@Override
public IExpr evaluate(final IAST ast) {
Validate.checkRange(ast, 3);
if (ast.size() == 3 && ast.get(2).isList() && ((IAST) ast.get(2)).size() == 4) {
IAST list = (IAST) ast.get(2);
if (ast.get(1).isPlus()) {
return ((IAST) ast.get(1)).map(Functors.replace1st(F.Sum(F.Null, ast.get(2))));
}
if (list.get(1).isSymbol() && list.get(2).isInteger() && list.get(3).isSymbol()) {
final ISymbol var = (ISymbol) list.get(1);
final IInteger from = (IInteger) list.get(2);
final ISymbol to = (ISymbol) list.get(3);
if (ast.get(1).isFree(var, true) && ast.get(1).isFree(to, true)) {
if (from.equals(F.C1)) {
return F.Times(to, ast.get(1));
}
if (from.equals(F.C0)) {
return F.Times(Plus(to, C1), ast.get(1));
}
} else {
if (ast.get(1).isTimes()) {
// Sum[ Times[a,b,c,...], {var, from, to} ]
IAST filterCollector = F.Times();
IAST restCollector = F.Times();
((IAST) ast.get(1))
.filter(
filterCollector,
restCollector,
new Predicate<IExpr>() {
@Override
public boolean apply(IExpr input) {
return input.isFree(var, true) && input.isFree(to, true);
}
});
if (filterCollector.size() > 1) {
if (restCollector.size() == 2) {
filterCollector.add(F.Sum(restCollector.get(1), ast.get(2)));
} else {
filterCollector.add(F.Sum(restCollector, ast.get(2)));
}
return filterCollector;
}
}
if (from.equals(F.C0)) {
IExpr repl =
ast.get(1).replaceAll(F.List(F.Rule(var, F.Slot(F.C1)), F.Rule(to, F.Slot(F.C2))));
if (repl != null) {
IExpr temp = MAP_0_N.get(repl);
if (temp != null) {
return temp.replaceAll(F.Rule(F.Slot(F.C1), to));
}
}
}
}
if (from.isPositive()) {
return F.Subtract(
F.Sum(ast.get(1), F.List(var, C0, to)),
F.Sum(ast.get(1), F.List(var, C0, from.minus(F.C1))));
}
}
}
IAST resultList = Plus();
IExpr temp = evaluateTable(ast, resultList, C0);
if (temp.equals(resultList)) {
return null;
}
return temp;
}
@Override
public void setUp(final ISymbol symbol) throws SyntaxError {
symbol.setAttributes(ISymbol.LISTABLE);
REPLACE_RULES = Functors.rules(REPLACE_STRINGS);
super.setUp(symbol);
}