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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.calcite.rex;
import org.apache.calcite.linq4j.function.Predicate1;
import org.apache.calcite.plan.RelOptPredicateList;
import org.apache.calcite.plan.RelOptUtil;
import org.apache.calcite.rel.RelCollation;
import org.apache.calcite.rel.RelCollations;
import org.apache.calcite.rel.RelFieldCollation;
import org.apache.calcite.rel.core.Filter;
import org.apache.calcite.rel.core.Join;
import org.apache.calcite.rel.core.Project;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.rel.type.RelDataTypeFamily;
import org.apache.calcite.rel.type.RelDataTypeField;
import org.apache.calcite.rex.RexTableInputRef.RelTableRef;
import org.apache.calcite.schema.Schemas;
import org.apache.calcite.sql.SqlAggFunction;
import org.apache.calcite.sql.SqlKind;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.fun.SqlStdOperatorTable;
import org.apache.calcite.sql.type.SqlTypeFamily;
import org.apache.calcite.sql.type.SqlTypeName;
import org.apache.calcite.sql.type.SqlTypeUtil;
import org.apache.calcite.sql.validate.SqlValidatorUtil;
import org.apache.calcite.util.ControlFlowException;
import org.apache.calcite.util.Litmus;
import org.apache.calcite.util.Pair;
import org.apache.calcite.util.Util;
import org.apache.calcite.util.mapping.Mappings;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.Predicate;
import javax.annotation.Nonnull;
/**
* Utility methods concerning row-expressions.
*/
public class RexUtil {
/** Executor for a bit of constant reduction. The user can pass in another executor. */
public static final RexExecutor EXECUTOR =
new RexExecutorImpl(Schemas.createDataContext(null, null));
private RexUtil() {
}
//~ Methods ----------------------------------------------------------------
/**
* Returns a guess for the selectivity of an expression.
*
* @param exp expression of interest, or null for none (implying a
* selectivity of 1.0)
* @return guessed selectivity
*/
public static double getSelectivity(RexNode exp) {
if ((exp == null) || exp.isAlwaysTrue()) {
return 1d;
}
return 0.1d;
}
/**
* Generates a cast from one row type to another
*
* @param rexBuilder RexBuilder to use for constructing casts
* @param lhsRowType target row type
* @param rhsRowType source row type; fields must be 1-to-1 with lhsRowType,
* in same order
* @return cast expressions
*/
public static List generateCastExpressions(
RexBuilder rexBuilder,
RelDataType lhsRowType,
RelDataType rhsRowType) {
final List fieldList = rhsRowType.getFieldList();
int n = fieldList.size();
assert n == lhsRowType.getFieldCount()
: "field count: lhs [" + lhsRowType + "] rhs [" + rhsRowType + "]";
List rhsExps = new ArrayList<>();
for (RelDataTypeField field : fieldList) {
rhsExps.add(
rexBuilder.makeInputRef(field.getType(), field.getIndex()));
}
return generateCastExpressions(rexBuilder, lhsRowType, rhsExps);
}
/**
* Generates a cast for a row type.
*
* @param rexBuilder RexBuilder to use for constructing casts
* @param lhsRowType target row type
* @param rhsExps expressions to be cast
* @return cast expressions
*/
public static List generateCastExpressions(
RexBuilder rexBuilder,
RelDataType lhsRowType,
List rhsExps) {
List lhsFields = lhsRowType.getFieldList();
List castExps = new ArrayList<>();
for (Pair pair
: Pair.zip(lhsFields, rhsExps, true)) {
RelDataTypeField lhsField = pair.left;
RelDataType lhsType = lhsField.getType();
final RexNode rhsExp = pair.right;
RelDataType rhsType = rhsExp.getType();
if (lhsType.equals(rhsType)) {
castExps.add(rhsExp);
} else {
castExps.add(rexBuilder.makeCast(lhsType, rhsExp));
}
}
return castExps;
}
/**
* Returns whether a node represents the NULL value.
*
* Examples:
*
*
* - For {@link org.apache.calcite.rex.RexLiteral} Unknown, returns false.
*
- For
CAST(NULL AS type), returns true if
* allowCast is true, false otherwise.
* - For
CAST(CAST(NULL AS type) AS type)),
* returns false.
*
*/
public static boolean isNullLiteral(
RexNode node,
boolean allowCast) {
if (node instanceof RexLiteral) {
RexLiteral literal = (RexLiteral) node;
if (literal.getTypeName() == SqlTypeName.NULL) {
assert null == literal.getValue();
return true;
} else {
// We don't regard UNKNOWN -- SqlLiteral(null,Boolean) -- as
// NULL.
return false;
}
}
if (allowCast) {
if (node.isA(SqlKind.CAST)) {
RexCall call = (RexCall) node;
if (isNullLiteral(call.operands.get(0), false)) {
// node is "CAST(NULL as type)"
return true;
}
}
}
return false;
}
/**
* Returns whether a node represents the NULL value or a series of nested
* {@code CAST(NULL AS type)} calls. For example:
* isNull(CAST(CAST(NULL as INTEGER) AS VARCHAR(1)))
* returns {@code true}.
*/
public static boolean isNull(RexNode expr) {
switch (expr.getKind()) {
case LITERAL:
return ((RexLiteral) expr).getValue2() == null;
case CAST:
return isNull(((RexCall) expr).operands.get(0));
default:
return false;
}
}
/**
* Returns whether a node represents a literal.
*
* Examples:
*
*
* - For
CAST(literal AS type), returns true if
* allowCast is true, false otherwise.
* - For
CAST(CAST(literal AS type) AS type)),
* returns false.
*
*
* @param node The node, never null.
* @param allowCast whether to regard CAST(literal) as a literal
* @return Whether the node is a literal
*/
public static boolean isLiteral(RexNode node, boolean allowCast) {
assert node != null;
if (node.isA(SqlKind.LITERAL)) {
return true;
}
if (allowCast) {
if (node.isA(SqlKind.CAST)) {
RexCall call = (RexCall) node;
if (isLiteral(call.operands.get(0), false)) {
// node is "CAST(literal as type)"
return true;
}
}
}
return false;
}
/**
* Returns whether every expression in a list is a literal.
*
* @param expressionOperands list of expressions to check
* @return true if every expression from the specified list is literal.
*/
public static boolean allLiterals(List expressionOperands) {
for (RexNode rexNode : expressionOperands) {
if (!isLiteral(rexNode, true)) {
return false;
}
}
return true;
}
/**
* Returns whether a node represents an input reference or field access.
*
* @param node The node, never null.
* @param allowCast whether to regard CAST(x) as true
* @return Whether the node is a reference or access
*/
public static boolean isReferenceOrAccess(RexNode node, boolean allowCast) {
assert node != null;
if (node instanceof RexInputRef || node instanceof RexFieldAccess) {
return true;
}
if (allowCast) {
if (node.isA(SqlKind.CAST)) {
RexCall call = (RexCall) node;
return isReferenceOrAccess(call.operands.get(0), false);
}
}
return false;
}
/** Returns whether an expression is a cast just for the purposes of
* nullability, not changing any other aspect of the type. */
public static boolean isNullabilityCast(RelDataTypeFactory typeFactory,
RexNode node) {
switch (node.getKind()) {
case CAST:
final RexCall call = (RexCall) node;
final RexNode arg0 = call.getOperands().get(0);
return SqlTypeUtil.equalSansNullability(typeFactory, arg0.getType(),
call.getType());
}
return false;
}
/** Removes any casts that change nullability but not type.
