1256 - scenarios now support keyboard

1 files changed, 55 insertions, 0 deletions

diff --git a/cpp/075scenario_keyboard.cc b/cpp/075scenario_keyboard.cc
new file mode 100644
index 00000000..d14e4de7
--- /dev/null
+++ b/cpp/075scenario_keyboard.cc
@@ -0,0 +1,55 @@
+//: Clean syntax to manipulate and check the keyboard in scenarios.
+//: Instruction 'assume-keyboard' implicitly creates a variable called
+//: 'keyboard' that is accessible inside other 'run' instructions in the
+//: scenario.
+
+:(scenarios run_mu_scenario)
+:(scenario keyboard_in_scenario)
+scenario keyboard-in-scenario [
+  assume-keyboard [abc]
+  run [
+    1:character, 2:boolean, keyboard:address <- read-key keyboard:address
+    3:character, 4:boolean, keyboard:address <- read-key keyboard:address
+    5:character, 6:boolean, keyboard:address <- read-key keyboard:address
+    7:character, 8:boolean, keyboard:address <- read-key keyboard:address
+  ]
+  memory-should-contain [
+    1 <- 97  # 'a'
+    2 <- 1  # first read-key call found a character
+    3 <- 98  # 'b'
+    4 <- 1  # second read-key call found a character
+    5 <- 99  # 'c'
+    6 <- 1  # third read-key call found a character
+    7 <- 0
+    8 <- 0  # fourth read-key call didn't find a character
+  ]
+]
+
+:(before "End Scenario Globals")
+const size_t KEYBOARD = Next_predefined_global_for_scenarios++;
+:(before "End Predefined Scenario Locals In Run")
+Name[tmp_recipe[0]]["keyboard"] = KEYBOARD;
+
+:(before "End Rewrite Instruction(curr)")
+// rewrite `assume-keyboard string` to
+//   ```
+//   keyboard:address <- new string  # hacky reuse of location
+//   keyboard:address <- init-fake-keyboard keyboard:address
+//   ```
+if (curr.name == "assume-keyboard") {
+  // insert first instruction
+  curr.operation = Recipe_number["new"];
+  assert(curr.products.empty());
+  curr.products.push_back(reagent("keyboard:address"));
+  curr.products[0].set_value(KEYBOARD);
+  Recipe[r].steps.push_back(curr);  // hacky that "Rewrite Instruction" is converting to multiple instructions
+  // leave second instruction in curr
+  curr.clear();
+  curr.operation = Recipe_number["init-fake-keyboard"];
+  assert(curr.ingredients.empty());
+  curr.ingredients.push_back(reagent("keyboard:address"));
+  curr.ingredients[0].set_value(KEYBOARD);
+  assert(curr.products.empty());
+  curr.products.push_back(reagent("keyboard:address"));
+  curr.products[0].set_value(KEYBOARD);
+}