use of org.apache.camel.language.simple.ast.SimpleNode in project camel by apache.
the class SimplePredicateParser method createPredicates.
/**
* Creates the {@link Predicate}s from the AST nodes.
*
* @return the created {@link Predicate}s, is never <tt>null</tt>.
*/
private List<Predicate> createPredicates() {
List<Predicate> answer = new ArrayList<Predicate>();
for (SimpleNode node : nodes) {
Expression exp = node.createExpression(expression);
if (exp != null) {
Predicate predicate = ExpressionToPredicateAdapter.toPredicate(exp);
answer.add(predicate);
}
}
return answer;
}
use of org.apache.camel.language.simple.ast.SimpleNode in project camel by apache.
the class BaseSimpleParser method prepareUnaryExpressions.
/**
* Prepares unary expressions.
* <p/>
* This process prepares the unary expressions in the AST. This is done
* by linking the unary operator with the left hand side node,
* to have the AST graph updated and prepared properly.
* <p/>
* So when the AST node is later used to create the {@link org.apache.camel.Predicate}s
* or {@link org.apache.camel.Expression}s to be used by Camel then the AST graph
* has a linked and prepared graph of nodes which represent the input expression.
*/
protected void prepareUnaryExpressions() {
Stack<SimpleNode> stack = new Stack<SimpleNode>();
for (SimpleNode node : nodes) {
if (node instanceof UnaryExpression) {
UnaryExpression token = (UnaryExpression) node;
// remember the logical operator
String operator = token.getOperator().toString();
SimpleNode previous = stack.isEmpty() ? null : stack.pop();
if (previous == null) {
throw new SimpleParserException("Unary operator " + operator + " has no left hand side token", token.getToken().getIndex());
} else {
token.acceptLeft(previous);
}
}
stack.push(node);
}
// replace nodes from the stack
nodes.clear();
nodes.addAll(stack);
}
use of org.apache.camel.language.simple.ast.SimpleNode in project camel by apache.
the class SimplePredicateParser method createNode.
/**
* Creates a node from the given token
*
* @param token the token
* @param startSingle state of single quoted blocks
* @param startDouble state of double quoted blocks
* @param startFunction state of function blocks
* @return the created node, or <tt>null</tt> to let a default node be created instead.
*/
private SimpleNode createNode(SimpleToken token, AtomicBoolean startSingle, AtomicBoolean startDouble, AtomicBoolean startFunction) {
if (token.getType().isFunctionStart()) {
startFunction.set(true);
return new SimpleFunctionStart(token);
} else if (token.getType().isFunctionEnd()) {
startFunction.set(false);
return new SimpleFunctionEnd(token);
}
// as we want all the tokens to be literal instead
if (startFunction.get()) {
return null;
}
// okay so far we also want to support quotes
if (token.getType().isSingleQuote()) {
SimpleNode answer;
boolean start = startSingle.get();
if (!start) {
answer = new SingleQuoteStart(token);
} else {
answer = new SingleQuoteEnd(token);
}
// flip state on start/end flag
startSingle.set(!start);
return answer;
} else if (token.getType().isDoubleQuote()) {
SimpleNode answer;
boolean start = startDouble.get();
if (!start) {
answer = new DoubleQuoteStart(token);
} else {
answer = new DoubleQuoteEnd(token);
}
// flip state on start/end flag
startDouble.set(!start);
return answer;
}
// as we want to only support embedded functions and all other kinds to be literal tokens
if (startSingle.get() || startDouble.get()) {
return null;
}
// and the special null value as well
if (token.getType().isUnary()) {
return new UnaryExpression(token);
} else if (token.getType().isBinary()) {
return new BinaryExpression(token);
} else if (token.getType().isLogical()) {
return new LogicalExpression(token);
} else if (token.getType().isNullValue()) {
return new NullExpression(token);
}
// by returning null, we will let the parser determine what to do
return null;
}
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