turtle

turtle

a gisp REPL with turtle abilities

This is an example of adding new built-in methods to gisp, based on https://github.com/GaryBrownEEngr/turtle (and Ebitengine,

Additional built-ins

(color r g b [a])                             ; return a color
(turtle [ (width height show) ] drawFunction) ; create a turtle window and run `drawFunction`
(clear t [ color ])                           ; clear window (and, if present, fill with color `color`
(show [bool|'turtle|'arrow|'imagefile)        ; show/hide cursor and set shape (turtle, arrow or from image file)
(speed t pixelsPerSecond)                     ; set speed of drawing
(scale t number)                              ; scale cursor
(pencolor t color)                            ; set pen color
(pendown t)                                   ; pen down (draw line when moving)
(pendown t)                                   ; pen up (move without drawing)
(fill t color)                                ; fill drawing with color
(size t n)                                    ; line width (`n` pixels)
(dot t n)                                     ; draw a dot of radius `n`
(angle t angle)                               ; rotate to angle
(left t angle)                                ; rotate left of `angle` degrees
(right t angle)                               ; rotate right of `angle` degrees
(panleft t distance)
(panright t distance)
(forward t distance)                          ; move forward of `distance` pixels
(backward t distance)                         ; move backward of `distance` pixels
(goto t x y)                                  ; go to `x, y` coordinates
(pos t)                                       ; return current position (x, y)
(pointto t x y)                               ; point to `x, y` coordinates
(circle t radius angle steps)                 ; draw a circle of radious `radius` 

See the file turtle.gisp for a working example

> go run . turtle.gisp