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The diagrams library provides an embedded domain-specific language (EDSL) for creating simple pictures and diagrams in Haskell


Core DSL


Do we either want

yellowCircle x y radius = yellowFill $ circleShape x y radius


drawYellowCircle x y radius = do $

   setFill yellow
   drawCircle x y radius


The first version allows better reuse and functional composition.


  • graphical primitives
    • path
      • boundingBox
      • moveTo, lineTo, cubic bezier, quadratic bezier, arcTo
    • text
      • boundingBox
      • convertToPath
    • circle
      • boundingBox
      • convertToPath
    • ellipse
      • boundingBox
      • convertToPath
    • rectangle
      • boundingBox
      • convertToPath
    • polygon
      • boundingBox
      • convertToPath
    • polyline
      • boundingBox
      • convertToPath
  • graphical attributes
    • fill
      • paint
        • solid color, gradient, pattern
      • fill rule
        • evenOdd, nonZero
    • stroke
      • paint
        • solid color, gradient, pattern
      • width
      • line cap
      • line join
      • miter limit
      • dash
        • offset
        • array
    • marker symbols
    • effects
      • shadow, blur, turbulence
  • constraint solving
  • animations/pages/frames



  • inset, outset
  • boolean operations
  • morphing
  • approximation (autotrace)


Shapes and symbols


Many Haskell graphic libraries are tied to a specific rendering backend (Cairo, OpenGL, libGD etc) which makes collaboration and reuse of code and data structures very hard or impossible.

Also some dependencies are hard to fulfill. Cairo is very difficult to install on Mac OS 10.6. If you just need to generate PDF diagrams, you could choose the pure HPDF library where e.g. Hieroglyph can not be installed because of its Cairo dependence.


  • interactive drawing via Cairo
  • PDF export via pure HPDF
  • EPS export
  • SWF export
  • LaTeX export
  • exotic backends


  • pure Haskell PNG import via pngload
  • pure Haskell SVG import


Related non-Haskell projects

Food for thought