+InsetMath & Cursor::nextMath()
+{
+ return *nextAtom().nucleus();
+}
+
+
+InsetMath & Cursor::prevMath()
+{
+ return *prevAtom().nucleus();
+}
+
+
+bool Cursor::mathForward(bool word)
+{
+ LASSERT(inMathed(), return false);
+ if (pos() < lastpos()) {
+ if (word) {
+ // word: skip a group of insets of the form X*(B*|R*|P*) (greedy
+ // match) where X is any math class, B is mathbin, R is mathrel, and
+ // P is mathpunct. Make sure that the following remains true:
+ // mathForward(true); mathBackward(true); mathForward(true)
+ // is the same as mathForward(true) and
+ // mathBackward(true); mathForward(true); mathBackward(true)
+ // is the same as mathBackward(true).
+ MathClass mc = nextMath().mathClass();
+ do
+ posForward();
+ while (pos() < lastpos() && mc == nextMath().mathClass());
+ if (pos() < lastpos() &&
+ ((mc = nextMath().mathClass()) == MC_BIN ||
+ mc == MC_REL || mc == MC_PUNCT))
+ do
+ posForward();
+ while (pos() < lastpos() && mc == nextMath().mathClass());
+ } else if (openable(nextAtom())) {
+ // single step: try to enter the next inset
+ pushBackward(nextMath());
+ inset().idxFirst(*this);
+ } else
+ posForward();
+ return true;
+ }
+ if (inset().idxForward(*this))
+ return true;
+ // try to pop forwards --- but don't pop out of math! leave that to
+ // the FINISH lfuns
+ int s = depth() - 2;
+ if (s >= 0 && operator[](s).inset().asInsetMath())
+ return popForward();
+ return false;
+}
+
+
+bool Cursor::mathBackward(bool word)
+{
+ LASSERT(inMathed(), return false);
+ if (pos() > 0) {
+ if (word) {
+ // word: skip a group of insets. See the comment in mathForward.
+ MathClass mc = prevMath().mathClass();
+ do
+ posBackward();
+ while (pos() > 0 && mc == prevMath().mathClass());
+ if (pos() > 0 && (mc == MC_BIN || mc == MC_REL || mc == MC_PUNCT)) {
+ mc = prevMath().mathClass();
+ do
+ posBackward();
+ while (pos() > 0 && mc == prevMath().mathClass());
+ }
+ } else if (openable(prevAtom())) {
+ // single step: try to enter the preceding inset
+ posBackward();
+ push(nextMath());
+ inset().idxLast(*this);
+ } else
+ posBackward();
+ return true;
+ }
+ if (inset().idxBackward(*this))
+ return true;
+ // try to pop backwards --- but don't pop out of math! leave that to
+ // the FINISH lfuns
+ int s = depth() - 2;
+ if (s >= 0 && operator[](s).inset().asInsetMath())
+ return popBackward();
+ return false;
+}
+
+