Pattern Language Reference

This appendix presents an alphabetical list of operators in the TC pattern language.

And

expr1 and expr2

Matches regions that match both expressions.

Anywhere After

anywhere after expr

Matches regions anywhere after some match to expr.

Anywhere Before

anywhere before expr

Matches regions anywhere before some match to expr.

Balanced from-to

balanced from expr1 to expr2

Matches a nested set of regions whose start delimiters match expr1 and end delimiters match expr2.

Case Sensitive

case sensitive expr

Forces literal and regular expression matches inside expr to be case-sensitive.

not case sensitive expr

Forces literal and regular expression matches inside expr to be case-insensitive (the default).

Contains

contains expr

Matches regions that contain at least one match to expr.

Either-Or

either expr1 or expr2

Matches regions that match either expr1 or expr2. The either is optional.

End of

end of expr

Matches the end points of regions matching expr. Always returns a set of zero-length regions.

Ends

ends expr

Matches regions that end at the same point as expr. Ignores background regions around the end point.

Equals

equals expr

Matches regions that match expr. Synonyms include = and equal to. Ignores background regions around both start point and end point.

Flatten

flatten expr

Flattens the regions that match expr, by combining nested and overlapping regions into a single region.

From-To

from expr1 to expr2

Matches a flat region set consisting of regions that start with a match to expr1 and end with the next match to expr2.

Identifier

identifier

Matches the regions matched by the pattern bound to identifier in the pattern library.

Ignoring

expr1 ignoring expr2

Sets the background set to the regions matching expr2, then evaluates expr1 and returns its matches.

In

in expr

Matches regions lie in some match to expr.

Is

identifier is expr

Assigns the pattern expr to identifier in the pattern library, and returns the matches to expr.

Just After

just after expr

Matches regions that lie after and adjacent to some match to expr. Ignores background regions when testing for adjacency.

Just Before

just before expr

Matches regions that lie before and adjacent to some match to expr. Ignores background regions when testing for adjacency.

Literal

"string"

'string'

Matches regions consisting of the literal characters string. Either single or double quotes may be used to delimit the string.

Melt

melt expr

Melts the regions that match expr by combining nested, overlapping, or adjacent regions into a single region.

Nonzero

nonzero expr

Matches regions that match expr and contain at least one character.

Not

expr1 not expr2

Matches regions matching expr1 that do not match expr2.

Nth

nth expr

nth expr1 in expr2

nth expr1 before expr2

nth expr1 after expr2

The first form matches the nth region in the document that matches expr. The other forms match the nth match to expr1 that lies in, before, or after each match to expr2.

The ``nth'' part can be written in a variety of ways:

1st, 2nd, 3rd, 4th, ...
first, second, third, ..., tenth
last, 2nd from last, 3rd from last, ...
second from last, third from last, ...

Or

expr1 or expr2

Matches regions that match either expr1 or expr2.

Overlaps

overlaps expr

Matches regions that overlap some region matching expr.

Overlaps End Of

overlaps end of expr

Matches regions that overlap the end point of some region matching expr.

Overlaps Start Of

overlaps start of expr

Matches regions that overlap the start point of some region matching expr.

Prefix

prefix identifier expr

Changes the current namespace to identifier for the scope of expr.

Regular Expression

/regexp/

Matches regions that match the regular expression regexp.

Start of

start of expr

Matches the start points of regions matching expr.

Starts

starts expr

Matches regions that start at the same point as expr. Ignores background regions around the start point.

Then

expr1 then expr2

Matches regions that are the concatenation of a region matching expr1 with a region matching expr2 that lies after and adjacent to it. Ignores background regions when determining whether expr1 and expr2 are adjacent.

Trim

expr1 trim expr2

Matches regions that match expr1 with an overlapping match to expr2 removed from the start or end point.

View

view source expr

view rendered expr

Forces literals and regular expressions inside expr to be matched against the HTML source or the rendered view of a web page. Has no effect on a plain text document.