Filters Preference Page

Use the Command Link File Comparison Filters preference page to configure regular expressions-based filters that DeltaWalker will use when performing file comparison. Folder comparison based on file content - see the Command Link Folder Comparison preference page - will also use the filters you've setup here.

Filters enable ignoring text that is out of the scope of interest of the reviewer and thus increase the usefulness of the analysis performed and offered by DeltaWalker. They achieve this by narrowing the gap between the overly-technical representation of the text maintained by computers and the underlying meaning of the text expressed by humans.

A common real-world scenario in which filters are of great value is when text formatting is of no importance. Though guidelines, conventions, and standards used within a project or an organization are designed to keep such differences to a minimum, crossing the aforementioned boundaries is often a source of hindrances. Using filters, unimportant text formatting is easily taken out of the picture.

Software developers will find filters indispensable for keeping code comments out when comparing source files.

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File comparison filters image

Filters at a glance

DeltaWalker makes it easy to define a large set of filters and to use them as suitable for a specific comparison task. Filters are expressed through the de facto standard syntax of regular expressions and are given human-readable descriptions to lift off the burden of the mathematical notation and preserve the focus on the actual comparison review. Selective reuse of previously-defined filters is encouraged and aided by check boxes that control the inclusion or exclusion of specific filters during the actual comparison.

Filters offer a fine-grained control over what text to ignore during comparison—from entire lines of text to specific character sequences.

Filters by example

Blank lines vs. sequences of "blank" characters

Consider the following regular expression that matches lines either with no characters or containing only spaces and tab characters (often referred to as blanks):

^[ \t]*$

A filter configured to search with this pattern and to report same any lines where it finds matching parts will make the comparison ignore such lines. The result—differences comprised only of such matching lines will be discarded.

In contrast, a filter built on the same expression and defined to ignore the respective character sequences will keep a matching line and its meaning as a base for a difference but will let it correspond to another line, which may be non-blank in its raw form but which evaluates to a blank line after filtering.

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