Hello, I’m relatively new to Haskell. I’m wondering if it exist a tool to graphically represent Haskell code. Look at the little graphics at: http://www.haskell.org/arrows/index.html (and following pages) from Ross Paterson. http://www.haskell.org/arrows/index.htm If found these very useful to understand the Arrow monad. Why not automatise this in a tool? Such a tool could draw a graphic from the code of a program. This could be done entirely automatically from the types of the functions. Let’s try to do it on a simple example, as an exercise: f = Map (+1) How does this function could be represented? It contains the (+) function. This function has the type (+) :: Num a => a -> a -> a.
From this type we could deduce the graphic:
[image: Haskell schematic_html_m20060f13.gif] Or a curried version: [image: Haskell schematic_html_5155f0eb.gif] The function (+1) then is: [image: Haskell schematic_html_m68795eb7.gif] The function map could be drawn like this : [image: Haskell schematic_html_m28c92a58.gif] Or like this: [image: Haskell schematic_html_m6ae433ea.gif] And the entire function map (+1) could be represented as: [image: Haskell schematic_html_macb1643.gif] Thanks to the advanced type system of Haskell, everything could be deduced from the type signatures. Such a tool would be recreational and educational. One could zoom in and out in a program, to display more or less details. This could help understand a program, globally or locally. We could even imagine a constructive version of the tool, where the programmer would draw functions from a toolbox, and stick them into the graphic! Does a tool approaching this already exist? If not, would it be a good project? Cheers, Corentin
