net.sf.saffron.oj.xlat
Class InternalTranslator

java.lang.Object
  |
  +--net.sf.saffron.oj.xlat.InternalTranslator

Direct Known Subclasses:

AggInternalTranslator

class InternalTranslator

extends Object

Converts an Openjava expression into a row-expression.

For example, the filter expression emp.sal > 50 from select * from emp where emp.sal > 50 becomes $input0.sal > 50. And emp.deptno == dept.deptno becomes $input.$0.deptno == $input.$1.deptno.

Any queries are wrapped as InternalTranslator.RexQuery nodes. They will be expanded later.

See Also:

AggInternalTranslator

Nested Class Summary

(package private) static class

InternalTranslator.RexQuery Temporary holder for a scalar query which has not been translated yet.

Field Summary

(package private) SaffronRel[]	inputs
private static HashMap	mapUnaryOpToRex
protected QueryEnvironment	qenv
(package private) QueryInfo	queryInfo
protected JavaRexBuilder	rexBuilder

Constructor Summary

(package private)

InternalTranslator(QueryInfo queryInfo, SaffronRel[] inputs, JavaRexBuilder rexBuilder)

Method Summary

private SqlOperator	binaryOpToSql(int op) Translates an operator code from Openjava (BinaryExpression.DIVIDE et cetera) to row-expression.
private static HashMap	createBinaryMap()
private static HashMap	createUnaryMap()
RexNode	evaluateDown(BinaryExpression p)
RexNode	evaluateDown(ConditionalExpression p)
RexNode	evaluateDown(FieldAccess p)
private RexNode	evaluateDown(Literal literal)
RexNode	evaluateDown(MethodCall call)
RexNode	evaluateDown(UnaryExpression p)
RexNode	evaluateDown(Variable p)
Expression	evaluateUp(AliasedExpression p)
RexNode	go(ParseTree p)
(package private) QueryInfo.LookupResult	lookupExp(String name) Returns an expression with which to reference a from-list item.
private SqlOperator	translateFun(String name)
private RexKind	unaryOpToRex(int op) Translates an operator code from Openjava (UnaryExpression.BIT_NOT et cetera) to row-expression.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

queryInfo

QueryInfo queryInfo

inputs

SaffronRel[] inputs

rexBuilder

protected final JavaRexBuilder rexBuilder

qenv

protected final QueryEnvironment qenv

mapUnaryOpToRex

private static final HashMap mapUnaryOpToRex

Constructor Detail

InternalTranslator

InternalTranslator(QueryInfo queryInfo,
                   SaffronRel[] inputs,
                   JavaRexBuilder rexBuilder)

Method Detail

createUnaryMap

private static HashMap createUnaryMap()

createBinaryMap

private static HashMap createBinaryMap()

go

public RexNode go(ParseTree p)

evaluateDown

private RexNode evaluateDown(Literal literal)

evaluateDown

public RexNode evaluateDown(FieldAccess p)

evaluateDown

public RexNode evaluateDown(UnaryExpression p)

unaryOpToRex

private RexKind unaryOpToRex(int op)

Translates an operator code from Openjava (UnaryExpression.BIT_NOT et cetera) to row-expression.

binaryOpToSql

private SqlOperator binaryOpToSql(int op)

Translates an operator code from Openjava (BinaryExpression.DIVIDE et cetera) to row-expression.

evaluateDown

public RexNode evaluateDown(BinaryExpression p)

evaluateDown

public RexNode evaluateDown(ConditionalExpression p)

evaluateDown

public RexNode evaluateDown(MethodCall call)

translateFun

private SqlOperator translateFun(String name)

evaluateDown

public RexNode evaluateDown(Variable p)

evaluateUp

public Expression evaluateUp(AliasedExpression p)

lookupExp

QueryInfo.LookupResult lookupExp(String name)

Returns an expression with which to reference a from-list item.

Parameters:

name - the alias of the from item

Returns:

a Variable or FieldAccess