Add while loops

debug/app.ona

@@ -1,28 +1,15 @@
 
-# Test comment.
+i = 0
 
-pos = @vec3(10, 20, 0.3)
-coord = pos.xz
+while i < 5 do
+	@print("hello, world")
 
-options = {
-	.title = "Afterglow",
+	i = i + 1
+end
+
+return {
+	.title = "Game",
 	.width = 1280,
 	.height = 800,
 	.tick_rate = 60,
-
-	["foo"] = "bar",
-	[42] = "42",
 }
-
-if pos.y > 0 do
-	options["foo"] = "rab"
-	options[42] = "24"
-
-	@print("Conditional hit!")
-end
-
-@print(options.title)
-@print(options["foo"])
-@print(options[42])
-
-return options

source/ona/kym.zig

@@ -203,21 +203,23 @@ pub const RuntimeEnv = struct {
 
 					.local_get => |local_get| {
 						try chunk.opcodes.push_one(.{
-							.push_local = self.resolve_local(local_get) orelse {
+							.push_local = self.resolve_local(local_get.identifier) orelse {
 								return chunk.env.raise(error.OutOfMemory, "undefined local");
 							},
 						});
 					},
 
 					.local_set => |local_set| {
-						if (self.resolve_local(local_set)) |index| {
+						try self.compile_expression(chunk, local_set.value_expression.*);
+
+						if (self.resolve_local(local_set.identifier)) |index| {
 							try chunk.opcodes.push_one(.{.local_set = index});
 						} else {
 							if (self.local_identifiers_count == self.local_identifiers_buffer.len) {
 								return chunk.env.raise(error.BadSyntax, "chunks may have a maximum of 255 locals");
 							}
 
-							self.local_identifiers_buffer[self.local_identifiers_count] = local_set;
+							self.local_identifiers_buffer[self.local_identifiers_count] = local_set.identifier;
 							self.local_identifiers_count += 1;
 						}
 					},
@@ -268,11 +270,29 @@ pub const RuntimeEnv = struct {
 						}
 					},
 
+					.@"while" => |@"while"| {
+						try self.compile_expression(chunk, @"while".condition_expression);
+						try chunk.opcodes.push_one(.{.jf = 0});
+
+						const origin_index = @as(u32, @intCast(chunk.opcodes.values.len - 1));
+
+						for (@"while".block_statements.values) |block_statement| {
+							try self.compile_statement(chunk, block_statement);
+						}
+
+						coral.debug.assert(chunk.opcodes.values.len < coral.math.max_int(@typeInfo(u32).Int));
+
+						chunk.opcodes.values[origin_index].jf = @intCast(chunk.opcodes.values.len - 1);
+
+						try self.compile_expression(chunk, @"while".condition_expression);
+						try chunk.opcodes.push_one(.{.jt = origin_index});
+					},
+
 					.@"if" => |@"if"| {
 						try self.compile_expression(chunk, @"if".condition_expression);
 						try chunk.opcodes.push_one(.{.jf = 0});
 
-						const jump_opcode_index = chunk.opcodes.values.len - 1;
+						const origin_index = @as(u32, @intCast(chunk.opcodes.values.len - 1));
 
 						for (@"if".block_statements.values) |block_statement| {
 							try self.compile_statement(chunk, block_statement);
@@ -280,7 +300,7 @@ pub const RuntimeEnv = struct {
 
 						coral.debug.assert(chunk.opcodes.values.len < coral.math.max_int(@typeInfo(u32).Int));
 
-						chunk.opcodes.values[jump_opcode_index].jf = @intCast(chunk.opcodes.values.len - 1);
+						chunk.opcodes.values[origin_index].jf = @intCast(chunk.opcodes.values.len - 1);
 					},
 
 					.expression => |expression| try self.compile_expression(chunk, expression),
@@ -357,6 +377,10 @@ pub const RuntimeEnv = struct {
 					},
 
