1921 - show trace by clicking on code

Region to click on to edit is now reduced to just the menu bar for the
sandbox (excluding the 'x' for deleting the sandbox). The symmetry there
might be useful, but we'll see if the relative click area is
in line with how commonly the actions are performed.

1 files changed, 15 insertions, 8 deletions

diff --git a/029tools.cc b/029tools.cc
index cd4123fa..587818ea 100644
--- a/029tools.cc
+++ b/029tools.cc
@@ -12,15 +12,22 @@ TRACE,
 Recipe_ordinal["trace"] = TRACE;
 :(before "End Primitive Recipe Implementations")
 case TRACE: {
-  if (SIZE(ingredients) != 2) {
-    raise << current_recipe_name() << ": 'trace' takes exactly two ingredients rather than '" << current_instruction().to_string() << "'\n" << end();
-    break;
+  if (SIZE(ingredients) == 2) {
+    assert(is_literal(current_instruction().ingredients.at(0)));
+    string label = current_instruction().ingredients.at(0).name;
+    assert(is_literal(current_instruction().ingredients.at(1)));
+    string message = current_instruction().ingredients.at(1).name;
+    trace(1, label) << message << end();
+  }
+  else if (SIZE(ingredients) == 1) {
+    assert(is_literal(current_instruction().ingredients.at(0)));
+    string message = current_instruction().ingredients.at(0).name;
+    cerr << "tracing " << message << '\n';
+    trace(1, "app") << message << end();
+  }
+  else {
+    raise << current_recipe_name() << ": 'trace' takes one or two ingredients rather than '" << current_instruction().to_string() << "'\n" << end();
   }
-  assert(is_literal(current_instruction().ingredients.at(0)));
-  string label = current_instruction().ingredients.at(0).name;
-  assert(is_literal(current_instruction().ingredients.at(1)));
-  string message = current_instruction().ingredients.at(1).name;
-  trace(1, label) << message << end();
   break;
 }