74 lines
2.2 KiB
Java
Executable File
74 lines
2.2 KiB
Java
Executable File
package frontend.ast.exp;
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import frontend.ast.Node;
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import frontend.ast.NodeStack;
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import frontend.ast.SyntaxType;
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import frontend.lexer.TokenStream;
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import frontend.lexer.TokenType;
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import frontend.ast.token.TokenNode;
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import midend.symbol.SymbolManager;
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import error.Errors;
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public class AddExp extends Node {
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public AddExp(TokenStream ts) {
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super(SyntaxType.ADD_EXP, ts);
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}
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public void parse(Errors errors) {
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NodeStack stack = new NodeStack();
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while (true) {
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MulExp mep = new MulExp(this.ts);
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mep.parse(errors);
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stack.push(mep);
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if (isAddOp()) {
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stack.push(new TokenNode(ts)); // addop
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} else {
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break;
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}
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}
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if (stack.size() == 1) {
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this.addChild((MulExp) stack.pop());
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} else {
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AddExp temp = this;
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while (stack.size() > 1) {
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AddExp ae = new AddExp(this.ts);
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MulExp mep = (MulExp) stack.pop();
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TokenNode op = (TokenNode) stack.pop();
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temp.addChild(ae);
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temp.addChild(op);
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temp.addChild(mep);
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temp = ae;
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}
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temp.addChild((MulExp) stack.pop());
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}
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}
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public boolean isAddOp() {
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TokenType t = getCurrToken().getType();
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return t == TokenType.PLUS || t == TokenType.MINU;
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}
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public int getType() {
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if (getChildren().size() == 1) {
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return ((MulExp) getChild(0)).getType();
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} else {
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return ((AddExp) getChild(0)).getType()
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| ((MulExp) getChild(2)).getType();
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}
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}
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public int getValue() {
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if (getChild(0) instanceof MulExp) {
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return ((MulExp) getChild(0)).getValue();
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} else {
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int left = ((AddExp) getChild(0)).getValue();
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int right = ((MulExp) getChild(2)).getValue();
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if (((TokenNode) getChild(1)).getType() == TokenType.PLUS) {
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return left + right;
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} else {
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return left - right;
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}
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}
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}
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}
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