 					.push_local => |push_local| {
+						if (push_local >= self.env.locals.values.len) {
+							return self.env.raise(error.IllegalState, "invalid local");
+						}
+
 						if (self.env.locals.values[push_local]) |local| {
 							try self.env.locals.push_one(try self.env.acquire(local));
 						} else {

source/ona/kym/ast.zig

@@ -73,8 +73,15 @@ pub const Expression = union (enum) {
 	symbol_literal: []const coral.io.Byte,
 	table_literal: TableLiteral,
 	grouped_expression: *Expression,
-	local_get: []const coral.io.Byte,
-	local_set: []const coral.io.Byte,
+
+	local_get: struct {
+		identifier: []const coral.io.Byte,
+	},
+
+	local_set: struct {
+		identifier: []const coral.io.Byte,
+		value_expression: *Expression,
+	},
 
 	field_get: struct {
 		object_expression: *Expression,
@@ -114,7 +121,7 @@ pub const Expression = union (enum) {
 		argument_expressions: ExpressionList,
 	},
 
-	pub const TableLiteral = coral.list.Stack(struct {
+	const TableLiteral = coral.list.Stack(struct {
 		key_expression: Expression,
 		value_expression: Expression,
 	});
@@ -134,12 +141,14 @@ pub const Statement = union (enum) {
 		expression: ?Expression,
 	},
 
-	@"if": struct {
+	@"if": ConditionalBlock,
+	@"while": ConditionalBlock,
+	expression: Expression,
+
+	const ConditionalBlock = struct {
 		condition_expression: Expression,
 		block_statements: StatementList,
-	},
-
-	expression: Expression,
+	};
 };
 
 pub const StatementList = coral.list.Stack(Statement);
@@ -218,7 +227,12 @@ pub const Tree = struct {
 			}
 
 			return switch (expression) {
-				.local_get => |local_get| .{.local_set = local_get},
+				.local_get => |local_get| .{
+					.local_set = .{
+						.identifier = local_get.identifier,
+						.value_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
+					},
+				},
 
 				.field_get => |field_get| .{
 					.field_set = .{
@@ -299,7 +313,7 @@ pub const Tree = struct {
 				.identifier => |identifier| {
 					self.tokenizer.skip_newlines();
 
-					break: parse .{.local_get = identifier};
+					break: parse .{.local_get = .{.identifier = identifier}};
 				},
 
 				.builtin => |builtin| {
@@ -542,13 +556,40 @@ pub const Tree = struct {
 						break: parse_statement .{.@"return" = .{.expression = null}};
 					},
 
+					.keyword_while => {
+						self.tokenizer.step();
+
+						const condition_expression = try self.parse_expression();
+
+						if (self.tokenizer.token != .keyword_do) {
+							return self.report("expected `do` block after `while` statement");
+						}
+
+						self.tokenizer.step();
+
+						const while_statement = Statement{
+							.@"while" = .{
+								.block_statements = try self.parse_statements(),
+								.condition_expression = condition_expression,
+							},
+						};
+
+						if (self.tokenizer.token != .keyword_end) {
+							return self.report("expected `end` after block");
+						}
+
+						self.tokenizer.skip_newlines();
+
+						break: parse_statement while_statement;
+					},
+
 					.keyword_if => {
 						self.tokenizer.step();
 
 						const condition_expression = try self.parse_expression();
 
 						if (self.tokenizer.token != .keyword_do) {
-							return self.report("expected `do` block after if statement");
+							return self.report("expected `do` block after `if` statement");
 						}
 
 						self.tokenizer.step();

source/ona/kym/tokens.zig

@@ -41,6 +41,7 @@ pub const Token = union(enum) {
 	keyword_if,
 	keyword_do,
 	keyword_end,
+	keyword_while,
 
 	pub fn text(self: Token) []const coral.io.Byte {
 		return switch (self) {
@@ -85,6 +86,7 @@ pub const Token = union(enum) {
 			.keyword_if => "if",
 			.keyword_do => "do",
 			.keyword_end => "end",
+			.keyword_while => "while",
 		};
 	}
 };
@@ -243,6 +245,14 @@ pub const Tokenizer = struct {
 							}
 						},
 
+						'w' => {
+							if (coral.io.ends_with(identifier, "hile")) {
+								self.token = .keyword_while;
+
+								return;
+							}
+						},
+
 						else => {},
 					}