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Frontmatter

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Author 1
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@bind angle HTML("<input type='range' min='0' step='$(pi/100)' max='$(pi/2)'>")
236 ms
Error message

MethodError: no method matching right!(::Main.workspace#2.Turtle, ::Missing)

Closest candidates are:

right!(::Main.workspace#2.Turtle, ::Number) at ~/work/disorganised-mess/disorganised-mess/turtles.jl#==#fc44503a-b0bf-11ea-0f28-510784847241:1

Stack trace

Here is what happened, the most recent locations are first:

  1. (::var"#7#8"{typeof(Main.workspace#2.right!), typeof(Main.workspace#2.forward!), Missing, Colon})(t::Main.workspace#2.Turtle)
    from This cell: line 4
    	for i in 1:100		right!(t, angle)		forward!(t, i)
  2. Show more...
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turtle_drawing() do t
for i in 1:100
right!(t, angle)
forward!(t, i)
end
end
---

🐢 definition

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161 μs
mutable struct Turtle
pos::Tuple{Number, Number}
heading::Number
pen_down::Bool
history::Drawing
end
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1.4 ms
Vector{String} (alias for Array{String, 1})
Drawing = Vector{String}
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15.3 μs

Turtle commands

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178 μs
forward! (generic function with 1 method)
function forward!(🐢::Turtle, distance::Number)
old_pos = 🐢.pos
new_pos = 🐢.pos = old_pos .+ (distance .* (cos(🐢.heading), sin(🐢.heading)))
if 🐢.pen_down
push!(🐢.history, """<line x1="$(old_pos[1])" y1="$(old_pos[2])" x2="$(new_pos[1])" y2="$(new_pos[2])" stroke="black" stroke-width="3" />""")
end
🐢
end
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996 μs
backward! (generic function with 1 method)
backward!(🐢::Turtle, by::Number) = foward!(🐢, -by)
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405 μs
right! (generic function with 1 method)
function right!(🐢::Turtle, angle::Number)
🐢.heading -= angle
end
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495 μs
left! (generic function with 1 method)
left!(🐢::Turtle, angle::Number) = right!(🐢, -angle)
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409 μs

Function to make turtle drawings with

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163 μs
turtle_drawing (generic function with 1 method)
function turtle_drawing(f::Function)
🐢 = Turtle((150, 150), pi*3/2, true, String[])
f(🐢)
image = """<svg version="1.1"
baseProfile="full"
width="300" height="300"
xmlns="http://www.w3.org/2000/svg">""" * join(🐢.history) * "</svg>"
return HTML(image)
end
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675 μs