2862

Layers 0-29 are now a complete rudimentary platform except for pointers
and indirection.

1 files changed, 230 insertions, 0 deletions

diff --git a/028call_reply.cc b/028call_reply.cc
new file mode 100644
index 00000000..df5fa557
--- /dev/null
+++ b/028call_reply.cc
@@ -0,0 +1,230 @@
+//: Calls can also generate products, using 'reply' or 'return'.
+
+:(scenario reply)
+def main [
+  1:number, 2:number <- f 34
+]
+def f [
+  12:number <- next-ingredient
+  13:number <- add 1, 12:number
+  reply 12:number, 13:number
+]
++mem: storing 34 in location 1
++mem: storing 35 in location 2
+
+:(before "End Primitive Recipe Declarations")
+REPLY,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "reply", REPLY);
+put(Recipe_ordinal, "return", REPLY);
+:(before "End Primitive Recipe Checks")
+case REPLY: {
+  break;  // checks will be performed by a transform below
+}
+:(before "End Primitive Recipe Implementations")
+case REPLY: {
+  // Starting Reply
+  if (Trace_stream) {
+    trace(9999, "trace") << "reply: decrementing callstack depth from " << Trace_stream->callstack_depth << end();
+    --Trace_stream->callstack_depth;
+    if (Trace_stream->callstack_depth < 0) {
+      Current_routine->calls.clear();
+      goto stop_running_current_routine;
+    }
+  }
+  Current_routine->calls.pop_front();
+  // just in case 'main' returns a value, drop it for now
+  if (Current_routine->calls.empty()) goto stop_running_current_routine;
+  const instruction& caller_instruction = current_instruction();
+  for (int i = 0; i < SIZE(caller_instruction.products); ++i)
+    trace(9998, "run") << "result " << i << " is " << to_string(ingredients.at(i)) << end();
+
+  // make reply products available to caller
+  copy(ingredients.begin(), ingredients.end(), inserter(products, products.begin()));
+  // End Reply
+  break;  // continue to process rest of *caller* instruction
+}
+
+//: Types in reply instructions are checked ahead of time.
+
+:(before "End Checks")
+Transform.push_back(check_types_of_reply_instructions);
+:(code)
+void check_types_of_reply_instructions(recipe_ordinal r) {
+  const recipe& caller = get(Recipe, r);
+  trace(9991, "transform") << "--- check types of reply instructions in recipe " << caller.name << end();
+  for (int i = 0; i < SIZE(caller.steps); ++i) {
+    const instruction& caller_instruction = caller.steps.at(i);
+    if (caller_instruction.is_label) continue;
+    if (caller_instruction.products.empty()) continue;
+    if (caller_instruction.operation < MAX_PRIMITIVE_RECIPES) continue;
+    const recipe& callee = get(Recipe, caller_instruction.operation);
+    for (int i = 0; i < SIZE(callee.steps); ++i) {
+      const instruction& reply_inst = callee.steps.at(i);
+      if (reply_inst.operation != REPLY) continue;
+      // check types with the caller
+      if (SIZE(caller_instruction.products) > SIZE(reply_inst.ingredients)) {
+        raise << maybe(caller.name) << "too few values replied from " << callee.name << '\n' << end();
+        break;
+      }
+      for (int i = 0; i < SIZE(caller_instruction.products); ++i) {
+        reagent lhs = reply_inst.ingredients.at(i);
+        reagent rhs = caller_instruction.products.at(i);
+        // End Check REPLY Copy(lhs, rhs)
+        if (!types_coercible(rhs, lhs)) {
+          raise << maybe(callee.name) << reply_inst.name << " ingredient " << lhs.original_string << " can't be saved in " << rhs.original_string << '\n' << end();
+          raise << to_string(lhs.type) << " vs " << to_string(rhs.type) << '\n' << end();
+          goto finish_reply_check;
+        }
+      }
+      // check that any reply ingredients with /same-as-ingredient connect up
+      // the corresponding ingredient and product in the caller.
+      for (int i = 0; i < SIZE(caller_instruction.products); ++i) {
+        if (has_property(reply_inst.ingredients.at(i), "same-as-ingredient")) {
+          string_tree* tmp = property(reply_inst.ingredients.at(i), "same-as-ingredient");
+          if (!tmp || tmp->right) {
+            raise << maybe(caller.name) << "'same-as-ingredient' metadata should take exactly one value in " << to_original_string(reply_inst) << '\n' << end();
+            goto finish_reply_check;
+          }
+          int ingredient_index = to_integer(tmp->value);
