/*
* createGST and gstMATCH
*
* Methods to implement the GST-TILING methodology of matching strings.
*/
private GST createGST(int needleLength, String haystack) {
GST gst = new GST(haystack);
// Needs to be at least a third of the needle length to
// count as a match
gst.setMinimumTileLength((int) Math.ceil(needleLength / 3));
return gst;
}
// ## TextConstraint gstMatch
//
// Matches a constraint within passed content. Makes sure that
// the constraint text is found within the content, but in order to
// be a true match, it has to match in or near the same location as
// the original constraint
//
// Parameters:
//
// * primaryContent - String - content to find context within
//
// * originalConstraint - TextConstraint - object to test internal constraint against
private TextConstraint gstMatch(String primaryContent, TextConstraint originalConstraint)
throws NoMatchFoundException {
GST g = createGST(this.beforeContext.length(), primaryContent);
g.match(this.beforeContext);
if (g.getTiles().size() == 0) throw new Context.NoMatchFoundException();
int startMatch = -1;
int maxMatchIndex =
originalConstraint.getStartPos()
- (this.beforeContext.length() + (int) Math.ceil((this.beforeContext.length() / 3)));
int minMatchIndex =
originalConstraint.getStartPos()
- (int) Math.ceil(Math.ceil(this.beforeContext.length() / 3));
int i;
// go through each matched TILE and see
// if the match is close to our context
for (GSTTile item : g.getTiles()) {
i = item.getStart();
if (i > startMatch && i > minMatchIndex && i <= maxMatchIndex) {
startMatch = item.getStart();
}
}
// Check if no matches found
if (startMatch < 1) throw new Context.NoMatchFoundException();
minMatchIndex =
originalConstraint.getEndPos()
+ (this.afterContext.length() + (int) Math.ceil((this.beforeContext.length() / 3)));
maxMatchIndex = originalConstraint.getEndPos() + this.afterContext.length();
int endMatch = -1;
for (GSTTile item : g.getTiles()) {
i = item.getStart() + item.getLength();
if (i > endMatch && i > minMatchIndex && i <= maxMatchIndex) {
endMatch = item.getStart();
}
}
if (endMatch < 1) throw new Context.NoMatchFoundException();
return new TextConstraint(startMatch, endMatch);
}