private void processPositional(
RuleBuildContext context,
Query query,
Declaration[] params,
List<Integer> declrIndexes,
List<Integer> varIndexes,
List<Object> arguments,
List<Declaration> requiredDeclarations,
InternalReadAccessor arrayReader,
Pattern pattern,
BaseDescr base,
String expression,
ConstraintConnectiveDescr result) {
int position = ((ExprConstraintDescr) base).getPosition();
if (position >= arguments.size()) {
context.addError(
new DescrBuildError(
context.getParentDescr(),
base,
null,
"Unable to parse query '"
+ query.getName()
+ "', as postion "
+ (position - 1)
+ " for expression '"
+ expression
+ "' does not exist on query size "
+ arguments.size()));
return;
}
if (isVariable(expression)) {
// is this already bound?
Declaration declr = context.getDeclarationResolver().getDeclaration(query, expression);
if (declr != null) {
// it exists, so it's an input
arguments.set(position, declr);
declrIndexes.add(position);
requiredDeclarations.add(declr);
} else {
// it doesn't exist, so it's an output
arguments.set(position, Variable.v);
varIndexes.add(position);
declr = pattern.addDeclaration(expression);
// this bit is different, notice its the ArrayElementReader that we wire up to, not the
// declaration.
ArrayElementReader reader =
new ArrayElementReader(
arrayReader, position, params[position].getExtractor().getExtractToClass());
declr.setReadAccessor(reader);
}
} else {
// it's an expression and thus an input
MVELDumper.MVELDumperContext mvelCtx = new MVELDumper.MVELDumperContext();
String rewrittenExpr =
context.getCompilerFactory().getExpressionProcessor().dump(result, mvelCtx);
arguments.set(position, MVEL.eval(rewrittenExpr)); // for now we just work with literals
}
}
private Accumulator[] buildExternalFunctions(
final RuleBuildContext context,
final AccumulateDescr accumDescr,
MVELDialect dialect,
Map<String, Declaration> decls,
Map<String, Declaration> sourceOuterDeclr,
BoundIdentifiers boundIds,
boolean readLocalsFromTuple) {
Accumulator[] accumulators;
List<AccumulateFunctionCallDescr> functions = accumDescr.getFunctions();
accumulators = new Accumulator[functions.size()];
// creating the custom array reader
InternalReadAccessor arrayReader = new SelfReferenceClassFieldReader(Object[].class, "this");
int index = 0;
Pattern pattern = (Pattern) context.getDeclarationResolver().peekBuildStack();
for (AccumulateFunctionCallDescr func : functions) {
// build an external function executor
AccumulateFunction function =
context.getConfiguration().getAccumulateFunction(func.getFunction());
if (function == null) {
// might have been imported in the package
function =
context
.getKnowledgeBuilder()
.getPackage()
.getAccumulateFunctions()
.get(func.getFunction());
}
if (function == null) {
context.addError(
new DescrBuildError(
accumDescr,
context.getRuleDescr(),
null,
"Unknown accumulate function: '"
+ func.getFunction()
+ "' on rule '"
+ context.getRuleDescr().getName()
+ "'. All accumulate functions must be registered before building a resource."));
return null;
}
final AnalysisResult analysis =
dialect.analyzeExpression(
context,
accumDescr,
func.getParams().length > 0 ? func.getParams()[0] : "\"\"",
boundIds);
MVELCompilationUnit unit =
dialect.getMVELCompilationUnit(
func.getParams().length > 0 ? func.getParams()[0] : "\"\"",
analysis,
getUsedDeclarations(decls, analysis),
getUsedDeclarations(sourceOuterDeclr, analysis),
null,
context,
"drools",
KnowledgeHelper.class,
readLocalsFromTuple,
MVELCompilationUnit.Scope.CONSTRAINT);
accumulators[index] = new MVELAccumulatorFunctionExecutor(unit, function);
// if there is a binding, create the binding
if (func.getBind() != null) {
if (context
.getDeclarationResolver()
.isDuplicated(context.getRule(), func.getBind(), function.getResultType().getName())) {
if (!func.isUnification()) {
context.addError(
new DescrBuildError(
context.getParentDescr(),
accumDescr,
null,
"Duplicate declaration for variable '"
+ func.getBind()
+ "' in the rule '"
+ context.getRule().getName()
+ "'"));
} else {
Declaration inner =
context.getDeclarationResolver().getDeclaration(context.getRule(), func.getBind());
Constraint c =
new MvelConstraint(
Collections.singletonList(context.getPkg().getName()),
accumDescr.isMultiFunction()
? "this[ " + index + " ] == " + func.getBind()
: "this == " + func.getBind(),
new Declaration[] {inner},
null,
IndexUtil.ConstraintType.EQUAL,
context
.getDeclarationResolver()
.getDeclaration(context.getRule(), func.getBind()),
accumDescr.isMultiFunction()
? new ArrayElementReader(arrayReader, index, function.getResultType())
: new SelfReferenceClassFieldReader(function.getResultType(), "this"),
true);
((MutableTypeConstraint) c).setType(Constraint.ConstraintType.BETA);
pattern.addConstraint(c);
index++;
}
} else {
Declaration declr = pattern.addDeclaration(func.getBind());
if (accumDescr.isMultiFunction()) {
declr.setReadAccessor(
new ArrayElementReader(arrayReader, index, function.getResultType()));
} else {
declr.setReadAccessor(
new SelfReferenceClassFieldReader(function.getResultType(), "this"));
}
}
}
index++;
}
return accumulators;
}
@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);
}
}
public void setDeclaration(Declaration declaration) {
declaration.setReadAccessor(getReadAccessor());
this.declaration = declaration;
}