*
* For example, {@code CAST(1 = 0 AS BOOLEAN)} becomes {@code 1 = 0}. */
public static RexNode removeNullabilityCast(RelDataTypeFactory typeFactory,
RexNode node) {
while (isNullabilityCast(typeFactory, node)) {
node = ((RexCall) node).operands.get(0);
}
return node;
}
/** Creates a map containing each (e, constant) pair that occurs within
* a predicate list.
*
* @param clazz Class of expression that is considered constant
* @param rexBuilder Rex builder
* @param predicates Predicate list
* @param what to consider a constant: {@link RexLiteral} to use a narrow
* definition of constant, or {@link RexNode} to use
* {@link RexUtil#isConstant(RexNode)}
* @return Map from values to constants
*/
public static ImmutableMap predicateConstants(
Class clazz, RexBuilder rexBuilder, List predicates) {
// We cannot use an ImmutableMap.Builder here. If there are multiple entries
// with the same key (e.g. "WHERE deptno = 1 AND deptno = 2"), it doesn't
// matter which we take, so the latter will replace the former.
// The basic idea is to find all the pairs of RexNode = RexLiteral
// (1) If 'predicates' contain a non-EQUALS, we bail out.
// (2) It is OK if a RexNode is equal to the same RexLiteral several times,
// (e.g. "WHERE deptno = 1 AND deptno = 1")
// (3) It will return false if there are inconsistent constraints (e.g.
// "WHERE deptno = 1 AND deptno = 2")
final Map map = new HashMap<>();
final Set excludeSet = new HashSet<>();
for (RexNode predicate : predicates) {
gatherConstraints(clazz, predicate, map, excludeSet, rexBuilder);
}
final ImmutableMap.Builder builder =
ImmutableMap.builder();
for (Map.Entry entry : map.entrySet()) {
RexNode rexNode = entry.getKey();
if (!overlap(rexNode, excludeSet)) {
builder.put(rexNode, entry.getValue());
}
}
return builder.build();
}
private static boolean overlap(RexNode rexNode, Set set) {
if (rexNode instanceof RexCall) {
for (RexNode r : ((RexCall) rexNode).getOperands()) {
if (overlap(r, set)) {
return true;
}
}
return false;
} else {
return set.contains(rexNode);
}
}
/** Tries to decompose the RexNode which is a RexCall into non-literal
* RexNodes. */
private static void decompose(Set set, RexNode rexNode) {
if (rexNode instanceof RexCall) {
for (RexNode r : ((RexCall) rexNode).getOperands()) {
decompose(set, r);
}
} else if (!(rexNode instanceof RexLiteral)) {
set.add(rexNode);
}
}
private static void gatherConstraints(Class clazz,
RexNode predicate, Map map, Set excludeSet,
RexBuilder rexBuilder) {
if (predicate.getKind() != SqlKind.EQUALS
&& predicate.getKind() != SqlKind.IS_NULL) {
decompose(excludeSet, predicate);
return;
}
final List operands = ((RexCall) predicate).getOperands();
if (operands.size() != 2 && predicate.getKind() == SqlKind.EQUALS) {
decompose(excludeSet, predicate);
return;
}
// if it reaches here, we have rexNode equals rexNode
final RexNode left;
final RexNode right;
if (predicate.getKind() == SqlKind.EQUALS) {
left = operands.get(0);
right = operands.get(1);
} else {
left = operands.get(0);
right = rexBuilder.makeNullLiteral(left.getType());
}
// Note that literals are immutable too, and they can only be compared
// through values.
gatherConstraint(clazz, left, right, map, excludeSet, rexBuilder);
gatherConstraint(clazz, right, left, map, excludeSet, rexBuilder);
}
private static void gatherConstraint(Class clazz,
RexNode left, RexNode right, Map map, Set excludeSet,
RexBuilder rexBuilder) {
if (!clazz.isInstance(right)) {
return;
}
if (!isConstant(right)) {
return;
}
C constant = clazz.cast(right);
if (excludeSet.contains(left)) {
return;
}
final C existedValue = map.get(left);
if (existedValue == null) {
switch (left.getKind()) {
case CAST:
// Convert "CAST(c) = literal" to "c = literal", as long as it is a
// widening cast.
final RexNode operand = ((RexCall) left).getOperands().get(0);
if (canAssignFrom(left.getType(), operand.getType())) {
final RexNode castRight =
rexBuilder.makeCast(operand.getType(), constant);
if (castRight instanceof RexLiteral) {
left = operand;
constant = clazz.cast(castRight);
}
}
}
map.put(left, constant);
} else {
if (existedValue instanceof RexLiteral
&& constant instanceof RexLiteral
&& !Objects.equals(((RexLiteral) existedValue).getValue(),
((RexLiteral) constant).getValue())) {
// we found conflicting values, e.g. left = 10 and left = 20
map.remove(left);
excludeSet.add(left);
}
}
}
/** Returns whether a value of {@code type2} can be assigned to a variable
* of {@code type1}.
*
* For example:
*
* - {@code canAssignFrom(BIGINT, TINYINT)} returns {@code true}
* - {@code canAssignFrom(TINYINT, BIGINT)} returns {@code false}
* - {@code canAssignFrom(BIGINT, VARCHAR)} returns {@code false}
*
*/
private static boolean canAssignFrom(RelDataType type1, RelDataType type2) {
final SqlTypeName name1 = type1.getSqlTypeName();
final SqlTypeName name2 = type2.getSqlTypeName();
if (name1.getFamily() == name2.getFamily()) {
switch (name1.getFamily()) {
case NUMERIC:
return name1.compareTo(name2) >= 0;
default:
return true;
}
}
return false;
}
/**
* Walks over an expression and determines whether it is constant.
*/
static class ConstantFinder implements RexVisitor {
static final ConstantFinder INSTANCE = new ConstantFinder();
public Boolean visitLiteral(RexLiteral literal) {
return true;
}
public Boolean visitInputRef(RexInputRef inputRef) {
return false;
}
public Boolean visitLocalRef(RexLocalRef localRef) {
return false;
}
public Boolean visitOver(RexOver over) {
return false;
}
public Boolean visitSubQuery(RexSubQuery subQuery) {
return false;
}
@Override public Boolean visitTableInputRef(RexTableInputRef ref) {
return false;
}
@Override public Boolean visitPatternFieldRef(RexPatternFieldRef fieldRef) {
return false;
}
public Boolean visitCorrelVariable(RexCorrelVariable correlVariable) {
// Correlating variables change when there is an internal restart.
// Not good enough for our purposes.
return false;
}
public Boolean visitDynamicParam(RexDynamicParam dynamicParam) {
// Dynamic parameters are constant WITHIN AN EXECUTION, so that's
// good enough.
return true;
}
public Boolean visitCall(RexCall call) {
// Constant if operator is deterministic and all operands are
// constant.
return call.getOperator().isDeterministic()
&& RexVisitorImpl.visitArrayAnd(this, call.getOperands());
}
public Boolean visitRangeRef(RexRangeRef rangeRef) {
return false;
}
public Boolean visitFieldAccess(RexFieldAccess fieldAccess) {
// ".FIELD" is constant iff "" is constant.
return fieldAccess.getReferenceExpr().accept(this);
}
}
/**
* Returns whether node is made up of constants.
