GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
GraphViz::Parse::Yacc(3) User Contributed Perl Documentation GraphViz::Parse::Yacc(3)

GraphViz::Parse::Yacc - Visualise grammars

  use GraphViz::Parse::Yacc;

  # Pass in a file generated via yacc -v
  my $graph = GraphViz::Parse::Yacc->new('Yacc.output');
  print $g->as_png;

This module makes it easy to visualise Parse::Yacc grammars. Writing Parse::Yacc grammars is tricky at the best of times, and grammars almost always evolve in ways unforseen at the start. This module aims to visualise a grammar as a graph in order to make the structure clear and aid in understanding the grammar.

Rules are represented as nodes, which have their name on the left of the node and their productions on the right of the node. The subrules present in the productions are represented by edges to the subrule nodes.

Thus, every node (rule) should be connected to the graph - otherwise a rule is not part of the grammar.

This uses the GraphViz module to draw the graph. Thanks to Damian Conway for the original idea.

This is the constructor. It takes one mandatory argument, which is a filename of the output file generated by running "yacc -v " on the grammar file. For example, if your Parse::Yacc grammar file is called "calc.yp", you would run "yacc -v calc.y" and pass in "calc.output" as an argument here. A GraphViz object is returned.

  # Pass in a file generated via yacc -v
  my $graph = GraphViz::Parse::Yacc->new('Yacc.output');
  print $g->as_png;

The grammar can be visualised in a number of different graphical formats. Methods include as_ps, as_hpgl, as_pcl, as_mif, as_pic, as_gd, as_gd2, as_gif, as_jpeg, as_png, as_wbmp, as_ismap, as_imap, as_vrml, as_vtx, as_mp, as_fig, as_svg. See the GraphViz documentation for more information. The two most common methods are:

  # Print out a PNG-format file
  print $g->as_png;

  # Print out a PostScript-format file
  print $g->as_ps;

Leon Brocard <acme@astray.com>

Copyright (C) 2001, Leon Brocard

This module is free software; you can redistribute it or modify it under the Perl License, a copy of which is available at <http://dev.perl.org/licenses/>.

2016-12-27 perl v5.32.1

Search for    or go to Top of page |  Section 3 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.