1 files changed, 53 insertions, 0 deletions
diff --git a/cpp/074keyboard.mu b/cpp/074keyboard.mu
new file mode 100644
index 00000000..9cea3d1f
--- /dev/null
+++ b/cpp/074keyboard.mu
@@ -0,0 +1,53 @@
+# Wrappers around keyboard primitives that take a 'keyboard' object and are thus
+# easier to test.
+
+container keyboard [  # can't think of another word like screen/display, so real and fake keyboards use the same name
+  index:integer
+  data:address:array:character
+]
+
+recipe init-fake-keyboard [
+  default-space:address:array:location <- new location:type, 30:literal
+  result:address:keyboard <- new keyboard:type
+  buf:address:address:array:character <- get-address result:address:keyboard/deref data:offset
+#?   $start-tracing #? 1
+  buf:address:address:array:character/deref <- next-ingredient
+#?   $stop-tracing #? 1
+  idx:address:integer <- get-address result:address:keyboard/deref index:offset
+  idx:address:integer/deref <- copy 0:literal
+  reply result:address:keyboard
+]
+
+recipe read-key [
+  default-space:address:array:location <- new location:type, 30:literal
+  x:address:keyboard <- next-ingredient
+  {
+    break-unless x:address:keyboard
+    idx:address:integer <- get-address x:address:keyboard/deref, index:offset
+    buf:address:array:character <- get x:address:keyboard/deref, data:offset
+    max:integer <- length buf:address:array:character/deref
+    {
+      done?:boolean <- greater-or-equal idx:address:integer/deref, max:integer
+      break-unless done?:boolean
+      reply 0:literal, 0:literal/done, x:address:keyboard/same-as-ingredient:0
+    }
+    c:character <- index buf:address:array:character/deref, idx:address:integer/deref
+    idx:address:integer/deref <- add idx:address:integer/deref, 1:literal
+    reply c:character, 1:literal/found, x:address:keyboard/same-as-ingredient:0
+  }
+  c:character, found?:boolean <- read-key-from-keyboard
+  reply c:character, found?:boolean, x:address:keyboard/same-as-ingredient:0
+]
+
+recipe wait-for-key [
+  default-space:address:array:location <- new location:type, 30:literal
+  x:address:keyboard <- next-ingredient
+  {
+    break-unless x:address:keyboard
+    # on fake keyboards 'wait-for-key' behaves just like 'read-key'
+    c:character, x:address:keyboard <- read-key x:address:keyboard
+    reply c:character, x:address:keyboard/same-as-ingredient:0
+  }
+  c:character <- wait-for-key-from-keyboard
+  reply c:character, x:address:keyboard/same-as-ingredient:0
+]