*
* @param node Node to inspect
* @return true if node is made up of constants, false otherwise
*/
public static boolean isConstant(RexNode node) {
return node.accept(ConstantFinder.INSTANCE);
}
/**
* Returns whether a given expression is deterministic.
*
* @param e Expression
* @return true if tree result is deterministic, false otherwise
*/
public static boolean isDeterministic(RexNode e) {
try {
RexVisitor visitor =
new RexVisitorImpl(true) {
@Override public Void visitCall(RexCall call) {
if (!call.getOperator().isDeterministic()) {
throw Util.FoundOne.NULL;
}
return super.visitCall(call);
}
};
e.accept(visitor);
return true;
} catch (Util.FoundOne ex) {
Util.swallow(ex, null);
return false;
}
}
/**
* Returns whether a given expressions is deterministic.
*
* @param list Expression
* @return true if tree result is deterministic, false otherwise
*/
public static boolean isDeterministic(List list) {
for (RexNode e : list) {
if (!isDeterministic(e)) {
return false;
}
}
return true;
}
public static List retainDeterministic(List list) {
List conjuctions = new ArrayList<>();
for (RexNode x : list) {
if (isDeterministic(x)) {
conjuctions.add(x);
}
}
return conjuctions;
}
/**
* Returns whether a given node contains a RexCall with a specified operator
*
* @param operator Operator to look for
* @param node a RexNode tree
*/
public static RexCall findOperatorCall(
final SqlOperator operator,
RexNode node) {
try {
RexVisitor visitor =
new RexVisitorImpl(true) {
public Void visitCall(RexCall call) {
if (call.getOperator().equals(operator)) {
throw new Util.FoundOne(call);
}
return super.visitCall(call);
}
};
node.accept(visitor);
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (RexCall) e.getNode();
}
}
/**
* Returns whether a given tree contains any {link RexInputRef} nodes.
*
* @param node a RexNode tree
*/
public static boolean containsInputRef(
RexNode node) {
try {
RexVisitor visitor =
new RexVisitorImpl(true) {
public Void visitInputRef(RexInputRef inputRef) {
throw new Util.FoundOne(inputRef);
}
};
node.accept(visitor);
return false;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return true;
}
}
/**
* Returns whether a given tree contains any
* {@link org.apache.calcite.rex.RexFieldAccess} nodes.
*
* @param node a RexNode tree
*/
public static boolean containsFieldAccess(RexNode node) {
try {
RexVisitor visitor =
new RexVisitorImpl(true) {
public Void visitFieldAccess(RexFieldAccess fieldAccess) {
throw new Util.FoundOne(fieldAccess);
}
};
node.accept(visitor);
return false;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return true;
}
}
/**
* Determines whether a {@link RexCall} requires decimal expansion. It
* usually requires expansion if it has decimal operands.
*
* Exceptions to this rule are:
*
*
* - isNull doesn't require expansion
*
- It's okay to cast decimals to and from char types
*
- It's okay to cast nulls as decimals
*
- Casts require expansion if their return type is decimal
*
- Reinterpret casts can handle a decimal operand
*
*
* @param expr expression possibly in need of expansion
* @param recurse whether to check nested calls
* @return whether the expression requires expansion
*/
public static boolean requiresDecimalExpansion(
RexNode expr,
boolean recurse) {
if (!(expr instanceof RexCall)) {
return false;
}
RexCall call = (RexCall) expr;
boolean localCheck = true;
switch (call.getKind()) {
case REINTERPRET:
case IS_NULL:
localCheck = false;
break;
case CAST:
RelDataType lhsType = call.getType();
RelDataType rhsType = call.operands.get(0).getType();
if (rhsType.getSqlTypeName() == SqlTypeName.NULL) {
return false;
}
if (SqlTypeUtil.inCharFamily(lhsType)
|| SqlTypeUtil.inCharFamily(rhsType)) {
localCheck = false;
} else if (SqlTypeUtil.isDecimal(lhsType)
&& (lhsType != rhsType)) {
return true;
}
break;
default:
localCheck = call.getOperator().requiresDecimalExpansion();
}
if (localCheck) {
if (SqlTypeUtil.isDecimal(call.getType())) {
// NOTE jvs 27-Mar-2007: Depending on the type factory, the
// result of a division may be decimal, even though both inputs
// are integer.
return true;
}
for (int i = 0; i < call.operands.size(); i++) {
if (SqlTypeUtil.isDecimal(call.operands.get(i).getType())) {
return true;
}
}
}
return recurse && requiresDecimalExpansion(call.operands, true);
}
/**
* Determines whether any operand of a set requires decimal expansion
*/
public static boolean requiresDecimalExpansion(
List operands,
boolean recurse) {
for (RexNode operand : operands) {
if (operand instanceof RexCall) {
RexCall call = (RexCall) operand;
if (requiresDecimalExpansion(call, recurse)) {
return true;
}
}
}
return false;
}
/**
* Returns whether a {@link RexProgram} contains expressions which require
* decimal expansion.
*/
public static boolean requiresDecimalExpansion(
RexProgram program,
boolean recurse) {
final List exprList = program.getExprList();
for (RexNode expr : exprList) {
if (requiresDecimalExpansion(expr, recurse)) {
return true;
}
}
return false;
}
public static boolean canReinterpretOverflow(RexCall call) {
assert call.isA(SqlKind.REINTERPRET) : "call is not a reinterpret";
return call.operands.size() > 1;
}
/**
* Returns whether an array of expressions has any common sub-expressions.
*/
public static boolean containNoCommonExprs(List exprs,
Litmus litmus) {
final ExpressionNormalizer visitor = new ExpressionNormalizer(false);
for (RexNode expr : exprs) {
try {
expr.accept(visitor);
} catch (ExpressionNormalizer.SubExprExistsException e) {
Util.swallow(e, null);
return litmus.fail(null);
}
}
return litmus.succeed();
}
/**
* Returns whether an array of expressions contains no forward references.
* That is, if expression #i contains a {@link RexInputRef} referencing
* field i or greater.
*
* @param exprs Array of expressions
* @param inputRowType Input row type
* @param litmus What to do if an error is detected (there is a
* forward reference)
*
* @return Whether there is a forward reference
*/
public static boolean containNoForwardRefs(List exprs,
RelDataType inputRowType,
Litmus litmus) {
final ForwardRefFinder visitor = new ForwardRefFinder(inputRowType);
for (int i = 0; i < exprs.size(); i++) {
RexNode expr = exprs.get(i);
visitor.setLimit(i); // field cannot refer to self or later field
try {
expr.accept(visitor);
} catch (ForwardRefFinder.IllegalForwardRefException e) {
Util.swallow(e, null);
return litmus.fail("illegal forward reference in {}", expr);
}
}
return litmus.succeed();
}
/**
* Returns whether an array of exp contains no aggregate function calls whose
* arguments are not {@link RexInputRef}s.
