tame/src/graph.xsl

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<?xml version="1.0"?>
<!--
Dependency graph
Copyright (C) 2016 LoVullo Associates, Inc.
This file is part of TAME.
TAME is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see
<http://www.gnu.org/licenses/>.
-->
<stylesheet version="2.0"
xmlns="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:f="http://mikegerwitz.com/hoxsl/apply"
xmlns:graph="http://www.lovullo.com/tame/graph"
xmlns:preproc="http://www.lovullo.com/rater/preproc">
<import href="../hoxsl/src/apply.xsl" />
<!--
@node Dependency Graph
@section Dependency Graph
The dependency graph is a directed graph consisting of
every known symbol,
post-expansion (@pxref{Macro Expansion}).
Cycles are produced only by function recursion and otherwise cause an
error, so the graph is studied as a DAG (directed acyclic graph)
with few exceptions.
Vertices in the dependency graph are represented by
@code{preproc:sym-dep} nodes,
and edges by child @code{preproc:sym-ref} nodes.
Graphs are represented by @code{preproc:sym-deps}.
The graph of each package is considered to be a subgraph of the
entire dependency graph for a particular system.@c
@footnote{The node names are for compatibility with legacy systems
and may change in the future; always use the graph API, and only
use the node QNames for type checks.}
-->
<!--
Retrieve dependenices for @var{$symbol} on the @var{$graph},
using the lookup function @var{$lookup} to resolve external
subgraphs.
@var{$lookup} will be used only if the symbol cannot be
found in @var{$graph},
in which case the result of @var{$lookup} will used used in a
recursive call as the new @var{$graph}.
From a graph perspective,
the dependencies are edges on the @var{$symbol} vertex.
-->
<function name="graph:dep-lookup" as="element( preproc:sym-dep )?">
<param name="symbol" as="element( preproc:sym )" />
<param name="graph" as="element( preproc:sym-deps )" />
<param name="lookup" />
<variable name="deps" as="element( preproc:sym-dep )?"
select="$graph/preproc:sym-dep
[ @name = $symbol/@name ]" />
<sequence select="if ( exists( $deps ) ) then
$deps
else if ( $lookup ) then
graph:dep-lookup( $symbol,
f:apply( $lookup, $symbol ),
$lookup )
else
()" />
</function>
<!--
Produce a new graph that is the transpose of
@var{$graph}@mdash{}that is,
the graph @var{$graph} with the direction of all of its edges
reversed.
This is useful for processing what symbols are @emph{used by} other
symbols.
For example:
@float Figure, fig:reverse-graph
@verbatim
G: A->B->C->E
\
`->D
G': A<-B<-C<-E
^
`D
@end verbatim
@caption{G' is the transpose of G}
@end float
Edge attributes (@code{preproc:sym-ref/@@*)} will be set to the
union of all attributes on all edges of the same @code{@@name} in
@code{$graph}.
@emph{If edge attributes do not share the same value,
the behavior is undefined.}
-->
<function name="graph:reverse" as="element( preproc:sym-deps )">
<param name="graph" as="element( preproc:sym-deps )" />
<variable name="reversed" as="element( preproc:sym-dep )*">
<for-each-group select="$graph//preproc:sym-ref"
group-by="@name">
<preproc:sym-dep name="{@name}">
<for-each select="current-group()/ancestor::preproc:sym-dep">
<preproc:sym-ref>
<sequence select="current-group()/@*" />
<!-- keep our name (overrides the above) -->
<attribute name="name" select="@name" />
</preproc:sym-ref>
</for-each>
</preproc:sym-dep>
</for-each-group>
</variable>
<preproc:sym-deps>
<!-- vertices in $graph with no dependencies will not be in
$reversed -->
<for-each select="$graph/preproc:sym-dep[ not(
@name = $reversed/preproc:sym-ref/@name ) ]">
<preproc:sym-dep name="{@name}" />
</for-each>
<sequence select="$reversed" />
</preproc:sym-deps>
</function>
</stylesheet>