48 lines
1.2 KiB
Java
48 lines
1.2 KiB
Java
/*
|
|
* Name: Mike Cifelli
|
|
* Course: CIS 443 - Programming Languages
|
|
* Assignment: Lisp Interpreter 1
|
|
*/
|
|
|
|
package eval;
|
|
|
|
import parser.*;
|
|
|
|
/**
|
|
* <code>QUOTE</code> represents the QUOTE form in Lisp.
|
|
*/
|
|
public class QUOTE extends LispFunction {
|
|
|
|
// The number of arguments that QUOTE takes.
|
|
private static final int NUM_ARGS = 1;
|
|
|
|
public SExpression call(Cons argList) {
|
|
// retrieve the number of arguments passed to QUOTE
|
|
int argListLength = LENGTH.getLength(argList);
|
|
|
|
// make sure we have received exactly one argument
|
|
if (argListLength != NUM_ARGS) {
|
|
Cons originalSExpr = new Cons(new Symbol("QUOTE"), argList);
|
|
String errMsg = "too " +
|
|
((argListLength > NUM_ARGS) ? "many" : "few") +
|
|
" arguments given to QUOTE: " + originalSExpr;
|
|
|
|
throw new RuntimeException(errMsg);
|
|
}
|
|
|
|
return argList.getCar();
|
|
}
|
|
|
|
/**
|
|
* Determine if the arguments passed to this Lisp function should be
|
|
* evaluated.
|
|
*
|
|
* @return
|
|
* <code>false</code>
|
|
*/
|
|
public boolean evaluateArguments() {
|
|
return false;
|
|
}
|
|
|
|
}
|