*
* @param exprs Expressions
* @param litmus Whether to assert if there is such a function call
*/
static boolean containNoNonTrivialAggs(List exprs, Litmus litmus) {
for (RexNode expr : exprs) {
if (expr instanceof RexCall) {
RexCall rexCall = (RexCall) expr;
if (rexCall.getOperator() instanceof SqlAggFunction) {
for (RexNode operand : rexCall.operands) {
if (!(operand instanceof RexLocalRef)
&& !(operand instanceof RexLiteral)) {
return litmus.fail("contains non trivial agg: {}", operand);
}
}
}
}
}
return litmus.succeed();
}
/**
* Returns whether a list of expressions contains complex expressions, that
* is, a call whose arguments are not {@link RexVariable} (or a subtype such
* as {@link RexInputRef}) or {@link RexLiteral}.
*/
public static boolean containComplexExprs(List exprs) {
for (RexNode expr : exprs) {
if (expr instanceof RexCall) {
for (RexNode operand : ((RexCall) expr).operands) {
if (!isAtomic(operand)) {
return true;
}
}
}
}
return false;
}
/**
* Returns whether any of the given expression trees contains a
* {link RexTableInputRef} node.
*
* @param nodes a list of RexNode trees
* @return true if at least one was found, otherwise false
*/
public static boolean containsTableInputRef(List nodes) {
for (RexNode e : nodes) {
if (containsTableInputRef(e) != null) {
return true;
}
}
return false;
}
/**
* Returns whether a given tree contains any {link RexTableInputRef} nodes.
*
* @param node a RexNode tree
* @return first such node found or null if it there is no such node
*/
public static RexTableInputRef containsTableInputRef(RexNode node) {
try {
RexVisitor visitor =
new RexVisitorImpl(true) {
public Void visitTableInputRef(RexTableInputRef inputRef) {
throw new Util.FoundOne(inputRef);
}
};
node.accept(visitor);
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (RexTableInputRef) e.getNode();
}
}
public static boolean isAtomic(RexNode expr) {
return (expr instanceof RexLiteral) || (expr instanceof RexVariable);
}
/**
* Returns whether a {@link RexNode node} is a {@link RexCall call} to a
* given {@link SqlOperator operator}.
*/
public static boolean isCallTo(RexNode expr, SqlOperator op) {
return (expr instanceof RexCall)
&& (((RexCall) expr).getOperator() == op);
}
/**
* Creates a record type with anonymous field names.
*
* @param typeFactory Type factory
* @param exprs Expressions
* @return Record type
*/
public static RelDataType createStructType(
RelDataTypeFactory typeFactory,
final List exprs) {
return createStructType(typeFactory, exprs, null, null);
}
/**
* Creates a record type with specified field names.
*
* The array of field names may be null, or any of the names within it
* can be null. We recommend using explicit names where possible, because it
* makes it much easier to figure out the intent of fields when looking at
* planner output.
*
* @param typeFactory Type factory
* @param exprs Expressions
* @param names Field names, may be null, or elements may be null
* @param suggester Generates alternative names if {@code names} is not
* null and its elements are not unique
* @return Record type
*/
public static RelDataType createStructType(
RelDataTypeFactory typeFactory,
final List exprs,
List names,
SqlValidatorUtil.Suggester suggester) {
if (names != null && suggester != null) {
names = SqlValidatorUtil.uniquify(names, suggester,
typeFactory.getTypeSystem().isSchemaCaseSensitive());
}
final RelDataTypeFactory.Builder builder = typeFactory.builder();
for (int i = 0; i < exprs.size(); i++) {
String name;
if (names == null || (name = names.get(i)) == null) {
name = "$f" + i;
}
builder.add(name, exprs.get(i).getType());
}
return builder.build();
}
@Deprecated // to be removed before 2.0
public static RelDataType createStructType(
RelDataTypeFactory typeFactory,
final List exprs,
List names) {
return createStructType(typeFactory, exprs, names, null);
}
/**
* Returns whether the type of an array of expressions is compatible with a
* struct type.
*
* @param exprs Array of expressions
* @param type Type
* @param litmus What to do if an error is detected (there is a mismatch)
*
* @return Whether every expression has the same type as the corresponding
* member of the struct type
*
* @see RelOptUtil#eq(String, RelDataType, String, RelDataType, org.apache.calcite.util.Litmus)
*/
public static boolean compatibleTypes(
List exprs,
RelDataType type,
Litmus litmus) {
final List fields = type.getFieldList();
if (exprs.size() != fields.size()) {
return litmus.fail("rowtype mismatches expressions");
}
for (int i = 0; i < fields.size(); i++) {
final RelDataType exprType = exprs.get(i).getType();
final RelDataType fieldType = fields.get(i).getType();
if (!RelOptUtil.eq("type1", exprType, "type2", fieldType, litmus)) {
return litmus.fail(null);
}
}
return litmus.succeed();
}
/**
* Creates a key for {@link RexNode} which is the same as another key of
* another RexNode only if the two have both the same type and textual
* representation. For example, "10" integer and "10" bigint result in
* different keys.
*/
public static Pair makeKey(RexNode expr) {
return Pair.of(expr.toString(), expr.getType().getFullTypeString());
}
/**
* Returns whether the leading edge of a given array of expressions is
* wholly {@link RexInputRef} objects with types corresponding to the
* underlying datatype.
*/
public static boolean containIdentity(
List exprs,
RelDataType rowType,
Litmus litmus) {
final List fields = rowType.getFieldList();
if (exprs.size() < fields.size()) {
return litmus.fail("exprs/rowType length mismatch");
}
for (int i = 0; i < fields.size(); i++) {
if (!(exprs.get(i) instanceof RexInputRef)) {
return litmus.fail("expr[{}] is not a RexInputRef", i);
}
RexInputRef inputRef = (RexInputRef) exprs.get(i);
if (inputRef.getIndex() != i) {
return litmus.fail("expr[{}] has ordinal {}", i, inputRef.getIndex());
}
if (!RelOptUtil.eq("type1",
exprs.get(i).getType(),
"type2",
fields.get(i).getType(), litmus)) {
return litmus.fail(null);
}
}
return litmus.succeed();
}
/** Returns whether a list of expressions projects the incoming fields. */
public static boolean isIdentity(List exps,
RelDataType inputRowType) {
return inputRowType.getFieldCount() == exps.size()
&& containIdentity(exps, inputRowType, Litmus.IGNORE);
}
/**
* Converts a collection of expressions into an AND.
* If there are zero expressions, returns TRUE.
* If there is one expression, returns just that expression.
* Removes expressions that always evaluate to TRUE.
* Returns null only if {@code nullOnEmpty} and expression is TRUE.
*/
public static RexNode composeConjunction(RexBuilder rexBuilder,
Iterable nodes, boolean nullOnEmpty) {
ImmutableList list = flattenAnd(nodes);
switch (list.size()) {
case 0:
return nullOnEmpty
? null
: rexBuilder.makeLiteral(true);
case 1:
return list.get(0);
default:
return rexBuilder.makeCall(SqlStdOperatorTable.AND, list);
}
}
/** Flattens a list of AND nodes.
