Undo wrong fix for exec_if; fix peek-stack for false on boolean stack

src/propeller/push/instructions/code.cljc

@@ -124,7 +124,7 @@
   :exec_if
   ^{:stacks #{:boolean :exec}}
   (fn [state]
-    (make-instruction state #(if %1 %2 %3) [:boolean :exec :exec] :exec)))
+    (make-instruction state #(if %1 %3 %2) [:boolean :exec :exec] :exec)))
 
 ;; If the top BOOLEAN is TRUE, leaves the first item on the EXEC stack to be
 ;; executed. Otherwise, it removes it. Acts as a NOOP unless there is at least

src/propeller/push/state.cljc

@@ -35,12 +35,19 @@
   [state stack]
   (empty? (get state stack)))
 
+;;; Returns the top item on the stack
+;(defn peek-stack
+;  [state stack]
+;  (if-let [top-item (first (get state stack))]
+;    top-item
+;    :no-stack-item))
+
 ;; Returns the top item on the stack
 (defn peek-stack
   [state stack]
-  (if-let [top-item (first (get state stack))]
+  (if (empty? (get state stack))
-    top-item
+    :no-stack-item
-    :no-stack-item))
+    (first (get state stack))))
 
 ;; Returns the top n items on the stack, as a chunk. If there are less than n
 ;; items on the stack, returns the entire stack

src/propeller/push/utils/helpers.cljc

@@ -32,6 +32,7 @@
 (defn make-instruction
   [state function arg-stacks return-stack]
   (let [popped-args (get-args-from-stacks state arg-stacks)]
+    (println popped-args)
     (if (= popped-args :not-enough-args)
       state
       (let [result (apply function (:args popped-args))

src/propeller/session.cljc

@@ -13,21 +13,21 @@
     '(1 2 :integer_add) state/empty-state 1000)
 
 (interpreter/interpret-program
-    '(3 5 :integer_eq :exec_if (1 "yes") (2 "no"))
+    '(3 3 :integer_eq :exec_if (1 "yes") (2 "no"))
     state/empty-state
     1000)
 
-#_(interpreter/interpret-program
+(interpreter/interpret-program
-    '(in1 :string_reverse 1 :string_take "?" :string_eq :exec_if
+    '(:in1 :string_reverse 1 :string_take "?" :string_eq :exec_if
-          (in1 " I am asking." :string_concat)
+          (:in1 " I am asking." :string_concat)
-          (in1 " I am saying." :string_concat))
+          (:in1 " I am saying." :string_concat))
     (assoc state/empty-state :input {:in1 "Can you hear me?"})
     1000)
 
-#_(interpreter/interpret-program
+(interpreter/interpret-program
-    '(in1 :string_reverse 1 :string_take "?" :string_eq :exec_if
+    '(:in1 :string_reverse 1 :string_take "?" :string_eq :exec_if
-          (in1 " I am asking." :string_concat)
+          (:in1 " I am asking." :string_concat)
-          (in1 " I am saying." :string_concat))
+          (:in1 " I am saying." :string_concat))
     (assoc state/empty-state :input {:in1 "I can hear you."})
     1000)
 
@@ -61,7 +61,7 @@
           :step-limit              100
           :parent-selection        :lexicase})
 
-(gp/gp {:instructions            propeller.problems.software.number-io/instructions
+#_(gp/gp {:instructions            propeller.problems.software.number-io/instructions
         :error-function          propeller.problems.software.number-io/error-function
         :max-generations         500
         :population-size         500