package net.fortytwo.ripple.libs.string;
import net.fortytwo.flow.Sink;
import net.fortytwo.ripple.RippleException;
import net.fortytwo.ripple.model.ModelConnection;
import net.fortytwo.ripple.model.PrimitiveStackMapping;
import net.fortytwo.ripple.model.RippleList;
import net.fortytwo.ripple.model.RippleValue;
/**
* A primitive which consumes a string and two integer indexes, then
* produces the substring between the first index (inclusive) and the second
* index (exclusive).
*
* @author Joshua Shinavier (http://fortytwo.net)
*/
public class Substring extends PrimitiveStackMapping {
private static final String[] IDENTIFIERS = {
StringLibrary.NS_2013_03 + "substring",
StringLibrary.NS_2008_08 + "substring",
StringLibrary.NS_2007_08 + "substring"};
public String[] getIdentifiers() {
return IDENTIFIERS;
}
public Substring()
throws RippleException {
super();
}
public Parameter[] getParameters() {
return new Parameter[]{
new Parameter("s", null, true),
new Parameter("beginIndex", null, true),
new Parameter("endIndex", null, true)};
}
public String getComment() {
return "s beginIndex endIndex => s2 -- where s2 is the substring of s which begins" +
" at the specified beginIndex and extends to the character at index endIndex - 1";
}
public void apply(final RippleList arg,
final Sink<RippleList> solutions,
final ModelConnection mc) throws RippleException {
RippleList stack = arg;
int begin, end;
RippleValue s;
String result;
end = mc.toNumericValue(stack.getFirst()).intValue();
stack = stack.getRest();
begin = mc.toNumericValue(stack.getFirst()).intValue();
stack = stack.getRest();
s = stack.getFirst();
stack = stack.getRest();
try {
result = mc.toString(s).substring(begin, end);
solutions.put(
stack.push(StringLibrary.value(result, mc, s)));
} catch (IndexOutOfBoundsException e) {
// Silent fail.
}
}
}