*
* Treats null nodes as literal TRUE (i.e. ignores them). */
public static ImmutableList flattenAnd(
Iterable nodes) {
if (nodes instanceof Collection && ((Collection) nodes).isEmpty()) {
// Optimize common case
return ImmutableList.of();
}
final ImmutableList.Builder builder = ImmutableList.builder();
final Set digests = new HashSet<>(); // to eliminate duplicates
for (RexNode node : nodes) {
if (node != null) {
addAnd(builder, digests, node);
}
}
return builder.build();
}
private static void addAnd(ImmutableList.Builder builder,
Set digests, RexNode node) {
switch (node.getKind()) {
case AND:
for (RexNode operand : ((RexCall) node).getOperands()) {
addAnd(builder, digests, operand);
}
return;
default:
if (!node.isAlwaysTrue() && digests.add(node.toString())) {
builder.add(node);
}
}
}
/**
* Converts a collection of expressions into an OR.
* If there are zero expressions, returns FALSE.
* If there is one expression, returns just that expression.
* Removes expressions that always evaluate to FALSE.
* Flattens expressions that are ORs.
*/
@Nonnull public static RexNode composeDisjunction(RexBuilder rexBuilder,
Iterable nodes) {
final RexNode e = composeDisjunction(rexBuilder, nodes, false);
return Objects.requireNonNull(e);
}
/**
* Converts a collection of expressions into an OR,
* optionally returning null if the list is empty.
*/
public static RexNode composeDisjunction(RexBuilder rexBuilder,
Iterable nodes, boolean nullOnEmpty) {
ImmutableList list = flattenOr(nodes);
switch (list.size()) {
case 0:
return nullOnEmpty
? null
: rexBuilder.makeLiteral(false);
case 1:
return list.get(0);
default:
return rexBuilder.makeCall(SqlStdOperatorTable.OR, list);
}
}
/** Flattens a list of OR nodes. */
public static ImmutableList flattenOr(
Iterable nodes) {
if (nodes instanceof Collection && ((Collection) nodes).isEmpty()) {
// Optimize common case
return ImmutableList.of();
}
final ImmutableList.Builder builder = ImmutableList.builder();
final Set digests = new HashSet<>(); // to eliminate duplicates
for (RexNode node : nodes) {
addOr(builder, digests, node);
}
return builder.build();
}
private static void addOr(ImmutableList.Builder builder,
Set digests, RexNode node) {
switch (node.getKind()) {
case OR:
for (RexNode operand : ((RexCall) node).getOperands()) {
addOr(builder, digests, operand);
}
return;
default:
if (!node.isAlwaysFalse() && digests.add(node.toString())) {
builder.add(node);
}
}
}
/**
* Applies a mapping to a collation list.
*
* @param mapping Mapping
* @param collationList Collation list
* @return collation list with mapping applied to each field
*/
public static List apply(
Mappings.TargetMapping mapping,
List collationList) {
final List newCollationList = new ArrayList<>();
for (RelCollation collation : collationList) {
final List newFieldCollationList = new ArrayList<>();
for (RelFieldCollation fieldCollation
: collation.getFieldCollations()) {
final RelFieldCollation newFieldCollation =
apply(mapping, fieldCollation);
if (newFieldCollation == null) {
// This field is not mapped. Stop here. The leading edge
// of the collation is still valid (although it's useless
// if it's empty).
break;
}
newFieldCollationList.add(newFieldCollation);
}
// Truncation to collations to their leading edge creates empty
// and duplicate collations. Ignore these.
if (!newFieldCollationList.isEmpty()) {
final RelCollation newCollation =
RelCollations.of(newFieldCollationList);
if (!newCollationList.contains(newCollation)) {
newCollationList.add(newCollation);
}
}
}
// REVIEW: There might be redundant collations in the list. For example,
// in {(x), (x, y)}, (x) is redundant because it is a leading edge of
// another collation in the list. Could remove redundant collations.
return newCollationList;
}
/**
* Applies a mapping to a collation.
*
* @param mapping Mapping
* @param collation Collation
* @return collation with mapping applied
*/
public static RelCollation apply(
Mappings.TargetMapping mapping,
RelCollation collation) {
List fieldCollations =
applyFields(mapping, collation.getFieldCollations());
return fieldCollations.equals(collation.getFieldCollations())
? collation
: RelCollations.of(fieldCollations);
}
/**
* Applies a mapping to a field collation.
*
* If the field is not mapped, returns null.
*
* @param mapping Mapping
* @param fieldCollation Field collation
* @return collation with mapping applied
*/
public static RelFieldCollation apply(
Mappings.TargetMapping mapping,
RelFieldCollation fieldCollation) {
final int target =
mapping.getTargetOpt(fieldCollation.getFieldIndex());
if (target < 0) {
return null;
}
return fieldCollation.copy(target);
}
/**
* Applies a mapping to a list of field collations.
*
* @param mapping Mapping
* @param fieldCollations Field collations
* @return collations with mapping applied
*/
public static List applyFields(
Mappings.TargetMapping mapping,
List fieldCollations) {
final List newFieldCollations = new ArrayList<>();
for (RelFieldCollation fieldCollation : fieldCollations) {
newFieldCollations.add(apply(mapping, fieldCollation));
}
return newFieldCollations;
}
/**
* Applies a mapping to an expression.
*/
public static RexNode apply(Mappings.TargetMapping mapping, RexNode node) {
return node.accept(RexPermuteInputsShuttle.of(mapping));
}
/**
* Applies a mapping to an iterable over expressions.
*/
public static Iterable apply(Mappings.TargetMapping mapping,
Iterable nodes) {
final RexPermuteInputsShuttle shuttle = RexPermuteInputsShuttle.of(mapping);
return Iterables.transform(nodes, e -> e.accept(shuttle));
}
/**
* Applies a shuttle to an array of expressions. Creates a copy first.
*
* @param shuttle Shuttle
* @param exprs Array of expressions
*/
public static T[] apply(
RexVisitor shuttle,
T[] exprs) {
T[] newExprs = exprs.clone();
for (int i = 0; i < newExprs.length; i++) {
final RexNode expr = newExprs[i];
if (expr != null) {
newExprs[i] = expr.accept(shuttle);
}
}
return newExprs;
}
/**
* Applies a visitor to an array of expressions and, if specified, a single
* expression.
*
* @param visitor Visitor
* @param exprs Array of expressions
* @param expr Single expression, may be null
*/
public static void apply(
RexVisitor visitor,
RexNode[] exprs,
RexNode expr) {
for (RexNode e : exprs) {
e.accept(visitor);
}
if (expr != null) {
expr.accept(visitor);
}
}
/**
* Applies a visitor to a list of expressions and, if specified, a single
* expression.
*
* @param visitor Visitor
* @param exprs List of expressions
* @param expr Single expression, may be null
*/
public static void apply(
RexVisitor visitor,
List exprs,
RexNode expr) {
for (RexNode e : exprs) {
e.accept(visitor);
}
if (expr != null) {
expr.accept(visitor);
}
}
/** Flattens an expression.
*
* Returns the same expression if it is already flat. */
public static RexNode flatten(RexBuilder rexBuilder, RexNode node) {
if (node instanceof RexCall) {
RexCall call = (RexCall) node;
final SqlOperator op = call.getOperator();
final List flattenedOperands = flatten(call.getOperands(), op);
if (!isFlat(call.getOperands(), op)) {
return rexBuilder.makeCall(call.getType(), op, flattenedOperands);
}
}
return node;
}
/**
* Converts a list of operands into a list that is flat with respect to
* the given operator. The operands are assumed to be flat already.
