Fix the bugs. Not all of them.

src/ludus/interpreter.cljc

@@ -876,8 +876,13 @@
 
 (defn get-line [source line]
   (if line
-    (let [lines (clojure.string/split source #"\n")]
+    (let [lines (clojure.string/split source #"\n")
-      (clojure.string/trim (nth lines (dec line))))))
+          numlines (count lines)
+          gettable? (> numlines line)]
+      (if gettable? 
+        (clojure.string/trim (nth lines (dec line)))
+        nil))
+    ))
 
 (def runtime-error
   #?(
@@ -895,7 +900,7 @@
         interpreted (interpret-ast parsed base-ctx)
         namespace (dissoc interpreted ::data/type ::data/name ::data/struct)
         context (ns->ctx namespace)]
-    (println "Prelude fully loaded.")
+    ; (println "Prelude fully loaded.")
     context))
 
 ; ;; TODO: update this to use new parser pipeline & new AST representation
@@ -948,7 +953,7 @@
         (println "On line" (get-in (ex-data e) [:ast :token :line]))
         (println ">>> " (get-line source (get-in (ex-data e) [:ast :token :line])))
         (println (ex-message e))
-        (pp/pprint (ex-data e))
+        ;(pp/pprint (ex-data e))
         (throw e)
         ))))
 

src/ludus/node.cljc

@@ -40,3 +40,14 @@
       		]
    	#?(:clj clj_result :cljs (clj->js clj_result))
    	))
+
+(do 
+ 	(def res (run "
+fd! (100)
+rt! (0.25)
+fd! (100)
+pencolor! (200)
+fd! (50)
+	"))
+ 	(:draw res)
+ 	)

src/ludus/postlude.ld

@@ -1,20 +1,22 @@
 & this file runs after any given interpretation
 & the goal is to output any global state
+& this does not have base loaded into it: must be pure ludus
 
 if turtle_state() :visible? then render_turtle! () else nil
 
-let console_msgs = deref (console)
+let console_msgs = flush! ()
-set! (console, [])
 
 let (r, g, b, a) = deref (bgcolor)
-set! (bgcolor, colors :black)
+make! (bgcolor, colors :black)
 
 let draw_calls = deref (p5_calls)
-set! (p5_calls, []) 
+make! (p5_calls, [])
 
 #{
 	& :result result is provided elsewhere
 	& :errors [] & if we get here there are no errors
 	:console console_msgs
-	:draw concat ([(:background, r, g, b, a)], draw_calls)
+	:draw concat (
+		[(:background, r, g, b, a), (:stroke, 255, 255, 255, 255)]
+		draw_calls)
 }

src/ludus/prelude.ld

@@ -127,6 +127,15 @@ fn append {
 
 ref console = []
 
+fn flush! {
+	"Clears the console, and returns the messages."
+	() -> {
+		let msgs = deref (console)
+		make! (console, [])
+		msgs 
+	}
+}
+
 fn add_msg! {
 	"Adds a message to the console."
 	(msgs) -> {
@@ -708,7 +717,9 @@ let turtle_angle = 0.375
 let turtle_color = (100, 100, 100, 100)
 
 fn render_turtle! () -> {
+	print! ("Rendering turtle")
 	let state = do turtle_states > deref > last
+	print! ("Collected state.")
 	if state :visible?
 		then {
 			add_call! ((:push))	
@@ -739,19 +750,19 @@ fn state/call () -> {
 	let states = deref (turtle_states)
 	let curr = last (states)
 	let prev = nth (states, sub (count (states), 2))
-	print! ("Curr, prev, command", curr, prev, cmd)
+	& print! ("Curr, prev, command", curr, prev, cmd)
 	match cmd with {
 		:forward -> if curr :pendown?
-			then make_line (curr :position, prev :position)
+			then make_line (prev :position, curr :position)
 			else nil
 		:back -> if curr :pendown?
-			then make_line (curr :position, prev :position)
+			then make_line (prev :position, curr :position)
 			else nil
 		:home -> if curr :pendown?
-			then make_line (curr :position, prev :position)
+			then make_line (prev :position, curr :position)
 			else nil
 		:goto -> if curr :pendown?
-			then make_line (curr :position, prev :position)
+			then make_line (prev :position, curr :position)
 			else nil
 		:penwidth -> (:strokeWeight, curr :penwidth)
 		:pencolor -> {
@@ -859,6 +870,8 @@ fn apply_command {
 	"Takes a turtle state and a command and calculates a new state."
 	(state, command) -> match command with {
 		(:goto, (x, y)) -> assoc (state, :position, (x, y))
+		(:home) -> assoc (state, :position, (0, 0))
+		(:clear) -> assoc (state, :position, (0, 0))
 		(:right, turns) -> update (state, :heading, sub (_, turns))
 		(:left, turns) -> update (state, :heading, add (_, turns))
 		(:forward, steps) -> {
@@ -928,6 +941,7 @@ ns prelude {
 	inc
 	dec
 	print!
+	flush!
 	console
 	show
 	prn!
@@ -995,6 +1009,7 @@ ns prelude {
 	ceil
 	round
 	range
+	colors
 	forward!, fd!
 	back!, bk!
 	right!, rt!
@@ -1008,6 +1023,6 @@ ns prelude {
 	pencolor, penwidth
 	heading/vector
 	turtle_state
-	p5_calls, turtle_states, turtle_commands
+	p5_calls, turtle_states, turtle_commands, bgcolor
 	render_turtle!
 }