From 5c08a1b63ef326210702cf74ce0b2379d009688a Mon Sep 17 00:00:00 2001
From: kayomn <kayomn@kayomn.net>
Date: Sat, 26 Aug 2023 21:30:36 +0100
Subject: [PATCH] Add lambda argument arity checking to runtime

---
 debug/app.ona      |  2 ++
 source/ona/kym.zig | 39 +++++++++++++++++++++++----------------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/debug/app.ona b/debug/app.ona
index dddd91f..855cf63 100644
--- a/debug/app.ona
+++ b/debug/app.ona
@@ -6,6 +6,8 @@ let pr = lambda (str):
 	@print(str)
 end
 
+pr("eeee")
+
 while i < 5:
 	pr("hello, world")
 
diff --git a/source/ona/kym.zig b/source/ona/kym.zig
index 2a865c8..1a34fc1 100644
--- a/source/ona/kym.zig
+++ b/source/ona/kym.zig
@@ -18,6 +18,7 @@ pub const RuntimeEnv = struct {
 	const Chunk = struct {
 		env: *RuntimeEnv,
 		name: []coral.io.Byte,
+		arity: u8,
 		opcodes: OpcodeList,
 		constants: ConstList,
 
@@ -141,11 +142,15 @@ pub const RuntimeEnv = struct {
 					},
 
 					.lambda_literal => |literal| {
-						if (literal.argument_identifiers.values.len > coral.math.max_int(@typeInfo(u32).Int)) {
+						if (literal.argument_identifiers.values.len > coral.math.max_int(@typeInfo(u8).Int)) {
 							return error.OutOfMemory;
 						}
 
-						var lambda_chunk = try Chunk.make(chunk.env, "<lambda>");
+						var lambda_chunk = try Chunk.make(
+							chunk.env,
+							"<lambda>",
+							@intCast(literal.argument_identifiers.values.len),
+						);
 
 						errdefer lambda_chunk.free();
 
@@ -982,11 +987,12 @@ pub const RuntimeEnv = struct {
 			self.env.allocator.deallocate(self.name);
 		}
 
-		fn make(env: *RuntimeEnv, name: []const coral.io.Byte) coral.io.AllocationError!Chunk {
+		fn make(env: *RuntimeEnv, name: []const coral.io.Byte, arity: u8) coral.io.AllocationError!Chunk {
 			return .{
 				.name = try coral.io.allocate_copy(env.allocator, name),
 				.opcodes = OpcodeList.make(env.allocator),
 				.constants = ConstList.make(env.allocator),
+				.arity = arity,
 				.env = env,
 			};
 		}
@@ -996,7 +1002,13 @@ pub const RuntimeEnv = struct {
 		}
 
 		fn typeinfo_call(method: Typeinfo.Method) RuntimeError!?*RuntimeRef {
-			return @as(*Chunk, @ptrCast(@alignCast(method.userdata))).execute();
+			const chunk = @as(*Chunk, @ptrCast(@alignCast(method.userdata)));
+
+			if ((method.env.view_args() catch unreachable).len < chunk.arity) {
+				return method.env.raise(error.BadOperation, "expected more arguments");
+			}
+
+			return chunk.execute();
 		}
 
 		fn typeinfo_destruct(method: Typeinfo.Method) void {
@@ -1122,7 +1134,6 @@ pub const RuntimeEnv = struct {
 				method.env.discard(replaced.value);
 			}
 		}
-
 	};
 
 	pub fn acquire(self: *RuntimeEnv, value: *const RuntimeRef) RuntimeError!*RuntimeRef {
@@ -1147,16 +1158,6 @@ pub const RuntimeEnv = struct {
 		return null;
 	}
 
-	pub fn acquire_args(self: *RuntimeEnv) RuntimeError!*RuntimeRef {
-		const frame = self.frames.peek() orelse return self.raise(error.IllegalState, "stack underflow");
-
-		_ = frame;
-
-		const args_table = self.new_table();
-
-		return args_table;
-	}
-
 	pub fn call(self: *RuntimeEnv, callable: *RuntimeRef, args: []const *RuntimeRef) RuntimeError!?*RuntimeRef {
 		try self.locals.push_all(args);
 
@@ -1222,7 +1223,7 @@ pub const RuntimeEnv = struct {
 		defer self.allocator.deallocate(file_data);
 
 		const file_name = file_path.to_string() orelse "<script>";
-		var chunk = try Chunk.make(self, file_name);
+		var chunk = try Chunk.make(self, file_name, 0);
 
 		defer chunk.free();
 
@@ -1539,6 +1540,12 @@ pub const RuntimeEnv = struct {
 			else => env.raise(error.TypeMismatch, "expected symbol object")
 		};
 	}
+
+	pub fn view_args(self: *RuntimeEnv) RuntimeError![]const ?*const RuntimeRef {
+		const frame = self.frames.peek() orelse return self.raise(error.IllegalState, "stack underflow");
+
+		return self.locals.values[(frame.locals_top - frame.arg_count) ..];
+	}
 };
 
 pub const RuntimeError = coral.io.AllocationError || error {