10 files changed, 282 insertions, 0 deletions

diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/baseref.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/baseref.hpp
new file mode 100644
index 0000000..84c9c13
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/baseref.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "common.hpp"
+#include "../level-1/ref.hpp"
+#include "statementref.hpp"
+
+namespace intellect {
+namespace level2 {
+
+template <typename ref>
+struct baseref : public level1::baseref<ref>
+{
+	using level1::baseref<ref>::baseref;
+	baseref(level1::ref other) : level1::baseref<ref>(other.ptr()) { }
+	operator level1::ref() { return ptr(); }
+
+	statementref operator=(ref other) { return assignop(self, other); }
+	statementref operator,(ref other) { return commaop(self, other); }
+	ref operator[](ref other) { return subop(self, other); }
+}
+
+}
+}
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/common.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/common.hpp
new file mode 100644
index 0000000..25c8026
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/common.hpp
@@ -0,0 +1,9 @@
+#pragma once
+
+namespace intellect {
+namespace level2 {
+
+struct ref;
+
+}
+}
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/concepts.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/concepts.hpp
new file mode 100644
index 0000000..20c5ad4
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/concepts.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+#include "../level-1/concepts.hpp"
+
+namespace intellect {
+namespace level2 {
+
+namespace concepts {
+
+using namespace level1::concepts;
+
+static	decl(variable),
+	decl(expression),
+	decl(assign),
+	decl(comma),
+	decl(subscript),
+	decl(action),
+	decl(statement),
+	decl(left),
+	decl(right),
+	decl(operand);
+
+}
+
+}
+}
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/funcs.cpp b/starts/meaning-vm/level-2-wip-stmtexprs/funcs.cpp
new file mode 100644
index 0000000..d746f13
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/funcs.cpp
@@ -0,0 +1,69 @@
+#include "funcs.hpp"
+
+using namespace intellect;
+using namespace level2;
+using namespace concepts;
+
+static ref refassigned(ref expr)
+{
+	ref lhs = ref.get(left-operand);
+	ref rhs = ref.get(right-operand);
+	if (lhs.isa(link) && lhs.get(link-target) == unknown) {
+		// completes the target of a link, for a[b] = c
+		lhs.unlink(link-target, unknown);
+		lhs.set(link-target, rhs);
+		ref.unlink(right-operand, rhs);
+		ref src = lhs.get(link-source);
+		if (lhs.get(link-type) != unknown && src != unknown) {
+			src.set(lhs.get(link-type), rhs);
+			return src;
+		} else {
+			throw std::logic_error("not sure what to do with incomplete link assignment");
+		}
+	} else if (isanonymous(rhs) && !isanonymous(lhs)) {
+		// assignment of anonymous content to empty named concept
+		ref.unlink(left-operand, lhs);
+		return level1::movetoname(rhs, lhs);
+	} else {
+		throw std::logic_error("unexpected bare assignment");
+	}
+}
+// maybe later we can have ref class itself do operators completely based on its own
+// ref content.
+
+statementref assignop(ref self, ref other)
+{
+	return statementref::makebinary(
+		self, concepts::assign, other,
+		refassigned, refassigned
+	);
+}
+statementref commaop(ref self, ref other)
+{
+	if (self.isa(comma-expression)) {
+		if (other.isa(comma-expression)) {
+			for (auto & l : other.links()) { self.insert(l.first, l.second); }
+			dealloc(other);
+		} else {
+			self.link(topic, other);
+		}
+		return self;
+	} else if (other.isa(comma-expression)) {
+		other.link(topic, self);
+		return other;
+	} else {
+		return statementcallref::makebinary(
+			self, comma, other,
+			[](ref)->ref { return ref; },
+			// um when we pass the comma-expression to
+			// the [] operator that takes a ref
+			// the destructor of statementref will deallocate it.
+			[](ref) { throw std::logic_error("bare comma-expression"); }
+			// something is wrong here.  some approach is wrong.
+			// would it be better to have ref itself do it all?
