/**
* Create a jump table for a SELECT node.
*
* @param node the SELECT node.
* @return the jump table.
*/
private HashMap<Object, ICodeNode> createJumpTable(ICodeNode node) {
HashMap<Object, ICodeNode> jumpTable = new HashMap<Object, ICodeNode>();
// Loop over children that are SELECT_BRANCH nodes.
ArrayList<ICodeNode> selectChildren = node.getChildren();
for (int i = 1; i < selectChildren.size(); ++i) {
ICodeNode branchNode = selectChildren.get(i);
ICodeNode constantsNode = branchNode.getChildren().get(0);
ICodeNode statementNode = branchNode.getChildren().get(1);
// Loop over the constants children of the branch's CONSTANTS_NODE.
ArrayList<ICodeNode> constantsList = constantsNode.getChildren();
for (ICodeNode constantNode : constantsList) {
// Create a jump table entry.
// Convert a single-character string constant to a character.
Object value = constantNode.getAttribute(VALUE);
if (constantNode.getType() == STRING_CONSTANT) {
value = ((String) value).charAt(0);
}
jumpTable.put(value, statementNode);
}
}
return jumpTable;
}
/**
* Parse a set.
*
* @param token the initial token.
* @return the root of the generated parse subtree.
* @throws Exception if an error occurred.
*/
private ICodeNode parseSet(Token token) throws Exception {
ICodeNode rootNode = ICodeFactory.createICodeNode(ICodeNodeTypeImpl.SET);
HashSet<Integer> values = new HashSet<>();
rootNode.setAttribute(VALUE, new HashSet<Integer>());
boolean isFinished = false;
while (token.getType() != RIGHT_BRACKET && token.getType() != ERROR && !isFinished) {
ICodeNode leftNode = parseSimpleExpression(token);
if (leftNode.getType() == INTEGER_CONSTANT
&& !values.add((Integer) leftNode.getAttribute(VALUE))) {
errorHandler.flag(token, NON_UNIQUE_MEMBERS, this);
}
token = currentToken();
switch ((PascalTokenType) token.getType()) {
case RIGHT_BRACKET:
rootNode.addChild(leftNode);
break;
case COMMA:
rootNode.addChild(leftNode);
token = nextToken(); // Consume the ,
if (token.getType() == COMMA) {
errorHandler.flag(token, EXTRA_COMMAS, this);
token = nextToken(); // Consume the extra ,
}
break;
case DOT_DOT:
token = nextToken(); // Consume the ..
if (token.getType() == COMMA) {
errorHandler.flag(token, INVALID_SUBRANGE, this);
token = nextToken(); // Consume the ,
rootNode.addChild(leftNode);
} else {
ICodeNode rightNode = parseSimpleExpression(token);
ICodeNode subrangeNode = ICodeFactory.createICodeNode(SUBRANGE);
subrangeNode.addChild(leftNode);
subrangeNode.addChild(rightNode);
rootNode.addChild(subrangeNode);
if (leftNode.getType() == INTEGER_CONSTANT && rightNode.getType() == INTEGER_CONSTANT) {
boolean duplicateFound = false;
Integer leftRange = (Integer) leftNode.getAttribute(VALUE) + 1;
Integer rightRange = (Integer) rightNode.getAttribute(VALUE);
while (leftRange <= rightRange) {
if (!values.add(leftRange++) && !duplicateFound) {
errorHandler.flag(token, NON_UNIQUE_MEMBERS, this);
duplicateFound = true;
}
}
}
token = currentToken();
if (token.getType() == COMMA) {
token = nextToken(); // Consume the ,
} else if (token.getType() != RIGHT_BRACKET) {
errorHandler.flag(token, MISSING_COMMA, this);
}
}
break;
case INTEGER:
errorHandler.flag(token, MISSING_COMMA, this);
break;
case SEMICOLON:
isFinished = true;
break;
default:
errorHandler.flag(token, UNEXPECTED_TOKEN, this);
break;
}
}
return rootNode;
}