1GraphViz2::Parse::STT(3U)ser Contributed Perl DocumentatiGornaphViz2::Parse::STT(3)
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NAME

6       GraphViz2::Parse::STT - Visualize a Set::FA::Element state transition
7       table as a graph
8

SYNOPSIS

10           use GraphViz2::Parse::STT;
11           use File::Slurp; # For read_file().
12           my $stt = read_file('sample.stt.1.dat');
13           # no objects - quicker
14           my $gd = GraphViz2::Parse::STT::to_graph($stt);
15
16           # populate a GraphViz2 object with a Graph::Directed of a parser
17           my $gv = GraphViz2->from_graph(GraphViz2::Parse::STT::graphvizify($gd));
18
19           # visualise with another mode
20           $gd = GraphViz2::Parse::STT::graphvizify($gd, 're_nodes'); # or 're_edges'
21
22           # OO interface, using lazy-built attributes
23           my $gvp = GraphViz2::Parse::STT->new(stt => $stt, mode => 're_structs');
24           my $gd = $gvp->as_graph; # Graph::Directed object
25           # or supply a suitable Graph::Directed object
26           my $gvp = GraphViz2::Parse::STT->new(as_graph => $gd);
27           # then get the GraphViz2 object
28           my $gv = $gvp->graph;
29
30           # DEPRECATED ways to get $gvp with populated $gv
31           my $gvp = GraphViz2::Parse::STT->new;
32           $gvp->create(stt => $stt);
33           my $gv = $gvp->graph;
34           # or give it a pre-set-up GraphViz2 object
35           my $gv = GraphViz2->new(...);
36           my $gvp = GraphViz2::Parse::STT->new(graph => $gv);
37           # call ->create as above
38
39           # produce a visualisation
40           my $format = shift || 'svg';
41           my $output_file = shift || "output.$format";
42           $gv->run(format => $format, output_file => $output_file);
43
44       See t/gen.parse.stt.t.
45
46       Note: t/sample.stt.2.dat is output from Graph::Easy::Marpa::DFA V 0.70,
47       and can be used instead of t/sample.stt.1.dat in the above code.
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DESCRIPTION

50       Takes a Set::FA::Element-style state transition table and converts it
51       into a Graph::Directed object, or directly into a GraphViz2 object.
52

FUNCTIONS

54       This is the recommended interface.
55
56   to_graph
57           my $gd = GraphViz2::Parse::STT::to_graph($stt);
58
59       Given STT text, returns a Graph::Directed object describing the finite
60       state machine for it.
61
62       The nodes are all states, and the edges are regular expressions that
63       cause a transition to another state.
64
65   graphvizify
66           my $gv = GraphViz2->from_graph(GraphViz2::Parse::STT::graphvizify($gd, $mode));
67
68       Mutates the given graph object to add to it the "graphviz" attributes
69       visualisation "hints" that will make the "from_graph" in GraphViz2
70       method visualise this regular expression in the most meaningful way,
71       including labels and groupings.
72
73       It is idempotent, but in "re_nodes" mode, it deletes the transition
74       edges and replaces them with additional nodes and edges.
75
76       If a second argument is given, it will be the visualisation "mode". The
77       default is "re_structs". Also available is "re_nodes", and "re_edges"
78       where the regular expressions are simply added as labels to the state-
79       transition edges.
80
81       Returns the graph object for convenience.
82

METHODS

84       This is a Moo class, but with a recommended functional interface.
85
86   Constructor attributes
87       stt
88
89       Text with a state transition table, with a Perl-ish list of arrayrefs,
90       each with 3 elements.
91
92       That is, it is the contents of the arrayref 'transitions', which is one
93       of the keys in the parameter list to Set::FA::Element's new().
94
95       A quick summary of each element of this list, where each element is an
96       arrayref with 3 elements:
97
98       o [0] A state name
99       o [1] A regexp
100       o [2] Another state name (which may be the same as the first)
101
102       The DFA in Set::FA::Element tests the 'current' state against the state
103       name ([0]), and for each state name which matches, tests the regexp
104       ([1]) against the next character in the input stream. The first regexp
105       to match causes the DFA to transition to the state named in the 3rd
106       element of the arrayref ([2]).
107
108       See t/sample.stt.1.dat for an example.
109
110       This key is optional. You need to provide it by the time you access
111       either the "as_graph" or "graph".
112
113       as_graph
114
115       The Graph::Directed object to use. If not given, will be lazily built
116       on access, from the "stt".
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118       graph
119
120       The GraphViz2 object to use. This allows you to configure it as
121       desired.
122
123       This key is optional. If provided, the "create" method will populate
124       it.  If not, it will have these defaults, lazy-built and populated from
125       the "as_graph".
126
127           my $gv = GraphViz2->new(
128                   edge   => {color => 'grey'},
129                   global => {directed => 1},
130                   graph  => {rankdir => 'TB'},
131                   node   => {color => 'blue', shape => 'oval'},
132           );
133
134       mode
135
136       The mode to be used by "graphvizify".
137
138   create(regexp => $regexp, mode => $mode)
139       DEPRECATED. Mutates the object to set the "stt" attribute, then
140       accesses the "as_graph" attribute (possibly lazy-building it), then
141       "graphvizify"s its "as_graph" attribute with that information, then
142       "from_graph"s its "graph".
143
144       Returns $self for method chaining.
145

THANKS

147       Many thanks are due to the people who chose to make Graphviz
148       <http://www.graphviz.org/> Open Source.
149
150       And thanks to Leon Brocard <http://search.cpan.org/~lbrocard/>, who
151       wrote GraphViz, and kindly gave me co-maint of the module.
152

AUTHOR

154       GraphViz2 was written by Ron Savage <ron@savage.net.au> in 2011.
155
156       Home page: <http://savage.net.au/index.html>.
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159       Australian copyright (c) 2011, Ron Savage.
160
161       All Programs of mine are 'OSI Certified Open Source Software'; you can
162       redistribute them and/or modify them under the terms of The Perl
163       License, a copy of which is available at: http://dev.perl.org/licenses/
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167perl v5.32.1                      2021-01-27          GraphViz2::Parse::STT(3)
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