@SuppressWarnings("unchecked")
private ConstraintConnectiveDescr parseExpression(
final RuleBuildContext context, final PatternDescr patternDescr, final String expression) {
DrlExprParser parser = new DrlExprParser(context.getConfiguration().getLanguageLevel());
ConstraintConnectiveDescr result = parser.parse(expression);
if (result == null || parser.hasErrors()) {
for (DroolsParserException error : parser.getErrors()) {
context.addError(
new DescrBuildError(
context.getParentDescr(),
patternDescr,
null,
"Unable to parser pattern expression:\n" + error.getMessage()));
}
return null;
}
return result;
}
@SuppressWarnings("unchecked")
private void processBinding(
RuleBuildContext context,
BaseDescr descr,
Declaration[] params,
List<Integer> declrIndexes,
List<Integer> varIndexes,
List<Object> arguments,
List<Declaration> requiredDeclarations,
InternalReadAccessor arrayReader,
Pattern pattern,
BindingDescr bind,
ConstraintConnectiveDescr result) {
Declaration declr =
context.getDeclarationResolver().getDeclaration(context.getRule(), bind.getVariable());
if (declr != null) {
// check right maps to a slot, otherwise we can't reverse this and should error
int pos = getPos(bind.getExpression(), params);
if (pos >= 0) {
// slot exist, reverse and continue
String slot = bind.getExpression();
String var = bind.getVariable();
bind.setVariable(slot);
bind.setExpression(var);
} else {
// else error, we cannot find the slot to unify against
}
}
// left does not already exist, is it a slot?
int pos = getPos(bind.getVariable(), params);
if (pos >= 0) {
// it's an input on a slot, is the input using bindings?
declr =
context.getDeclarationResolver().getDeclaration(context.getRule(), bind.getExpression());
if (declr != null) {
arguments.set(pos, declr);
declrIndexes.add(pos);
requiredDeclarations.add(declr);
} else {
// it must be a literal/expression
// it's an expression and thus an input
DrlExprParser parser = new DrlExprParser(context.getConfiguration().getLanguageLevel());
ConstraintConnectiveDescr bresult = parser.parse(bind.getExpression());
if (parser.hasErrors()) {
for (DroolsParserException error : parser.getErrors()) {
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
null,
"Unable to parser pattern expression:\n" + error.getMessage()));
}
return;
}
MVELDumper.MVELDumperContext mvelCtx = new MVELDumper.MVELDumperContext();
String expr = context.getCompilerFactory().getExpressionProcessor().dump(bresult, mvelCtx);
try {
Object o = MVEL.eval(expr);
arguments.set(pos, o); // for now we just work with literals
} catch (Exception e) {
context.addError(
new DescrBuildError(
context.getParentDescr(), descr, null, "Unable to compile expression:\n" + expr));
}
}
} else {
// this is creating a new output binding
// we know it doesn't exist, as we already checked for left == var
declr = pattern.addDeclaration(bind.getVariable());
pos = getPos(bind.getExpression(), params);
if (pos < 0) {
// error this must be a binding on a slot
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
null,
"named argument does not exist:\n" + bind.getExpression()));
return;
}
// this bit is different, notice its the ArrayElementReader that we wire up to, not the
// declaration.
ArrayElementReader reader =
new ArrayElementReader(arrayReader, pos, params[pos].getExtractor().getExtractToClass());
// Should the reader be registered like the others? Probably yes...
// PatternBuilder.registerReadAccessor( );
declr.setReadAccessor(reader);
varIndexes.add(pos);
arguments.set(pos, Variable.v);
}
}