setelem.java

用java实现的编译器. 包括语法分析

package inter;
import lexer.*;
import symbols.*;
public class SetElem extends Stmt {
	public Id array;
	public Expr index;
	public Expr expr;
	public SetElem(Access x, Expr y) {
		array = x.array;
		index = x;
		expr = y;
		if(check(x.type, expr.type) == null)
			error("type error");
	}
	public Type check(Type p1, Type p2) {
		if(p1 instanceof Array || p2 instanceof Array)
			return null;
		else if (p1 == p2) return p2;
		else if (Type.numeric(p1) && Type.numeric(p2))
			return p2;
		else return null;
	}
	public void gen(int b, int a) {
		String s1 = index.reduce().toString();
		String s2 = expr.reduce().toString();
		emit(array.toString() + "[" + s1 + "] = " + s2);
	}
}