public RuleConditionElement build(RuleBuildContext context,
BaseDescr descr,
Pattern prefixPattern) {
PatternDescr patternDescr = (PatternDescr) descr;
Query query = (Query) context.getPkg().getRule( patternDescr.getObjectType() );
Declaration[] params = query.getParameters();
List<BaseDescr> args = (List<BaseDescr>) patternDescr.getDescrs();
List<Integer> declrIndexes = new ArrayList<Integer>();
List<Integer> varIndexes = new ArrayList<Integer>();
List<Object> arguments = new ArrayList<Object>();
List<Declaration> requiredDeclarations = new ArrayList<Declaration>();
ObjectType argsObjectType = new ClassObjectType( Object[].class );
InternalReadAccessor arrayReader = new SelfReferenceClassFieldReader(Object[].class, "this");
Pattern pattern = new Pattern( context.getNextPatternId(),
0,
argsObjectType,
null );
for ( int i = 0, length = args.size(); i < length; i++ ) {
BaseDescr arg = args.get( i );
if ( arg instanceof LiteralDescr ) {
arguments.add( ((LiteralDescr) arg).getValue() );
} else if ( arg instanceof VariableDescr ) {
String var = ((VariableDescr) arg).getIdentifier();
Declaration declr = context.getDeclarationResolver().getDeclaration( query,
var );
if ( declr != null ) {
// declaration
declrIndexes.add( i );
arguments.add( declr );
requiredDeclarations.add( declr );
} else {
// unification variable
declr = pattern.addDeclaration( var );
// this bit is different, notice its the ArrayElementReader that we wire up to, not the declaration.
ArrayElementReader reader = new ArrayElementReader( arrayReader,
varIndexes.size(),
params[i].getExtractor().getExtractToClass() );
declr.setReadAccessor( reader );
varIndexes.add( i );
arguments.add( new Variable() );
}
}
}
Declaration[] declrsArray = requiredDeclarations.toArray( new Declaration[requiredDeclarations.size()] );
int[] declrIndexArray = new int[declrIndexes.size()];
for( int i = 0; i < declrsArray.length; i++ ) {
declrIndexArray[i] = declrIndexes.get( i );
}
int[] varIndexesArray = new int[varIndexes.size()];
for( int i = 0; i < varIndexesArray.length; i++ ) {
varIndexesArray[i] = varIndexes.get( i );
}
return new QueryElement( pattern,
query.getName(),
arguments.toArray( new Object[arguments.size()] ),
declrsArray,
declrIndexArray,
varIndexesArray );
}