transcendental-lisp/src/function/builtin/special/RECUR.java
2017-11-16 20:53:55 -05:00

55 lines
1.5 KiB
Java

package function.builtin.special;
import static function.builtin.EVAL.evalArgumentList;
import error.LispException;
import function.ArgumentValidator;
import function.FunctionNames;
import function.LispFunction;
import function.LispSpecialFunction;
import sexpression.Cons;
import sexpression.SExpression;
import table.ExecutionContext;
@FunctionNames({ "RECUR" })
public class RECUR extends LispSpecialFunction {
private ArgumentValidator argumentValidator;
private ExecutionContext executionContext;
public RECUR(String name) {
this.argumentValidator = new ArgumentValidator(name);
this.executionContext = ExecutionContext.getInstance();
}
@Override
public SExpression call(Cons argumentList) {
argumentValidator.validate(argumentList);
if (!executionContext.isInFunctionCall()) {
throw new RecurOutsideOfFunctionException();
}
LispFunction currentFunction = executionContext.getCurrentFunction();
Cons recurArguments = argumentList;
if (currentFunction.isArgumentListEvaluated())
recurArguments = evalArgumentList(argumentList);
executionContext.setRecur();
return recurArguments;
}
public static class RecurOutsideOfFunctionException extends LispException {
private static final long serialVersionUID = 1L;
@Override
public String getMessage() {
return "recur called outide of function";
}
}
}