+          if (ingredient_index >= SIZE(caller_instruction.ingredients)) {
+            raise << maybe(caller.name) << "too few ingredients in '" << to_original_string(caller_instruction) << "'\n" << end();
+            goto finish_reply_check;
+          }
+          if (!is_dummy(caller_instruction.products.at(i)) && !is_literal(caller_instruction.ingredients.at(ingredient_index)) && caller_instruction.products.at(i).name != caller_instruction.ingredients.at(ingredient_index).name) {
+            raise << maybe(caller.name) << "'" << to_original_string(caller_instruction) << "' should write to " << caller_instruction.ingredients.at(ingredient_index).original_string << " rather than " << caller_instruction.products.at(i).original_string << '\n' << end();
+          }
+        }
+      }
+      finish_reply_check:;
+    }
+  }
+}
+
+:(scenario reply_type_mismatch)
+% Hide_errors = true;
+def main [
+  3:number <- f 2
+]
+def f [
+  12:number <- next-ingredient
+  13:number <- copy 35
+  14:point <- copy 12:point/raw
+  return 14:point
+]
++error: f: return ingredient 14:point can't be saved in 3:number
+
+//: In mu we'd like to assume that any instruction doesn't modify its
+//: ingredients unless they're also products. The /same-as-ingredient inside
+//: the recipe's 'reply' will help catch accidental misuse of such
+//: 'ingredient-products' (sometimes called in-out parameters in other languages).
+
+:(scenario reply_same_as_ingredient)
+% Hide_errors = true;
+def main [
+  1:number <- copy 0
+  2:number <- test1 1:number  # call with different ingredient and product
+]
+def test1 [
+  10:number <- next-ingredient
+  return 10:number/same-as-ingredient:0
+]
++error: main: '2:number <- test1 1:number' should write to 1:number rather than 2:number
+
+:(scenario reply_same_as_ingredient_dummy)
+def main [
+  1:number <- copy 0
+  _ <- test1 1:number  # call with different ingredient and product
+]
+def test1 [
+  10:number <- next-ingredient
+  return 10:number/same-as-ingredient:0
+]
+$error: 0
+
+:(code)
+string to_string(const vector<double>& in) {
+  if (in.empty()) return "[]";
+  ostringstream out;
+  if (SIZE(in) == 1) {
+    out << no_scientific(in.at(0));
+    return out.str();
+  }
+  out << "[";
+  for (int i = 0; i < SIZE(in); ++i) {
+    if (i > 0) out << ", ";
+    out << no_scientific(in.at(i));
+  }
+  out << "]";
+  return out.str();
+}
+
+//: Conditional reply.
+
+:(scenario reply_if)
+def main [
+  1:number <- test1
+]
+def test1 [
+  return-if 0, 34
+  return 35
+]
++mem: storing 35 in location 1
+
+:(scenario reply_if_2)
+def main [
+  1:number <- test1
+]
+def test1 [
+  return-if 1, 34
+  return 35
+]
++mem: storing 34 in location 1
+
+:(before "End Rewrite Instruction(curr, recipe result)")
+// rewrite `reply-if a, b, c, ...` to
+//   ```
+//   jump-unless a, 1:offset
+//   reply b, c, ...
+//   ```
+if (curr.name == "reply-if" || curr.name == "return-if") {
+  if (curr.products.empty()) {
+    curr.operation = get(Recipe_ordinal, "jump-unless");
+    curr.name = "jump-unless";
+    vector<reagent> results;
+    copy(++curr.ingredients.begin(), curr.ingredients.end(), inserter(results, results.end()));
+    curr.ingredients.resize(1);
+    curr.ingredients.push_back(reagent("1:offset"));
+    result.steps.push_back(curr);
+    curr.clear();
+    curr.operation = get(Recipe_ordinal, "reply");
+    curr.name = "reply";
+    curr.ingredients.swap(results);
+  }
+  else {
+    raise << "'" << curr.name << "' never yields any products\n" << end();
+  }
+}
+// rewrite `reply-unless a, b, c, ...` to
+//   ```
+//   jump-if a, 1:offset
+//   reply b, c, ...
+//   ```
+if (curr.name == "reply-unless" || curr.name == "return-unless") {
+  if (curr.products.empty()) {
+    curr.operation = get(Recipe_ordinal, "jump-if");
+    curr.name = "jump-if";
+    vector<reagent> results;
+    copy(++curr.ingredients.begin(), curr.ingredients.end(), inserter(results, results.end()));
+    curr.ingredients.resize(1);
+    curr.ingredients.push_back(reagent("1:offset"));
+    result.steps.push_back(curr);
+    curr.clear();
+    curr.operation = get(Recipe_ordinal, "reply");
+    curr.name = "reply";
+    curr.ingredients.swap(results);
+  }
+  else {
+    raise << "'" << curr.name << "' never yields any products\n" << end();
+  }
+}