@Override
public Object execute(Frame frame) {
RAny lhsVal = (RAny) lhs.execute(frame);
Object rowFromVal = rowFromExpr.execute(frame);
Object rowToVal = rowToExpr.execute(frame);
Object colFromVal = colFromExpr.execute(frame);
Object colToVal = colToExpr.execute(frame);
boolean dropVal =
dropExpr.executeLogical(frame)
!= RLogical.FALSE; // FIXME: what is the correct execution order of these args?
int exactVal = exactExpr.executeLogical(frame);
if (!(lhsVal instanceof RArray)) {
throw RError.getObjectNotSubsettable(ast, lhsVal.typeOf());
}
RArray array = (RArray) lhsVal;
try {
int rowFrom = extractLimit(rowFromVal); // zero-based
int rowTo = extractLimit(rowToVal);
int colFrom = extractLimit(colFromVal);
int colTo = extractLimit(colToVal);
int[] dim = array.dimensions();
if (dim == null || dim.length != 2) {
throw RError.getIncorrectDimensions(getAST());
}
int m = dim[0];
int n = dim[1];
int rowStep;
int rowSize;
if (rowFrom <= rowTo) {
rowStep = 1;
if (rowTo > m) {
throw new UnexpectedResultException(null);
}
rowSize = rowTo - rowFrom + 1;
} else {
rowStep = -1;
if (rowFrom > m) {
throw new UnexpectedResultException(null);
}
rowSize = rowFrom - rowTo + 1;
}
int colStep;
int colSize;
if (colFrom <= colTo) {
colStep = 1;
if (colTo > n) {
throw new UnexpectedResultException(null);
}
colSize = colTo - colFrom + 1;
} else {
colStep = -1;
if (colFrom > n) {
throw new UnexpectedResultException(null);
}
colSize = colFrom - colTo + 1;
}
int[] ndim;
if (!dropVal || (rowSize > 1 && colSize > 1)) {
ndim = new int[] {rowSize, colSize};
} else {
ndim = null;
}
int size = rowSize * colSize;
RArray res = Utils.createArray(array, size, ndim, null, null); // drop attributes
if (colStep == 1 && rowStep == 1) {
int j = colFrom * m + rowFrom; // j - index to source matrix
int jmax = j + rowSize;
int jadvance = m - rowSize;
for (int i = 0; i < size; i++) {
res.set(i, array.getRef(j++)); // i - index to target matrix
if (j == jmax) {
j += jadvance;
jmax += m;
}
}
} else {
int i = 0;
// NOTE: here we know that colFrom != colTo and rowFrom != rowTo
for (int col = colFrom; col != colTo + colStep; col += colStep) {
for (int row = rowFrom; row != rowTo + rowStep; row += rowStep) {
res.set(i++, array.getRef(col * m + row));
}
}
}
return res;
} catch (UnexpectedResultException e) {
// FIXME: clean this up; does Colon need to be package-private?
ASTNode rowAST = rowFromExpr.getAST().getParent();
Builtin rowColon =
(Builtin)
Primitives.getCallFactory(RSymbol.getSymbol(":"), null)
.create(rowAST, rowFromExpr, rowToExpr);
SelectorNode selIExpr = Selector.createSelectorNode(rowAST, true, rowColon);
ASTNode colAST = colFromExpr.getAST().getParent();
Builtin colColon =
(Builtin)
Primitives.getCallFactory(RSymbol.getSymbol(":"), null)
.create(colAST, colFromExpr, colToExpr);
SelectorNode selJExpr = Selector.createSelectorNode(ast, true, colColon);
MatrixRead nn = new MatrixRead(ast, true, lhs, selIExpr, selJExpr, dropExpr, exactExpr);
replace(nn, "install MatrixRead from MatrixSequenceSubset");
Selector selI =
selIExpr.executeSelector(
rowColon.doBuiltIn(frame, new RAny[] {(RAny) rowFromVal, (RAny) rowToVal}));
Selector selJ =
selJExpr.executeSelector(
colColon.doBuiltIn(frame, new RAny[] {(RAny) colFromVal, (RAny) colToVal}));
return nn.executeLoop(array, selI, selJ, dropVal, exactVal);
}
}