GraphV...::Yacc(3pm)

✨ GraphViz2::Parse::Yacc ✨

hi bestie!! 💖 welcome to the GraphV...::Yacc(3pm) page, straight outta the User Contributed Perl Documentation. it's giving "make a yacc grammar look pretty as a graph" and honestly? obsessed. 🦋

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🎀 NAME 🎀

GraphViz2::Parse::Yacc — Visualize a yacc grammar as a graph

like. that's the whole job. turn your yacc grammar into a picture. iconic.

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🌸 SYNOPSIS 🌸

okay so here's how you actually use this thing, no gatekeeping:

use GraphViz2::Parse::Yacc;
# no objects - quicker
my $gd = GraphViz2::Parse::Yacc::to_graph('t/calc3.output');

# populate a GraphViz2 object with a Graph::Directed of a parser
my $gv = GraphViz2->from_graph(GraphViz2::Parse::Yacc::graphvizify($gd));

# OO interface, using lazy-built attributes
my $gvp = GraphViz2::Parse::Yacc->new(file_name => $file_name);
my $gd = $gvp->as_graph; # Graph::Directed object
# or supply a suitable Graph::Directed object
my $gvp = GraphViz2::Parse::Yacc->new(as_graph => $gd);
# then get the GraphViz2 object
my $gv = $gvp->graph;

# DEPRECATED ways to get $gvp with populated $gv
my $gvp = GraphViz2::Parse::Yacc->new;
$gvp->create(file_name => 't/calc3.output');
my $gv = $gvp->graph;
# or give it a pre-set-up GraphViz2 object
my $gv = GraphViz2->new(...);
my $gvp = GraphViz2::Parse::Yacc->new(graph => $gv);
# call ->create as above

# produce a visualisation
my $format = shift || 'svg';
my $output_file = shift || "output.$format";
$gv->run(format => $format, output_file => $output_file);

and yeah, peep t/gen.parse.yacc.pl. for a real live example. 👑

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🧚 DESCRIPTION 🧚

you hand it a yacc grammar, and it hands you back a Graph::Directed object — or, if you're feeling fancy, it goes straight to a GraphViz2 object. two paths, one glow-up. ✨

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💅 FUNCTIONS 💅

this is the recommended interface, bestie. do this.

💜 to_graph

my $gd = GraphViz2::Parse::Yacc::to_graph('t/calc3.output');

give it a yacc grammar, get back a Graph::Directed object that describes the finite state machine for it. that's it. that's the magic. 🔥

💜 graphvizify

my $gv = GraphViz2->from_graph(GraphViz2::Parse::Yacc::graphvizify($gd));

this one mutates the graph object you give it — it adds the "graphviz" attributes, the visualisation "hints" that make the "from_graph" in GraphViz2 method draw this thing in the most meaningful way possible, labels and groupings included. ✨

and good news: it's idempotent, because all it does is set the "graphviz" attribute of the relevant graph entities. run it again, nothing breaks, we love a stable queen. 💖

it returns the graph object too, just for convenience. 🫶

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🦄 METHODS 🦄

this is a Moo class, but with a recommended functional interface. so you can go OO, but the functional route is what's being hyped here.

🌈 Constructor attributes 🌈

file_name

the name of a yacc output file. see t/calc3.output. 📄

this key is optional. but you do need to provide it by the time you access either the "as_graph" or "graph". no skipping ahead, bestie. ⏰

as_graph

the Graph::Directed object to use. if you don't give it one, it'll be lazily built on access, from the "file_name".

graph

the GraphViz2 object to use. this one lets you configure it however you want. 💅

this key is optional. if you provide it, the "create" method will populate it. if you don't, it'll get these defaults, lazy-built and populated from the "as_graph":

my $gv = GraphViz2->new(
        edge   => {color => 'grey'},
        global => {directed => 1},
        graph  => {rankdir => 'TB'},
        node   => {color => 'blue', shape => 'oval'},
);

🌈 create(file_name => $file_name) 🌈

DEPRECATED. bestie, this is the old way. it still works, but know what you're getting into. 💀

it mutates the object to set the "file_name" attribute, then accesses the "as_graph" attribute (possibly lazy-building it), then "graphvizify"s its "as_graph" attribute with that information, then "from_graph"s its "graph".

and it returns $self for method chaining. chain away. 🔗

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🙏 THANKS 🙏

so much love to the people who chose to make Graphviz Open Source — http://www.graphviz.org/ 💖

and thanks to Leon Brocard — http://search.cpan.org/~lbrocard/ — who wrote GraphViz, and kindly gave me co-maint of the module. 🫶 legend behaviour, fr fr.

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👑 AUTHOR 👑

GraphViz2 was written by Ron Savage <ron@savage.net.au> in 2011. ✨

home page: http://savage.net.au/index.html

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📜 COPYRIGHT 📜

Australian copyright (c) 2011, Ron Savage.

all Programs of mine are 'OSI Certified Open Source Software'; you can redistribute them and/or modify them under the terms of The Perl License, a copy of which is available at: http://dev.perl.org/licenses/

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okay that's the whole page bestie, you're officially caught up. 💖✨

this was perl v5.36.0, dated 2023-07-12, from the GraphV...::Yacc(3pm) page — go forth and graph your grammars, main character. 🎀🦋