element> {
+	/**
-		stack(allocator * buffer_allocator) : filled{0},
+	 * Last-in-first-out linear sequence of `element` values.
-			buffer{0}, buffer_allocator{buffer_allocator} {
+	 *
-
+	 * [stack] types will default to using an inline array of `init_capacity` at first. After all
-			this->elements = this->buffer;
+	 * local storage has been exhausted, the [stack] will switch to a dynamic buffer. Because of
+	 * this, it is recommended to use larger `init_capacity` values for data which has a known or
+	 * approximate upper bound at compile-time. Otherwise, the `init_capacity` value may be left at
+	 * its default.
+	 */
+	template<typename element, usize init_capacity = 1> struct stack : public sequence<element> {
+		stack(allocator * dynamic_allocator) : local_buffer{0} {
+			this->dynamic_allocator = dynamic_allocator;
+			this->filled = 0;
+			this->elements = this->local_buffer;
 		}
 
 		~stack() override {
-			if (this->elements.pointer != this->buffer)
+			if (this->is_dynamic()) this->dynamic_allocator->deallocate(this->elements.pointer);
-				this->buffer_allocator->deallocate(this->elements.pointer);
 		}
 
-		slice<element const> as_slice() const override {
+		/**
-			return this->elements;
+		 * Attempts to append `source_elements` to the top of the stack.
-		}
+		 *
-
+		 * The returned [append_result] indicates whether the operation was successful or not.
-		optional<reserve_error> push(element const & pushed_element) {
+		 *
-			if (this->filled == this->elements.length) {
+		 * If the returned [append_result] is anything but [append_result::ok], the stack will be
-				optional const maybe_error = this->reserve(this->elements.length);
+		 * be left in an empty but valid state.
-
+		 *
-				if (maybe_error.has_value()) return maybe_error;
+		 * *Note* that [push] is recommended when appending singular values.
-			}
+		 */
-
+		append_result append(slice<element const> const & source_elements) override {
-			this->elements[this->filled] = pushed_element;
+			usize const updated_fill = this->filled + source_elements.length;
-			this->filled += 1;
-
-			return {};
-		}
-
-		optional<reserve_error> append(slice<element const> const & pushed_elements) override {
-			usize const updated_fill = this->filled + pushed_elements.length;
 
 			if (updated_fill >= this->elements.length) {
-				optional const maybe_error = this->reserve(max(this->elements.length, updated_fill));
+				append_result const result =
+					this->reserve(max(this->elements.length, updated_fill));
 
-				if (maybe_error.has_value()) return maybe_error;
+				if (result != append_result::ok) return result;
 			}
 
-			for (usize i = 0; i < pushed_elements.length; i += 1)
+			for (usize i = 0; i < source_elements.length; i += 1)
-				this->elements[this->filled + i] = pushed_elements[i];
+				this->elements[this->filled + i] = source_elements[i];
 
 			this->filled = updated_fill;
 
-			return {};
+			return append_result::ok;
 		}
 
-		optional<reserve_error> reserve(usize capacity) {
+		/**
+		 * Returns the beginning of the elements as a mutable pointer.
+		 */
+		element * begin() {
+			return this->elements.pointer;
+		}
+
+		/**
+		 * Returns the beginning of the elements as a const pointer.
+		 */
+		element const * begin() const {
+			return this->elements.pointer;
+		}
+
+		/**
+		 * Returns the ending of the elements as a mutable pointer.
+		 */
+		element * end() {
+			return this->elements.pointer + this->filled;
+		}
+
+		/**
+		 * Returns the ending of the elements as a const pointer.
+		 */
+		element const * end() const {
+			return this->elements.pointer + this->filled;
+		}
+
+		/**
+		 * Returns `true` if the stack is backed by dynamic memory, otherwise `false`.
+		 */
+		bool is_dynamic() const {
+			return this->elements.pointer != this->local_buffer;
+		}
+
+		/**
+		 * Attempts to append `source_element` to the top of the stack.
+		 *
+		 * The returned [append_result] indicates whether the operation was successful or not.
+		 *
+		 * If the returned [append_result] is anything but [append_result::ok], the stack will be
+		 * be left in an empty but valid state.
+		 *
+		 * *Note* that [append] is recommended when appending many values at once.
+		 */
+		append_result push(element const & source_element) {
+			if (this->filled == this->elements.length) {
+				append_result const result = this->reserve(this->elements.length);
+
+				if (result != append_result::ok) return result;
+			}
+
+			this->elements[this->filled] = source_element;
+			this->filled += 1;
+
+			return append_result::ok;
+		}
+
+		/**
+		 * Attempts to reserve `capacity` number of elements additional space on the stack, forcing
+		 * it to use dynamic memory _even_ if it hasn't exhausted the local buffer yet.
+		 *
+		 * The returned [append_result] indicates whether the operation was successful or not.
+		 *
+		 * If the returned [append_result] is anything but [append_result::ok], the stack will be
+		 * be left in an empty but valid state.
+		 *
+		 * *Note* that manual invocation is not recommended if the [stack] has a large
+		 * `initial_capacity` argument.
+		 */
+		append_result reserve(usize capacity) {
 			usize const requested_capacity = this->elements.length + capacity;
 
