[06 - Top Down Parser] Attempt to fix "program11Expr" tests

This commit is contained in:
2020-05-13 11:25:35 +02:00
parent a5c7c095a7
commit ccb3ac17ca
2 changed files with 49 additions and 6 deletions

View File

@@ -138,7 +138,7 @@ public class XParser {
if ((id = parseToken(Token.ID)) != null
&& (assign = parseToken(Token.ASSIGN)) != null
&& (numExpr = parseNumExpr()) != null) {
&& (numExpr = parseNumExpr0()) != null) {
tree.addLastChild(id);
tree.addLastChild(assign);
tree.addLastChild(numExpr);
@@ -149,15 +149,47 @@ public class XParser {
return null;
}
private Tree parseNumExpr() {
private Tree parseNumExpr0() {
int oldPosition = in.getPosition();
Tree tree = new Tree(new Token(Token.EXPR));
Tree intConst;
Tree intConst, a, operator, b;
if ((intConst = parseNumExpr2()) != null) {
tree.addLastChild(intConst);
return tree;
}
in.setPosition(oldPosition);
if (((a = parseNumExpr2()) != null)
&& ((operator = parseToken(Token.MULT)) != null
|| ((operator = parseToken(Token.DIV)) != null
|| ((operator = parseToken(Token.PLUS)) != null
|| ((operator = parseToken(Token.MINUS)) != null))))
&& ((b = parseNumExpr()) != null)) {
tree.addLastChild(a);
tree.addLastChild(operator);
tree.addLastChild(b);
return tree;
}
in.setPosition(oldPosition);
return null;
}
private Tree parseNumExpr() {
int oldPosition = in.getPosition();
Tree tree = new Tree(new Token(Token.EXPR));
Tree id, intConst;
if ((intConst = parseNumExpr2()) != null) {
tree.addLastChild(intConst);
return tree;
}
if ((id = parseToken(Token.ID)) != null) {
tree.addLastChild(id);
return tree;
}
in.setPosition(oldPosition);
return null;
@@ -166,13 +198,18 @@ public class XParser {
private Tree parseNumExpr2() {
int oldPosition = in.getPosition();
Tree tree = new Tree(new Token(Token.EXPR2));
Tree intConst;
Tree id, intConst;
if ((intConst = parseNumExpr3()) != null) {
tree.addLastChild(intConst);
return tree;
}
in.setPosition(oldPosition);
if ((id = parseToken(Token.ID)) != null) {
tree.addLastChild(id);
return tree;
}
in.setPosition(oldPosition);
return null;
}
@@ -180,12 +217,18 @@ public class XParser {
private Tree parseNumExpr3() {
int oldPosition = in.getPosition();
Tree tree = new Tree(new Token(Token.EXPR3));
Tree intConst;
Tree id, intConst;
if ((intConst = parseToken(Token.INTCONST)) != null) {
tree.addLastChild(intConst);
return tree;
}
in.setPosition(oldPosition);
if ((id = parseToken(Token.ID)) != null) {
tree.addLastChild(id);
return tree;
}
in.setPosition(oldPosition);
return null;
@@ -194,7 +237,7 @@ public class XParser {
private Tree parseToken(int tokenType) {
int oldPosition = in.getPosition();
Token nextToken = in.nextToken();
System.out.println("parseToken> " + nextToken);
System.out.println("parseToken> " + nextToken + " = " + Token.getTypeName(tokenType));
if (nextToken.getType() == tokenType) {
return new Tree(nextToken);
} else {