*/
public static List flatten(List exprs,
SqlOperator op) {
if (isFlat(exprs, op)) {
//noinspection unchecked
return (List) exprs;
}
final List list = new ArrayList<>();
flattenRecurse(list, exprs, op);
return list;
}
/**
* Returns whether a call to {@code op} with {@code exprs} as arguments
* would be considered "flat".
*
* For example, {@code isFlat([w, AND[x, y], z, AND)} returns false;
*
{@code isFlat([w, x, y, z], AND)} returns true.
*/
private static boolean isFlat(
List exprs, final SqlOperator op) {
return !isAssociative(op)
|| !exists(exprs, (Predicate1) expr -> isCallTo(expr, op));
}
/**
* Returns false if the expression can be optimized by flattening
* calls to an associative operator such as AND and OR.
*/
public static boolean isFlat(RexNode expr) {
if (!(expr instanceof RexCall)) {
return true;
}
final RexCall call = (RexCall) expr;
return isFlat(call.getOperands(), call.getOperator())
&& all(call.getOperands(), RexUtil::isFlat);
}
private static void flattenRecurse(
List list, List exprs, SqlOperator op) {
for (RexNode expr : exprs) {
if (expr instanceof RexCall
&& ((RexCall) expr).getOperator() == op) {
flattenRecurse(list, ((RexCall) expr).getOperands(), op);
} else {
list.add(expr);
}
}
}
/**
* Returns whether the input is a 'loss-less' cast, that is, a cast from which
* the original value of the field can be certainly recovered.
*
* For instance, int → bigint is loss-less (as you can cast back to
* int without loss of information), but bigint → int is not loss-less.
*
*
The implementation of this method does not return false positives.
* However, it is not complete.
*/
public static boolean isLosslessCast(RexNode node) {
if (!node.isA(SqlKind.CAST)) {
return false;
}
final RelDataType source = ((RexCall) node).getOperands().get(0).getType();
final SqlTypeName sourceSqlTypeName = source.getSqlTypeName();
final RelDataType target = node.getType();
final SqlTypeName targetSqlTypeName = target.getSqlTypeName();
// 1) Both INT numeric types
if (SqlTypeFamily.INTEGER.getTypeNames().contains(sourceSqlTypeName)
&& SqlTypeFamily.INTEGER.getTypeNames().contains(targetSqlTypeName)) {
return targetSqlTypeName.compareTo(sourceSqlTypeName) >= 0;
}
// 2) Both CHARACTER types: it depends on the precision (length)
if (SqlTypeFamily.CHARACTER.getTypeNames().contains(sourceSqlTypeName)
&& SqlTypeFamily.CHARACTER.getTypeNames().contains(targetSqlTypeName)) {
return targetSqlTypeName.compareTo(sourceSqlTypeName) >= 0
&& source.getPrecision() <= target.getPrecision();
}
// 3) From NUMERIC family to CHARACTER family: it depends on the precision/scale
if (sourceSqlTypeName.getFamily() == SqlTypeFamily.NUMERIC
&& targetSqlTypeName.getFamily() == SqlTypeFamily.CHARACTER) {
int sourceLength = source.getPrecision() + 1; // include sign
if (source.getScale() != -1 && source.getScale() != 0) {
sourceLength += source.getScale() + 1; // include decimal mark
}
return target.getPrecision() >= sourceLength;
}
// Return FALSE by default
return false;
}
/** Converts an expression to conjunctive normal form (CNF).
*
*
The following expression is in CNF:
*
*
(a OR b) AND (c OR d)
*
* The following expression is not in CNF:
*
*
(a AND b) OR c
*
* but can be converted to CNF:
*
*
(a OR c) AND (b OR c)
*
* The following expression is not in CNF:
*
*
NOT (a OR NOT b)
*
* but can be converted to CNF by applying de Morgan's theorem:
*
*
NOT a AND b
*
* Expressions not involving AND, OR or NOT at the top level are in CNF.
*/
public static RexNode toCnf(RexBuilder rexBuilder, RexNode rex) {
return new CnfHelper(rexBuilder, -1).toCnf(rex);
}
/**
* Similar to {@link #toCnf(RexBuilder, RexNode)}; however, it lets you
* specify a threshold in the number of nodes that can be created out of
* the conversion.
*
*
If the number of resulting nodes exceeds that threshold,
* stops conversion and returns the original expression.
*
*
If the threshold is negative it is ignored.
*
*
Leaf nodes in the expression do not count towards the threshold.
*/
public static RexNode toCnf(RexBuilder rexBuilder, int maxCnfNodeCount,
RexNode rex) {
return new CnfHelper(rexBuilder, maxCnfNodeCount).toCnf(rex);
}
/** Converts an expression to disjunctive normal form (DNF).
*
*
DNF: It is a form of logical formula which is disjunction of conjunctive
* clauses.
*
*
All logical formulas can be converted into DNF.
*
*
The following expression is in DNF:
*
*
(a AND b) OR (c AND d)
*
* The following expression is not in CNF:
*
*
(a OR b) AND c
*
* but can be converted to DNF:
*
*
(a AND c) OR (b AND c)
*
* The following expression is not in CNF:
*
*
NOT (a OR NOT b)
*
* but can be converted to DNF by applying de Morgan's theorem:
*
*
NOT a AND b
*
* Expressions not involving AND, OR or NOT at the top level are in DNF.
*/
public static RexNode toDnf(RexBuilder rexBuilder, RexNode rex) {
return new DnfHelper(rexBuilder).toDnf(rex);
}
/**
* Returns whether an operator is associative. AND is associative,
* which means that "(x AND y) and z" is equivalent to "x AND (y AND z)".
* We might well flatten the tree, and write "AND(x, y, z)".
*/
private static boolean isAssociative(SqlOperator op) {
return op.getKind() == SqlKind.AND
|| op.getKind() == SqlKind.OR;
}
/**
* Returns whether there is an element in {@code list} for which
* {@code predicate} is true.
*/
public static boolean exists(
List list, Predicate1 predicate) {
for (E e : list) {
if (predicate.apply(e)) {
return true;
}
}
return false;
}
/**
* Returns whether {@code predicate} is true for all elements of
* {@code list}.
*/
public static boolean all(
List list, Predicate1 predicate) {
for (E e : list) {
if (!predicate.apply(e)) {
return false;
}
}
return true;
}
/**
* Shifts every {@link RexInputRef} in an expression by {@code offset}.
*/
public static RexNode shift(RexNode node, final int offset) {
if (offset == 0) {
return node;
}
return node.accept(new RexShiftShuttle(offset));
}
/**
* Shifts every {@link RexInputRef} in an expression by {@code offset}.
*/
public static Iterable shift(Iterable nodes, int offset) {
return new RexShiftShuttle(offset).apply(nodes);
}
/**
* Shifts every {@link RexInputRef} in an expression higher than {@code start}
* by {@code offset}.