+		);
+	}
+}
+ref subop(ref self, ref other)
+{
+}
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/funcs.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/funcs.hpp
new file mode 100644
index 0000000..6af6ce1
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/funcs.hpp
@@ -0,0 +1,14 @@
+#pragma once
+
+#include "common.hpp"
+#include "../level-1/ref.hpp"
+
+namespace intellect {
+namespace level2 {
+
+statementref commaop(ref self, ref other);
+statementref assignop(ref self, ref other);
+ref subop(ref self, ref other);
+
+}
+}
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/meaning.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/meaning.hpp
new file mode 100644
index 0000000..049e7f9
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/meaning.hpp
@@ -0,0 +1,42 @@
+#pragma once
+
+#include "ref.hpp"
+#include "../level-1/helpers.hpp"
+
+namespace intellect {
+namespace level2 {
+
+// get a named variable
+ref avariable(ref name);
+
+template <typename... T>
+ref and(T... refs)
+{
+	std::initializer_list<ref> rs = { refs... };
+	decl(and, topic);
+	ref ret = a(and);
+	ref name; int count = 0;
+	for (auto r : rs) {
+		ret.link(topic, r);
+		if (count == 0) {
+			name.ptr() = r.ptr();
+		} else {
+			name.ptr() = (name-and-r).ptr();
+		}
+		++ count;
+	}
+	if (count == 1) {
+		throw std::invalid_argument("and needs at least two subjects");
+	}
+	// in level-1, we'll want to name anonymous objects after defining them
+	return name = ret;
+}
+
+// make a reference to a link
+ref link(ref sourceref, ref typeref, ref targetref);
+
+// invert a meaning
+ref not(ref whatref);
+
+}
+}
diff --git a/starts/meaning-vm/level-2/ref.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/ref.hpp
index 5b7dc4f..5b7dc4f 100644
--- a/starts/meaning-vm/level-2/ref.hpp
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/ref.hpp
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/statementref.cpp b/starts/meaning-vm/level-2-wip-stmtexprs/statementref.cpp
new file mode 100644
index 0000000..2f23dc8
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/statementref.cpp
@@ -0,0 +1,68 @@
+#include "statementref.hpp"
+
+#include "concepts.hpp"
+#include "ref.hpp"
+
+using namespace intellect;
+using namespace level2;
+using namespace concepts;
+
+// so, anonymous-assignment is both a statement and an expression.
+// multiple-member-assignment is only an expression: it is an error to evaluate it
+// the submember operator will be both a statement and an expression, but doesn't need to be held as a ref
+// single-member-assignment is mostly a statement: using it as an expression should be an error.
+
+static statementref makebinary(
+	ref lhs, ref kind, ref rhs,
+	std::function<ref(ref)> expraction,
+	std::function<void(ref)> stmtaction
+)
+{
+	a(statement-expresion, kind-expression);
+	ref r = a(kind-expression);
+	r.set(left-operand, lhs);
+	r.set(right-operand, rhs);
+	r.vset(expression-action, expraction);
+	r.vset(statement-action, stmtaction);
+	return r;
+}
+
+statementref::statementref(ref r)
+: r(r.ptr())
+{
+	if (!r.isa(statement-expression)) {
+		throw std::logic_error("that is not a statement expression");
+	}
+}
+
+static void de(ref & r)
+{
+	ref lhs, rhs, expraction, stmtaction;
+
+	try { lhs = r.get(left-operand); } catch(level0::no_such_link_type&) {}
+	try { rhs = r.get(right-operand); } catch(level0::no_such_link_type&) {}
+
+	expraction = r.get(expression-action);
+	stmtaction = r.get(statement-action);
+	dealloc(r);
+	if (lhs != nothing) { dealloc(lhs); }
+	if (rhs != nothing) { dealloc(rhs); }
+	dealloc(expraction);
+	dealloc(stmtaction);
+	r = 0;
+}
+
+statementref::~statementref()
+{
+	if (r == 0) { return; }
+	r.vget<std::function<void(ref)>>(statement-action)(r);
+	de(r);
+}
+
+statementref::operator ref()
+{
+	if (r == 0) { throw std::logic_error("doubly evaluated expression"); }
+	auto ret = r.vget<std::function<void(ref)>>(expression-action)(r);
+	de(r);
+	return ret;
+}
diff --git a/starts/meaning-vm/level-2-wip-stmtexprs/statementref.hpp b/starts/meaning-vm/level-2-wip-stmtexprs/statementref.hpp
new file mode 100644
index 0000000..502ecf4
--- /dev/null
+++ b/starts/meaning-vm/level-2-wip-stmtexprs/statementref.hpp
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "common.hpp"
+#include "../level-0/concept.hpp"
+
+namespace intellect {
+namespace level2 {
+
+// this class is returned by some of the baseref operators.
+// its purpose is to evaluate code when it goes out of
+// scope, so as to facilitate syntactic behavior.
+struct statementref
+{
+	statementref(ref r);
+	statementref(statementref const &) = delete;
+	~statementref();
+
+	operator ref();
+
+	static statementref makebinary(
+		ref lhs, ref kind, ref rhs,
+		std::function<ref(ref)> expraction = {},
+		std::function<void(ref)> stmtaction = {}
+	);
+
+private:
+	level0::concept * r;
+};
+
+}
+}
diff --git a/starts/meaning-vm/level-2/common.hpp b/starts/meaning-vm/level-2/common.hpp
deleted file mode 100644
index e69de29..0000000
--- a/starts/meaning-vm/level-2/common.hpp
+++ /dev/null