positional argument sugar for habits

1 files changed, 42 insertions, 1 deletions

diff --git a/starts/meaning-vm/level-2/funcs.cpp b/starts/meaning-vm/level-2/funcs.cpp
index c25ead2..b17d221 100644
--- a/starts/meaning-vm/level-2/funcs.cpp
+++ b/starts/meaning-vm/level-2/funcs.cpp
@@ -2,17 +2,58 @@
 
 #include "../level-1/sugar.hpp"
 #include "ref.hpp"
+#include "concepts.hpp"
 
 
 namespace intellect {
 using namespace level1;
 namespace level2 {
 
+using namespace concepts;
+
 ref context()
 {
-	static thread_local auto ctx = a("context");
+	static thread_local auto ctx = a(concepts::context);
 	return ctx;
 }
 
+ref makehabit(ref name, std::initializer_list<ref> argnames, std::function<void()> code)
+{
+	ref habit = level1::a(habit, name);
+	ref posarg = habit;
+	for (auto argname : argnames) {
+		ref nextarg = a(positional-argument);
+		nextarg.set(argument, argname);
+		posarg.set(next-positional-argument, nextarg);
+		posarg = nextarg;
+	}
+	habit.fun(code);
+	return habit;
+}
+
+ref dohabit(ref habit, std::initializer_list<ref> args)
+{
+	using namespace concepts;
+	ref posarg = habit;
+	for (ref const & arg : args) {
+		if (!posarg.linked(next-positional-argument)) {
+			throw std::invalid_argument("wrong number of arguments to habit");
+		}
+		posarg = posarg[next-positional-argument];
+		// TODO: subcontexts
+		ref::context().set(posarg[argument], arg);
+	}
+	if (posarg.linked(next-positional-argument)) {
+		throw std::invalid_argument("wrong number of arguments to habit");
+	}
+	ref ret = habit.fun<>()();
+	posarg = habit;
+	while (posarg.linked(next-positional-argument)) {
+		posarg = posarg[next-positional-argument];
+		ref::context().unlink(posarg[argument]);
+	}
+	return ret;
+}
+
 }
 }