*/
public static RexNode shift(RexNode node, final int start, final int offset) {
return node.accept(
new RexShuttle() {
@Override public RexNode visitInputRef(RexInputRef input) {
final int index = input.getIndex();
if (index < start) {
return input;
}
return new RexInputRef(index + offset, input.getType());
}
});
}
/** Creates an equivalent version of a node where common factors among ORs
* are pulled up.
*
* For example,
*
*
(a AND b) OR (a AND c AND d)
*
* becomes
*
*
a AND (b OR (c AND d))
*
* Note that this result is not in CNF
* (see {@link #toCnf(RexBuilder, RexNode)}) because there is an AND inside an
* OR.
*
*
This form is useful if, say, {@code a} contains columns from only the
* left-hand side of a join, and can be pushed to the left input.
*
* @param rexBuilder Rex builder
* @param node Expression to transform
* @return Equivalent expression with common factors pulled up
*/
public static RexNode pullFactors(RexBuilder rexBuilder, RexNode node) {
return new CnfHelper(rexBuilder, -1).pull(node);
}
@Deprecated // to be removed before 2.0
public static List fixUp(final RexBuilder rexBuilder,
List nodes, final RelDataType rowType) {
final List typeList = RelOptUtil.getFieldTypeList(rowType);
return fixUp(rexBuilder, nodes, typeList);
}
/** Fixes up the type of all {@link RexInputRef}s in an
* expression to match differences in nullability.
*
* Such differences in nullability occur when expressions are moved
* through outer joins.
*
*
Throws if there any greater inconsistencies of type. */
public static List fixUp(final RexBuilder rexBuilder,
List nodes, final List fieldTypes) {
return new FixNullabilityShuttle(rexBuilder, fieldTypes).apply(nodes);
}
/** Transforms a list of expressions into a list of their types. */
public static List types(List nodes) {
return Lists.transform(nodes, RexNode::getType);
}
public static List families(List types) {
return Lists.transform(types, RelDataType::getFamily);
}
/** Removes all expressions from a list that are equivalent to a given
* expression. Returns whether any were removed. */
public static boolean removeAll(List targets, RexNode e) {
int count = 0;
Iterator iterator = targets.iterator();
while (iterator.hasNext()) {
RexNode next = iterator.next();
if (eq(next, e)) {
++count;
iterator.remove();
}
}
return count > 0;
}
/** Returns whether two {@link RexNode}s are structurally equal.
*
* This method considers structure, not semantics. 'x < y' is not
* equivalent to 'y > x'.
*/
public static boolean eq(RexNode e1, RexNode e2) {
return e1 == e2 || e1.toString().equals(e2.toString());
}
/** Simplifies a boolean expression, always preserving its type and its
* nullability.
*
*
This is useful if you are simplifying expressions in a
* {@link Project}.
*
* @deprecated Use {@link RexSimplify#simplifyPreservingType(RexNode)},
* which allows you to specify an {@link RexExecutor}. */
@Deprecated // to be removed before 2.0
public static RexNode simplifyPreservingType(RexBuilder rexBuilder,
RexNode e) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, false,
EXECUTOR).simplifyPreservingType(e);
}
/**
* Simplifies a boolean expression, leaving UNKNOWN values as UNKNOWN, and
* using the default executor.
*
* @deprecated Use {@link RexSimplify#simplify(RexNode)},
* which allows you to specify an {@link RexExecutor}.
*/
@Deprecated // to be removed before 2.0
public static RexNode simplify(RexBuilder rexBuilder, RexNode e) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, false,
EXECUTOR).simplify(e);
}
/**
* Simplifies a boolean expression,
* using the default executor.
*
*
In particular:
*
* - {@code simplify(x = 1 AND y = 2 AND NOT x = 1)}
* returns {@code y = 2}
* - {@code simplify(x = 1 AND FALSE)}
* returns {@code FALSE}
*
*
* If the expression is a predicate in a WHERE clause, UNKNOWN values have
* the same effect as FALSE. In situations like this, specify
* {@code unknownAsFalse = true}, so and we can switch from 3-valued logic to
* simpler 2-valued logic and make more optimizations.
*
* @param rexBuilder Rex builder
* @param e Expression to simplify
* @param unknownAsFalse Whether to convert UNKNOWN values to FALSE
*
* @deprecated Use {@link RexSimplify#simplify(RexNode)},
* which allows you to specify an {@link RexExecutor}.
*/
@Deprecated // to be removed before 2.0
public static RexNode simplify(RexBuilder rexBuilder, RexNode e,
boolean unknownAsFalse) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY,
unknownAsFalse, EXECUTOR).simplify(e);
}
/**
* Simplifies a conjunction of boolean expressions.
*
* @deprecated Use {@link RexSimplify#simplifyAnds(Iterable)},
* which allows you to specify an {@link RexExecutor}.
*/
@Deprecated // to be removed before 2.0
public static RexNode simplifyAnds(RexBuilder rexBuilder,
Iterable nodes) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, false,
EXECUTOR).simplifyAnds(nodes);
}
@Deprecated // to be removed before 2.0
public static RexNode simplifyAnds(RexBuilder rexBuilder,
Iterable nodes, boolean unknownAsFalse) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY,
unknownAsFalse, EXECUTOR).simplifyAnds(nodes);
}
/** Negates a logical expression by adding or removing a NOT. */
public static RexNode not(RexNode e) {
switch (e.getKind()) {
case NOT:
return ((RexCall) e).getOperands().get(0);
default:
return addNot(e);
}
}
private static RexNode addNot(RexNode e) {
return new RexCall(e.getType(), SqlStdOperatorTable.NOT,
ImmutableList.of(e));
}
static SqlOperator op(SqlKind kind) {
switch (kind) {
case IS_FALSE:
return SqlStdOperatorTable.IS_FALSE;
case IS_TRUE:
return SqlStdOperatorTable.IS_TRUE;
case IS_UNKNOWN:
return SqlStdOperatorTable.IS_UNKNOWN;
case IS_NULL:
return SqlStdOperatorTable.IS_NULL;
case IS_NOT_FALSE:
return SqlStdOperatorTable.IS_NOT_FALSE;
case IS_NOT_TRUE:
return SqlStdOperatorTable.IS_NOT_TRUE;
case IS_NOT_NULL:
return SqlStdOperatorTable.IS_NOT_NULL;
case EQUALS:
return SqlStdOperatorTable.EQUALS;
case NOT_EQUALS:
return SqlStdOperatorTable.NOT_EQUALS;
case LESS_THAN:
return SqlStdOperatorTable.LESS_THAN;
case GREATER_THAN:
return SqlStdOperatorTable.GREATER_THAN;
case LESS_THAN_OR_EQUAL:
return SqlStdOperatorTable.LESS_THAN_OR_EQUAL;
case GREATER_THAN_OR_EQUAL:
return SqlStdOperatorTable.GREATER_THAN_OR_EQUAL;
default:
throw new AssertionError(kind);
}
}
@Deprecated // to be removed before 2.0
public static RexNode simplifyAnd(RexBuilder rexBuilder, RexCall e,
boolean unknownAsFalse) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY,
unknownAsFalse, EXECUTOR).simplifyAnd(e);
}
@Deprecated // to be removed before 2.0
public static RexNode simplifyAnd2(RexBuilder rexBuilder,
List terms, List notTerms) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, false,
EXECUTOR).simplifyAnd2(terms, notTerms);
}
@Deprecated // to be removed before 2.0
public static RexNode simplifyAnd2ForUnknownAsFalse(RexBuilder rexBuilder,
List terms, List notTerms) {
final Class clazz = Comparable.class;
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, true,
EXECUTOR).simplifyAnd2ForUnknownAsFalse(terms, notTerms);
}
public static RexNode negate(RexBuilder rexBuilder, RexCall call) {
switch (call.getKind()) {
case EQUALS:
case NOT_EQUALS:
case LESS_THAN:
case GREATER_THAN:
case LESS_THAN_OR_EQUAL:
case GREATER_THAN_OR_EQUAL:
final SqlOperator op = op(call.getKind().negateNullSafe());
return rexBuilder.makeCall(op, call.getOperands());
}
return null;
}
public static RexNode invert(RexBuilder rexBuilder, RexCall call) {
switch (call.getKind()) {
case EQUALS:
case NOT_EQUALS:
case LESS_THAN:
case GREATER_THAN:
case LESS_THAN_OR_EQUAL:
case GREATER_THAN_OR_EQUAL:
final SqlOperator op = op(call.getKind().reverse());
return rexBuilder.makeCall(op, Lists.reverse(call.getOperands()));
}
return null;
}
@Deprecated // to be removed before 2.0
public static RexNode simplifyOr(RexBuilder rexBuilder, RexCall call) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, false,
EXECUTOR).simplifyOr(call);
}
@Deprecated // to be removed before 2.0
public static RexNode simplifyOrs(RexBuilder rexBuilder,
List terms) {
return new RexSimplify(rexBuilder, RelOptPredicateList.EMPTY, false,
EXECUTOR).simplifyOrs(terms);
}
/**
* Creates the expression {@code e1 AND NOT notTerm1 AND NOT notTerm2 ...}.
