1 files changed, 142 insertions, 0 deletions
diff --git a/cpp/045closure_name b/cpp/045closure_name
new file mode 100644
index 00000000..76a1bdd7
--- /dev/null
+++ b/cpp/045closure_name
@@ -0,0 +1,142 @@
+//: Writing to a literal (not computed) address of 0 in a recipe chains two
+//: spaces together. When a variable has a property of /space:1, it looks up
+//: the variable in the chained/surrounding space. /space:2 looks up the
+//: surrounding space of the surrounding space, etc.
+:(scenario "closure")
+recipe main [
+  default-space:address:space <- new location:type, 30:literal
+  1:address:space/names:init-counter <- init-counter
+#?   $print [AAAAAAAAAAAAAAAA]
+#?   $print 1:address:space
+  2:integer/raw <- increment-counter 1:address:space/names:init-counter
+  3:integer/raw <- increment-counter 1:address:space/names:init-counter
+]
+
+recipe init-counter [
+  default-space:address:space <- new location:type, 30:literal
+  x:integer <- copy 23:literal
+  y:integer <- copy 3:literal  # variable that will be incremented
+  reply default-space:address:space
+]
+
+recipe increment-counter [
+  default-space:address:space <- new space:literal, 30:literal
+  0:address:space/names:init-counter <- next-ingredient  # outer space must be created by 'init-counter' above
+  y:integer/space:1 <- add y:integer/space:1, 1:literal  # increment
+  y:integer <- copy 234:literal  # dummy
+  reply y:integer/space:1
+]
+
++name: recipe increment-counter is surrounded by init-counter
++mem: storing 5 in location 3
+
+//: To make this work, compute the recipe that provides names for the
+//: surrounding space of each recipe. This must happen before transform_names.
+:(before "End Globals")
+unordered_map<recipe_number, recipe_number> Surrounding_space;
+
+:(after "int main")
+  Transform.push_back(collect_surrounding_spaces);
+
+:(code)
+void collect_surrounding_spaces(const recipe_number r) {
+  for (size_t i = 0; i < Recipe[r].steps.size(); ++i) {
+    const instruction& inst = Recipe[r].steps[i];
+    if (inst.is_label) continue;
+    for (size_t j = 0; j < inst.products.size(); ++j) {
+      if (isa_literal(inst.products[j])) continue;
+      if (inst.products[j].name != "0") continue;
+      if (inst.products[j].types.size() != 2
+          || inst.products[j].types[0] != Type_number["address"]
+          || inst.products[j].types[1] != Type_number["space"]) {
+        raise << "slot 0 should always have type address:space, but is " << inst.products[j].to_string() << '\n';
+        continue;
+      }
+      vector<string> s = property(inst.products[j], "names");
+      if (s.empty())
+        raise << "slot 0 requires a /names property in recipe " << Recipe[r].name << die();
+      if (s.size() > 1) raise << "slot 0 should have a single value in /names, got " << inst.products[j].to_string() << '\n';
+      string surrounding_recipe_name = s[0];
+      if (Surrounding_space.find(r) != Surrounding_space.end()
+          && Surrounding_space[r] != Recipe_number[surrounding_recipe_name]) {
+        raise << "recipe " << Recipe[r].name << " can have only one 'surrounding' recipe but has " << Recipe[Surrounding_space[r]].name << " and " << surrounding_recipe_name << '\n';
+        continue;
+      }
+      trace("name") << "recipe " << Recipe[r].name << " is surrounded by " << surrounding_recipe_name;
+      Surrounding_space[r] = Recipe_number[surrounding_recipe_name];
+    }
+  }
+}
+
+vector<string> property(const reagent& r, const string& name) {
+  for (size_t p = 0; p != r.properties.size(); ++p) {
+    if (r.properties[p].first == name)
+      return r.properties[p].second;
+  }
+  return vector<string>();
+}
+
+//: Once surrounding spaces are available, transform_names uses them to handle
+//: /space properties.
+
+:(replace{} "size_t lookup_name(const reagent& r, const recipe_number default_recipe)")
+size_t lookup_name(const reagent& x, const recipe_number default_recipe) {
+//?   cout << "AAA " << default_recipe << " " << Recipe[default_recipe].name << '\n'; //? 2
+//?   cout << "AAA " << x.to_string() << '\n'; //? 1
+  if (!has_property(x, "space")) {
+    if (Name[default_recipe].empty()) raise << "name not found: " << x.name << '\n' << die();
+    return Name[default_recipe][x.name];
+  }
+  vector<string> p = property(x, "space");
+  if (p.size() != 1) raise << "/space property should have exactly one (non-negative integer) value\n";
+  int n = to_int(p[0]);
+  assert(n >= 0);
+  recipe_number surrounding_recipe = lookup_surrounding_recipe(default_recipe, n);
+  set<recipe_number> done;
+  vector<recipe_number> path;
+  return lookup_name(x, surrounding_recipe, done, path);
+}
+
+// If the recipe we need to lookup this name in doesn't have names done yet,
+// recursively call transform_names on it.
+size_t lookup_name(const reagent& x, const recipe_number r, set<recipe_number>& done, vector<recipe_number>& path) {
+  if (!Name[r].empty()) return Name[r][x.name];
+  if (done.find(r) != done.end()) {
+    raise << "can't compute address of " << x.to_string() << " because ";
+    for (size_t i = 1; i < path.size(); ++i) {
+      raise << path[i-1] << " requires computing names of " << path[i] << '\n';
+    }
+    raise << path[path.size()-1] << " requires computing names of " << r << "..ad infinitum\n" << die();
+    return 0;
+  }
+  done.insert(r);
+  path.push_back(r);
+  transform_names(r);  // Not passing 'done' through. Might this somehow cause an infinite loop?
+  assert(!Name[r].empty());
+  return Name[r][x.name];
+}
+
+recipe_number lookup_surrounding_recipe(const recipe_number r, size_t n) {
+  if (n == 0) return r;
+  if (Surrounding_space.find(r) == Surrounding_space.end()) {
+    raise << "don't know surrounding recipe of " << Recipe[r].name << '\n';
+    return 0;
+  }
+  assert(Surrounding_space[r]);
+  return lookup_surrounding_recipe(Surrounding_space[r], n-1);
+}
+
+//: weaken use-before-set warnings just a tad
+:(replace{} "bool already_transformed(const reagent& r, const unordered_map<string, int>& names)")
+bool already_transformed(const reagent& r, const unordered_map<string, int>& names) {
+  if (has_property(r, "space")) {
+    vector<string> p = property(r, "space");
+    assert(p.size() == 1);
+    if (p[0] != "0") return true;
+  }
+  return names.find(r.name) != names.end();
+}
+
+:(before "End Includes")
+#include<set>
+using std::set;