comment repl cruft

prelude.ld

@@ -1111,7 +1111,8 @@ fn render_turtle! () -> {
 			add_call! ((:fill, r, g, b, a))
 			let #{heading
 				:pencolor (pen_r, pen_g, pen_b, pen_a)
-				:position (x, y) 
+				:position (x, y)
+				pendown?
 				...} = state
 			let first = mult ((0, 1), turtle_radius)
 			let (x1, y1) = first
@@ -1128,7 +1129,7 @@ fn render_turtle! () -> {
 			add_call! ((:endShape))
 			& there's a happy bug here: the stroke will be the same width as the pen width. Keep this for now. Consider also showing the pen colour here?
 			add_call! ((:stroke, pen_r, pen_g, pen_b, pen_a))
-			add_call! ((:line, 0, 0, x1, y1))
+			if pendown? then add_call! ((:line, 0, 0, x1, y1)) else nil
 			add_call! ((:pop))
 			:ok
 		}
@@ -1251,6 +1252,16 @@ fn setheading! {
 	(heading as :number) -> add_command! ((:setheading, heading))
 }
 
+fn showturtle! {
+	"If the turtle is hidden, shows the turtle. If the turtle is already visible, does nothing."
+	() -> add_command! ((:show))
+}
+
+fn hideturtle! {
+	"If the turtle is visible, hides it. If the turtle is already hidden, does nothing."
+	() -> add_command! ((:hide))
+}
+
 fn heading/vector {
 	"Takes a turtle heading, and returns a unit vector of that heading."
 	(heading) -> {
@@ -1287,6 +1298,8 @@ fn apply_command {
 		(:penwidth, pixels) -> assoc (state, :penwidth, pixels)
 		(:pencolor, color) -> assoc (state, :pencolor, color)
 		(:setheading, heading) -> assoc (state, :heading, heading)
+		(:show) -> assoc (state, :visible?, true)
+		(:hide) -> assoc (state, :visible?, false)
 	}
 }
 
@@ -1395,6 +1408,7 @@ pkg Prelude {
 	gte? & math
 	heading & turtles
 	heading/vector & math
+	hideturtle! & turtles
 	home! & turtles
 	inc & math
 	inv & math
@@ -1464,6 +1478,7 @@ pkg Prelude {
 	set? & sets
 	setheading! & turtles
 	show & strings
+	showturtle! & turtles
 	sin & math
 	slice & lists tuples strings
 	some & values

src/ludus.janet

@@ -52,7 +52,11 @@
 (comment
 # (do
 (def source `
-butlast ([1, 2, 3])
+hideturtle! ()
+showturtle! ()
+penup! ()
+pendown! ()
+pencolor! (colors :red)
 `)
 (def out (-> source 
  ludus