@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); } }
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; }