tame/src/graph.xsl

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<?xml version="1.0"?>
<!--
Dependency graph
2018-02-01 13:11:51 -05:00
Copyright (C) 2016 R-T Specialty, LLC.
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" />
<import href="graph.xsl.apply" />
<!--
@node Dependency Graph
@appendix 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.}
-->
<!--
Create a graph from the given vertex set @var{$vertices}.
The resulting graph will be normalized with duplicate vertices and
edges removed,
making it suitable for ad hoc graph generation.@c
@footnote{This is done by calling @ttref{graph:union#1}.}
-->
<function name="graph:make-from-vertices"
as="element( preproc:sym-deps )">
<param name="vertices" as="element( preproc:sym-dep )*" />
<variable name="graph" as="element( preproc:sym-deps )">
<preproc:sym-deps>
<sequence select="$vertices" />
</preproc:sym-deps>
</variable>
<!-- dedupe/normalize -->
<sequence select="graph:union( $graph )" />
</function>
<!--
Produce a new graph that is the transpose of
@var{$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>
<!--
Merge sequence of graphs @var{$graphs} into a single graph by taking
the union of all vertices and edges.
Directionality will be preserved.
Edge attributes (@code{preproc:sym-ref/@@*)} will be set to the
union of all attributes on all edges of the same @code{@@name}.
@emph{If edge attributes do not share the same value,
the behavior is undefined.}
For example:
@float Figure, fig:union-graph
@verbatim
G₁: A->B->C
G₂: C->A
G₃: B->C->D
G: A->B->C->D
^____/
@end verbatim
@caption{(G₁ G₂ G₃)}
@end float
This function also removes duplicate vertices and edges,
so it can be used with a single (or multiple) graphs to normalize
and tidy things up.
Any unknown XML nodes are removed.
-->
<function name="graph:union" as="element( preproc:sym-deps )*">
<param name="graphs" as="element( preproc:sym-deps )*" />
<preproc:sym-deps>
<for-each-group select="$graphs/preproc:sym-dep"
group-by="@name">
<preproc:sym-dep name="{@name}">
<for-each-group select="current-group()/preproc:sym-ref"
group-by="@name">
<preproc:sym-ref>
<sequence select="current-group()/@*" />
<!-- keep our name (overrides the above) -->
<attribute name="name" select="@name" />
</preproc:sym-ref>
</for-each-group>
</preproc:sym-dep>
</for-each-group>
</preproc:sym-deps>
</function>
<!--
@menu
* Package Subgraphs:: Managing package dependencies
@end menu
-->
<!--
@node Package Subgraphs
@section Package Subgraphs
Each package has its own independent dependency graph.
These vertices may have @dfn{virtual edges} to other packages'
graphs@mdash{}edges that will be formed once combined the
referenced graph;
these edges are indicated with @code{preproc:sym-ref/@@src}.
Graph operations are usually performed on single packages,
but it is occionally necessary to traverse packages to recurisvely
resolve dependencies.
@ttref{graph:dep-lookup#3} makes this easy:
TODO: Generic graph functions.
-->
<!--
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.
Parameters are organized for partial application.
-->
<function name="graph:dep-lookup" as="element( preproc:sym-dep )?">
<param name="lookup" />
<param name="graph" as="element( preproc:sym-deps )" />
<param name="symbol" as="element( preproc:sym )" />
<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( $lookup,
f:apply( $lookup, $symbol ),
$symbol )
else
()" />
</function>
<!--
@ttref{graph:dep-lookup#3} can be used together with the convenience
function @ttref{graph:make-from-deps#2} to produce a graph that
contains all dependencies for a given symbol list.
Used together with @ttref{graph:reverse#1},
a reverse dependency graph can be easily created that provides a
useful ``used by'' relationship.
-->
<!--
Create a dependency graph containing all dependencies of the given
symbol list @var{$symbols}.
The graph contains the union of the minimal subset of all package
subgraphs@mdash{}only vertices representing a symbol in
@var{$symbols} or its direct dependencies are included.
This function is @emph{not} recursive;
it assumes that the given symbol list @var{$symbols} is sufficient
for whatever operation is being performed.
The lookup function @var{$lookup} is invoked once per symbol in
@var{$symbols} with the @code{preproc:sym} to look up.
The final result is used to produce a new normalized graph,
with any duplicate vertices and edges removed.
-->
<function name="graph:make-from-deps" as="element( preproc:sym-deps )*">
<param name="lookup" as="item()+" />
<param name="symbols" as="element( preproc:sym )*" />
<sequence select="graph:make-from-vertices(
for $symbol in $symbols
return f:apply( $lookup, $symbol ) )" />
</function>
<!--
@menu
* Graph Lookups:: Graph constructors using symbol lookups
@end menu
-->
<!--
@node Graph Lookups
@subsection Graph Lookups
-->
<!--
The provided graph lookups are constructors that use symbols to
locate a graph. Using partial application, they are convenient for
use in @ttref{graph:dep-lookup#3} to resolve external graphs.
-->
<!--
Look up a graph on a document indicated by a source symbol
@var{$symbol/@@src}.
The document will be loaded relative to @var{$rel-node} with the
file extension @var{$package-ext}.
There are no restrictions on the root node of the document,
but the @code{preproc:sym-deps} node is expected to be a child of
the root.
This function does not care if @var{$symbol} actually resolves to
anything in the destination package@mdash{
}such is up to the caller to decide.
If the referenced document contains no graph
(@code{preproc:sym-deps}), the empty sequence will be returned.
If the referenced document does not exist,
the result is implementation-defined.
Customarily, @var{$doc-ext} is ``xmlo'' (the compiled object file)
and @var{$rel-node} is the package from which @var{$symbol} was
obtained.
-->
<function name="graph:lookup-from-doc" as="element( preproc:sym-deps )?">
<param name="doc-ext" as="xs:string" />
<param name="rel-node" as="node()" />
<param name="symbol" as="element( preproc:sym )" />
<variable name="src" as="xs:string?"
select="$symbol/@src" />
<sequence select="if ( $src ) then
document( concat( $src, '.', $doc-ext ),
$rel-node )
/node()/preproc:sym-deps
else
()" />
</function>
</stylesheet>