-			if (this->elements.pointer == this->buffer) {
+			if (this->is_dynamic()) {
-				u8 * const maybe_allocation = this->buffer_allocator->
+				// Grow dynamic buffer (bailing out if failed).
-					reallocate(nullptr, sizeof(element) * requested_capacity);
+				u8 * const buffer = this->dynamic_allocator->reallocate(
-
-				if (maybe_allocation == nullptr) {
-					this->elements = {};
-
-					return reserve_error::out_of_memory;
-				}
-
-				this->elements = {reinterpret_cast<element *>(maybe_allocation), requested_capacity};
-			} else {
-				u8 * const maybe_allocation = this->buffer_allocator->reallocate(
 					reinterpret_cast<u8 *>(this->elements.pointer),
 						sizeof(element) * requested_capacity);
 
-				if (maybe_allocation == nullptr) {
+				if (buffer == nullptr) {
 					this->elements = {};
 
-					return reserve_error::out_of_memory;
+					return append_result::out_of_memory;
 				}
 
-				this->elements = {reinterpret_cast<element *>(maybe_allocation), requested_capacity};
+				this->elements = {reinterpret_cast<element *>(buffer), requested_capacity};
+			} else {
+				usize const buffer_size = sizeof(element) * requested_capacity;
+				u8 * const buffer = this->dynamic_allocator->reallocate(nullptr, buffer_size);
+
+				if (buffer == nullptr) {
+					this->elements = {};
+
+					return append_result::out_of_memory;
 				}
 
-			return {};
+				core::copy({buffer, buffer_size}, this->elements.as_bytes());
+
+				this->elements = {reinterpret_cast<element *>(buffer), requested_capacity};
+			}
+
+			return append_result::ok;
 		}
 
 		private:
-		allocator * buffer_allocator;
+		allocator * dynamic_allocator;
 
 		usize filled;
 
 		slice<element> elements;
 
-		element buffer[initial_capacity];
+		element local_buffer[init_capacity];
 	};
 
+	/**
+	 * Writable type for appending data to a [sequence] containing [u8] values.
+	 */
 	struct sequence_writer : public writable {
-		sequence_writer(sequence<u8> * target_sequence) : writable{[target_sequence](slice<u8 const> const & buffer) -> expected<usize, io_error> {
+		sequence_writer(sequence<u8> * output_sequence) : writable{
-			optional const maybe_error = target_sequence->append(buffer);
+			[output_sequence](slice<u8 const> const & buffer) -> expected<usize, io_error> {
-
+				switch (output_sequence->append(buffer)) {
-			if (maybe_error.has_value()) return io_error::unavailable;
+					case append_result::ok: return buffer.length;
-
+					case append_result::out_of_memory: return io_error::unavailable;
-			return buffer.length;
+					default: unreachable();
+				}
 			}} {}
 	};
 }

source/kym.cpp

@@ -1,7 +1,7 @@
 export module kym;
 
 import core;
-import core.math;
+import core.lalgebra;
 
 export namespace kym {
 	enum class value_type {

source/kym/environment.cpp

@@ -5,6 +5,8 @@ import core.sequence;
 
 import kym;
 
+using loggable = core::callable<void(core::slice<char const> const &)>;
+
 export namespace kym {
 	struct vm;
 }
@@ -42,7 +44,7 @@ struct bytecode {
 
