Tidy up Kym implementation

source/kym/kym.zig

@@ -144,10 +144,7 @@ pub const Vm = struct {
 		}
 	},
 
-	pub const CompileError = error {
+	pub const CompileError = bytecode.ParseError;
-		BadSyntax,
-		OutOfMemory,
-	};
 
 	const HeapAllocation = union(enum) {
 		next_free: u32,

source/kym/tokens.zig

@@ -33,6 +33,22 @@ pub const Token = union(enum) {
 	keyword_return,
 	keyword_self,
 
+	pub const ExpectError = error {
+		UnexpectedToken,
+	};
+
+	pub fn expect(self: Token, tag: coral.io.Tag(Token)) ExpectError!void {
+		if (self != tag) return error.UnexpectedToken;
+	}
+
+	pub fn expect_any(self: Token, tags: []const coral.io.Tag(Token)) ExpectError!void {
+		for (tags) |tag| {
+			if (self == tag) return;
+		}
+
+		return error.UnexpectedToken;
+	}
+
 	pub fn text(self: Token) []const u8 {
 		return switch (self) {
 			.unknown => |unknown| @ptrCast([*]const u8, &unknown)[0 .. 1],
@@ -64,6 +80,7 @@ pub const Token = union(enum) {
 			.keyword_false => "false",
 			.keyword_true => "true",
 			.keyword_return => "return",
+			.keyword_self => "self",
 		};
 	}
 };
@@ -72,8 +89,12 @@ pub const Tokenizer = struct {
 	source: []const u8,
 	cursor: usize = 0,
 
+	pub fn has_next(self: Tokenizer) bool {
+		return self.cursor < self.source.len;
+	}
+
 	pub fn next(self: *Tokenizer) ?Token {
-		while (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+		while (self.has_next()) switch (self.source[self.cursor]) {
 			' ', '\t' => self.cursor += 1,
 
 			'\n' => {
@@ -87,13 +108,13 @@ pub const Tokenizer = struct {
 
 				self.cursor += 1;
 
-				while (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+				while (self.has_next()) switch (self.source[self.cursor]) {
 					'0' ... '9' => self.cursor += 1,
 
 					'.' => {
 						self.cursor += 1;
 
-						while (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+						while (self.has_next()) switch (self.source[self.cursor]) {
 							'0' ... '9' => self.cursor += 1,
 							else => break,
 						};
@@ -136,13 +157,13 @@ pub const Tokenizer = struct {
 			'@' => {
 				self.cursor += 1;
 
-				if (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+				if (self.has_next()) switch (self.source[self.cursor]) {
 					'A'...'Z', 'a'...'z', '_' => {
 						const begin = self.cursor;
 
 						self.cursor += 1;
 
-						while (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+						while (self.has_next()) switch (self.source[self.cursor]) {
 							'0'...'9', 'A'...'Z', 'a'...'z', '_' => self.cursor += 1,
 							else => break,
 						};
@@ -157,7 +178,7 @@ pub const Tokenizer = struct {
 
 						self.cursor += 1;
 
-						while (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+						while (self.has_next()) switch (self.source[self.cursor]) {
 							'"' => break,
 							else => self.cursor += 1,
 						};
@@ -180,7 +201,7 @@ pub const Tokenizer = struct {
 
 				self.cursor += 1;
 
-				while (self.cursor < self.source.len) switch (self.source[self.cursor]) {
+				while (self.has_next()) switch (self.source[self.cursor]) {
 					'"' => break,
 					else => self.cursor += 1,
 				};