diagrams-svg is a an SVG backend for diagrams. Diagrams is a powerful, flexible, declarative domain-specific language for creating vector graphics, using the Haskell programming language.

diagrams-svg is a work in progress, and some features are not implemented yet. However, it is functional enough that hs-logo uses it. Check out the issues page to get an idea of the features that are missing.

Installation

cabal update && cabal install diagrams-svg

Usage

A simple example that uses diagrams-svg to draw a square.

import Diagrams.Prelude
import Diagrams.Backend.SVG.CmdLine

b1 = square 20 # lw 0.002

main = defaultMain (pad 1.1 b1)

Save this to file named Square.hs and compile this program:

ghc --make Square.hs

This will generate an executable which, when run produces an SVG file. Run the executable with the --help option to find out more about how to call it.

$ ./Square --help
Command-line diagram generation.

Square [OPTIONS]

Common flags:
  -w --width=INT    Desired width of the output image
  -h --height=INT   Desired height of the output image
  -o --output=FILE  Output file
  -? --help         Display help message
  -V --version      Print version information

You must pass an output file name with a .svg extension to generate the SVG file.

$ ./Square -o square.svg

The command above generates the SVG file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
    "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="22.0" height="22.0" viewBox="0 0 22 22">
  <g>
    <g stroke="rgb(0,0,0)" stroke-opacity="1.0" fill="rgb(0,0,0)" fill-opacity="0.0" stroke-width="2.0e-3">
       <path d="M 21.0,21.0 l -2.220446049250313e-15,-20.0 h -20.0 l -2.220446049250313e-15,20.0 Z" />
    </g>
  </g>
</svg>

Other Backends for Diagrams

• diagrams-cairo
• diagrams-postscript
• diagrams-canvas