STAG-DIFF(1) User Contributed Perl Documentation STAG-DIFF(1)NAME
stag-diff - finds the difference between two stag files
SYNOPSIS
stag-diff -ignore foo-id -ignore bar-id file1.xml file2.xml
DESCRIPTION
Compares two data trees and reports whether they match. If they do not
match, the mismatch is reported.
-help|h
shows this document
-ignore|i ELEMENT
these nodes are ignored for the purposes of comparison. Note that
attributes are treated as elements, prefixed by the containing
element id. For example, if you have
<foo ID="wibble">
And you wish to ignore the ID attribute, then you would use the
switch
-ignore foo-ID
You can specify multiple elements to ignore like this
-i foo -i bar -i baz
You can also specify paths
-i foo/bar/bar-id
-parser|p FORMAT
which parser to use. The default is XML. This can also be
autodetected by the file suffix. Other alternatives are sxpr and
itext. See Data::Stag for details.
-report|r ELEMENT
report mismatches as they occur on each element of type ELEMENT
multiple elements can be specified
-verbose|v
used in conjunction with the -report switch
shows the tree of the mismatching element
OUTPUT
If a mismatch is reported, a report is generated displaying the subpart
of the tree that could not be matched. This will look like this:
REASON: no_matching_node: annotation
no_matching_node: feature_set
no_matching_node: feature_span
no_matching_node: evidence
no_matching_node: evidence-id
data_mismatch(:15077290 ne :15077291): evidence-id AND
evidence-id
Due to the nature of tree matching, it can be difficult to specify
exactly how trees do not match. To investigate this, you may need to
use the -r and -v options. For the above output, I would recommend
using
stag-diff -r feature_span -v
ALGORITHM
Both trees are recursively traversed... see the actual code for how
this works
The order of elements is not important; eg
<foo>
<bar>
<baz>1</baz>
</bar>
<bar>
<baz>2</baz>
</bar>
</foo>
matches
<foo>
<bar>
<baz>2</baz>
</bar>
<bar>
<baz>1</baz>
</bar>
</foo>
The recursive nature of this algorithm means that certain tree
comparisons will explode wrt time and memory. I think this will only
happen with very deep trees where nodes high up in the tree can only be
differentiated by nodes low down in the tree.
Both trees are loaded into memory to begin with, so it may thrash with
very large documents
AUTHOR
Chris Mungall cjm at fruitfly dot org
SEE ALSO
Data::Stag
POD ERRORS
Hey! The above document had some coding errors, which are explained
below:
Around line 189:
=over should be: '=over' or '=over positive_number'
perl v5.20.2 2009-12-14 STAG-DIFF(1)