The text in this section expects that you have read the chapter on what a regular expression is, or have previous knowledge on this subject.
All the editing tools are located in the tool bar above editing area. Each of them will be described in the following.
The selection tool is used to mark elements for cut-and-paste and drag-and-drop. This is very similar to a selection tool in any drawing program.
Using this tool you will insert normal text to match. The
text is matched literally, i.e. you do not have to worry about
escaping of special characters. In the example above the following
regular expression will be build: abc\*\\\)
Using this tool you insert
character ranges. Examples includes what in ASCII text says
[0-9]
, [^a-zA-Z,_]
. When
inserting an item with this tool a dialog will appear, in which
you specify the character ranges.
See description of repeated regular expressions.
This is the repeated elements. This includes what in ASCII syntax is represented using an asterix (*), a plus (+), a question mark (?), and ranges ({3,5}). When you insert an item using this tool, a dialog will appear asking for the number of times to repeat.
You specify what to repeat by drawing the repeated content inside the box which this tool inserts.
Repeated elements can both be built from the outside in and the inside out. That is you can first draw what to be repeated, select it and use the repeat tool to repeat it. Alternatively you can first insert the repeat element, and draw what is to be repeated inside it.
See description on the repeated regular expressions.
This is the alternative regular expression (|). You specify the alternatives by drawing each alternative on top of each other inside the box that this tool inserts.
See description on alternative regular expressions
The compound tool does not represent any regular expressions. It is used to group other sub parts together in a box, which easily can be collapsed to only its title. This can be seen in the right part of the screen dump above.
The line start and line end tools matches the start of the line, and the end of the line respectively. The regular expression in the screen dump above thus matches lines only matches spaces.
See description of position regular expressions.
The boundary tools matches a word boundary respectively a
non-word boundary. The regular expression in the screen dump thus
matches any words starting with the
. The word
the
itself is, however, not matched.
See description of boundary regular expressions.
The look ahead tools either specify a positive or negative regular expression to match. The match is, however, not part of the total match.
Note: You are only allowed to place lookaheads at the end of the regular expressions. The Regular Expression Editor widget does not enforce this.
See description of look ahead regular expressions.
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