 	}
 
-	bool compile(tokenizer bytecode_tokenizer) {
+	bool compile(tokenizer bytecode_tokenizer, loggable const & log_error) {
 		for (;;) {
 			token const initial_token = bytecode_tokenizer.next();
 
@@ -58,10 +60,6 @@ struct bytecode {
 		return kym::nil;
 	}
 
-	core::slice<char const> error_message() const {
-		return this->error_message_buffer.as_slice();
-	}
-
 	private:
 	core::stack<char> error_message_buffer;
 };
@@ -71,8 +69,8 @@ export namespace kym {
 		return nil;
 	}
 
-	core::expected<core::usize, core::io_error> default_stringify(vm & owning_vm, void * userdata, core::writable const & writable) {
+	core::expected<core::usize, core::io_error> default_stringify(vm & owning_vm, void * userdata, core::writable const & output) {
-		return writable(core::slice("[object]").as_bytes());
+		return output(core::slice("[object]").as_bytes());
 	}
 
 	struct bound_object {
@@ -100,8 +98,8 @@ export namespace kym {
 			return this->behavior.call(*this->owning_vm, this->userdata, arguments);
 		}
 
-		core::expected<core::usize, core::io_error> stringify(core::writable const & writable) {
+		core::expected<core::usize, core::io_error> stringify(core::writable const & output) {
-			return this->behavior.stringify(*this->owning_vm, this->userdata, writable);
+			return this->behavior.stringify(*this->owning_vm, this->userdata, output);
 		}
 
 		value get_field(core::slice<char const> const & field_name) {
@@ -143,8 +141,9 @@ export namespace kym {
 
 			if (source_bytecode == nullptr) return nil;
 
-			if (source_bytecode->compile(tokenizer{source})) {
+			if (!source_bytecode->compile(tokenizer{source}, [&](core::slice<char const> error_message) {
-				this->log(source_bytecode->error_message());
+				this->log(error_message);
+			})) {
 				this->allocator->deallocate(source_bytecode);
 
 				return nil;
@@ -176,7 +175,7 @@ export namespace kym {
 		private:
 		core::slice<value> data_stack;
 
-		core::callable<void(core::slice<char const>)> log;
+		loggable log;
 
 		core::allocator * allocator;
 	};

source/runtime.cpp

@@ -4,7 +4,7 @@ import app;
 import app.sdl;
 
 import core;
-import core.math;
+import core.lalgebra;
 import core.sequence;
 
 import kym;
@@ -15,7 +15,7 @@ extern "C" int main(int argc, char const * const * argv) {
 		constexpr app::path config_path = app::path::empty().joined("config.kym");
 		bool is_config_loaded = false;
 
-		system.bundle().read_file(config_path, [&](core::readable const & config_readable) {
+		system.bundle().read_file(config_path, [&](core::readable const & file) {
 			kym::vm vm{&system.thread_safe_allocator(), [&system](core::slice<char const> const & error_message) {
 				system.log(app::log_level::error, error_message);
 			}};
@@ -29,14 +29,14 @@ extern "C" int main(int argc, char const * const * argv) {
 				return;
 			}
 
-			core::stack<core::u8> config_source{&system.thread_safe_allocator()};
+			core::stack<core::u8> script_source{&system.thread_safe_allocator()};
-			core::u8 config_source_stream_buffer[1024] = {};
+			core::u8 stream_buffer[1024] = {};
 
-			if (!core::stream(core::sequence_writer{&config_source},
+			if (!core::stream(core::sequence_writer{&script_source}, file, stream_buffer).is_ok())
-				config_readable, config_source_stream_buffer).is_ok()) return;
+				return;
 
-			vm.with_object(vm.compile(config_source.as_slice().as_chars()), [&](kym::bound_object & config_script) {
+			vm.with_object(vm.compile(core::slice{script_source.begin(), script_source.end()}.as_chars()), [&](kym::bound_object & script) {
-				vm.with_object(config_script.call({}), [&](kym::bound_object & config) {
+				vm.with_object(script.call({}), [&](kym::bound_object & config) {
 					core::u16 const width = config.get_field("width").as_u16().value_or(0);
 
 					if (width == 0) return system.log(app::log_level::error,