question: protected boolean matchWord ( ) { IDocument doc = fText . getDocument ( ) ; try { int pos = curPos ; char c ; while ( pos >= 0 ) { c = doc . getChar ( pos ) ; if ( ! Character . isJavaIdentifierPart ( c ) ) break ; -- pos ; } startPos = pos ; pos = curPos ; int length = doc . getLength ( ) ; while ( pos < length ) { c = doc . getChar ( pos ) ; if ( ! Character . isJavaIdentifierPart ( c ) ) break ; ++ pos ; } endPos = pos ; return true ; } catch ( BadLocationException x ) { log . debug ( x ) ; } return false ; }
target:  Attempts to determine and set the start (fStartPos) and end (fEndPos) of the word that was double-clicked.