Add "task?" predicate

src/stdlib.cpp

@@ -451,6 +451,23 @@ Result<StackFrame> stdlib_task(const StackFrame& stack) {
   return res;
 }
 
+Result<StackFrame> stdlib_is_task(const StackFrame& stack) {
+  auto params = TRY(stack.get(0));
+
+  auto size = TRY(params.size());
+  if (size != 1) return ERROR(ArgumentCountMismatch);
+
+  Value task = TRY(params.get(0));
+
+  auto val = Value(TRY(Bool::create(task.is<Task>())));
+
+  auto res = TRY(stack.set(0, val));
+
+  res = TRY(res.ret(0));
+
+  return res;
+}
+
 Result<StackFrame> stdlib_guard(const StackFrame& stack) {
   auto stack_size = TRY(stack.size());
   auto params = TRY(stack.get(0));
@@ -582,34 +599,34 @@ Result<StackFrame> stdlib_disassemble(const StackFrame& stack) {
 
   return res;
 }
-#define STDLIB_FUNCTION(name, id)                                  \
-  [(uint64_t)StdlibFunctionId::id] = {#name, StdlibFunctionId::id, \
-                                      stdlib_##name}
+#define STDLIB_FUNCTION(name, fun, id) \
+  [(uint64_t)StdlibFunctionId::id] = {name, StdlibFunctionId::id, stdlib_##fun}
 
 static StdlibFunctionEntry function_entries[] = {
-    STDLIB_FUNCTION(unknown, Unknown),
-    STDLIB_FUNCTION(print, Print),
-    STDLIB_FUNCTION(println, PrintLn),
-    STDLIB_FUNCTION(prn, Prn),
-    STDLIB_FUNCTION(slurp, Slurp),
-    STDLIB_FUNCTION(spit, Spit),
-    STDLIB_FUNCTION(assert, Assert),
-    STDLIB_FUNCTION(dict, Dict),
-    STDLIB_FUNCTION(list, List),
-    STDLIB_FUNCTION(array, Array),
-    STDLIB_FUNCTION(get, Get),
-    STDLIB_FUNCTION(set, Set),
-    STDLIB_FUNCTION(srcloc, SrcLoc),
-    STDLIB_FUNCTION(size, Size),
-    STDLIB_FUNCTION(map, Map),
-    STDLIB_FUNCTION(error, Error),
-    STDLIB_FUNCTION(raise, Raise),
-    STDLIB_FUNCTION(reraise, Reraise),
-    STDLIB_FUNCTION(task, Task),
-    STDLIB_FUNCTION(guard, Guard),
-    STDLIB_FUNCTION(serialize, Serialize),
-    STDLIB_FUNCTION(deserialize, Deserialize),
-    STDLIB_FUNCTION(disassemble, Disassemble),
+    STDLIB_FUNCTION("unknown", unknown, Unknown),
+    STDLIB_FUNCTION("print", print, Print),
+    STDLIB_FUNCTION("println", println, PrintLn),
+    STDLIB_FUNCTION("prn", prn, Prn),
+    STDLIB_FUNCTION("slurp", slurp, Slurp),
+    STDLIB_FUNCTION("spit", spit, Spit),
+    STDLIB_FUNCTION("assert", assert, Assert),
+    STDLIB_FUNCTION("dict", dict, Dict),
+    STDLIB_FUNCTION("list", list, List),
+    STDLIB_FUNCTION("array", array, Array),
+    STDLIB_FUNCTION("get", get, Get),
+    STDLIB_FUNCTION("set", set, Set),
+    STDLIB_FUNCTION("srcloc", srcloc, SrcLoc),
+    STDLIB_FUNCTION("size", size, Size),
+    STDLIB_FUNCTION("map", map, Map),
+    STDLIB_FUNCTION("error", error, Error),
+    STDLIB_FUNCTION("raise", raise, Raise),
+    STDLIB_FUNCTION("reraise", reraise, Reraise),
+    STDLIB_FUNCTION("task", task, Task),
+    STDLIB_FUNCTION("task?", is_task, IsTask),
+    STDLIB_FUNCTION("guard", guard, Guard),
+    STDLIB_FUNCTION("serialize", serialize, Serialize),
+    STDLIB_FUNCTION("deserialize", deserialize, Deserialize),
+    STDLIB_FUNCTION("disassemble", disassemble, Disassemble),
     [(uint64_t)StdlibFunctionId::Max] = {0, StdlibFunctionId::Max,
                                          stdlib_unknown},
 };

src/stdlib.hpp

@@ -24,6 +24,7 @@ enum class StdlibFunctionId : uint64_t {
   Raise,
   Reraise,
   Task,
+  IsTask,
   Guard,
   Serialize,
   Deserialize,