*/
public static RexNode andNot(RexBuilder rexBuilder, RexNode e,
RexNode... notTerms) {
return andNot(rexBuilder, e, Arrays.asList(notTerms));
}
/**
* Creates the expression {@code e1 AND NOT notTerm1 AND NOT notTerm2 ...}.
*
* Examples:
*
* - andNot(p) returns "p"
*
- andNot(p, n1, n2) returns "p AND NOT n1 AND NOT n2"
*
- andNot(x = 10, x = 20, y = 30, x = 30)
* returns "x = 10 AND NOT (y = 30)"
*
*/
public static RexNode andNot(final RexBuilder rexBuilder, RexNode e,
Iterable notTerms) {
// If "e" is of the form "x = literal", remove all "x = otherLiteral"
// terms from notTerms.
switch (e.getKind()) {
case EQUALS:
final RexCall call = (RexCall) e;
if (call.getOperands().get(1) instanceof RexLiteral) {
notTerms = Util.filter(notTerms,
e2 -> {
switch (e2.getKind()) {
case EQUALS:
RexCall call2 = (RexCall) e2;
if (call2.getOperands().get(0)
.equals(call.getOperands().get(0))
&& call2.getOperands().get(1) instanceof RexLiteral) {
return false;
}
}
return true;
});
}
}
return composeConjunction(rexBuilder,
Iterables.concat(ImmutableList.of(e),
Iterables.transform(notTerms, e2 -> not(rexBuilder, e2))),
false);
}
/** Returns whether a given operand of a CASE expression is a predicate.
*
* A switched case (CASE x WHEN x1 THEN v1 ... ELSE e END) has an even
* number of arguments and odd-numbered arguments are predicates.
*
*
A condition case (CASE WHEN p1 THEN v1 ... ELSE e END) has an odd
* number of arguments and even-numbered arguments are predicates, except for
* the last argument. */
public static boolean isCasePredicate(RexCall call, int i) {
assert call.getKind() == SqlKind.CASE;
return i < call.operands.size() - 1
&& (call.operands.size() - i) % 2 == 1;
}
/** Returns a function that applies NOT to its argument.
*
* @deprecated Use {@link #not} */
@SuppressWarnings("Guava")
@Deprecated // to be removed in 2.0
public static com.google.common.base.Function notFn(
final RexBuilder rexBuilder) {
return e -> not(rexBuilder, e);
}
/** Applies NOT to an expression. */
static RexNode not(final RexBuilder rexBuilder, RexNode input) {
return input.isAlwaysTrue()
? rexBuilder.makeLiteral(false)
: input.isAlwaysFalse()
? rexBuilder.makeLiteral(true)
: input.getKind() == SqlKind.NOT
? ((RexCall) input).operands.get(0)
: rexBuilder.makeCall(SqlStdOperatorTable.NOT, input);
}
/** Returns whether an expression contains a {@link RexCorrelVariable}. */
public static boolean containsCorrelation(RexNode condition) {
try {
condition.accept(CorrelationFinder.INSTANCE);
return false;
} catch (Util.FoundOne e) {
return true;
}
}
/**
* Given an expression, it will swap the table references contained in its
* {@link RexTableInputRef} using the contents in the map.
*/
public static RexNode swapTableReferences(final RexBuilder rexBuilder,
final RexNode node, final Map tableMapping) {
return swapTableColumnReferences(rexBuilder, node, tableMapping, null);
}
/**
* Given an expression, it will swap its column references {@link RexTableInputRef}
* using the contents in the map (in particular, the first element of the set in the
* map value).
*/
public static RexNode swapColumnReferences(final RexBuilder rexBuilder,
final RexNode node, final Map> ec) {
return swapTableColumnReferences(rexBuilder, node, null, ec);
}
/**
* Given an expression, it will swap the table references contained in its
* {@link RexTableInputRef} using the contents in the first map, and then
* it will swap the column references {@link RexTableInputRef} using the contents
* in the second map (in particular, the first element of the set in the map value).
*/
public static RexNode swapTableColumnReferences(final RexBuilder rexBuilder,
final RexNode node, final Map tableMapping,
final Map> ec) {
RexShuttle visitor =
new RexShuttle() {
@Override public RexNode visitTableInputRef(RexTableInputRef inputRef) {
if (tableMapping != null) {
inputRef = RexTableInputRef.of(
tableMapping.get(inputRef.getTableRef()),
inputRef.getIndex(),
inputRef.getType());
}
if (ec != null) {
Set s = ec.get(inputRef);
if (s != null) {
inputRef = s.iterator().next();
}
}
return inputRef;
}
};
return visitor.apply(node);
}
/**
* Given an expression, it will swap the column references {@link RexTableInputRef}
* using the contents in the first map (in particular, the first element of the set
* in the map value), and then it will swap the table references contained in its
* {@link RexTableInputRef} using the contents in the second map.
*/
public static RexNode swapColumnTableReferences(final RexBuilder rexBuilder,
final RexNode node, final Map> ec,
final Map tableMapping) {
RexShuttle visitor =
new RexShuttle() {
@Override public RexNode visitTableInputRef(RexTableInputRef inputRef) {
if (ec != null) {
Set s = ec.get(inputRef);
if (s != null) {
inputRef = s.iterator().next();
}
}
if (tableMapping != null) {
inputRef = RexTableInputRef.of(
tableMapping.get(inputRef.getTableRef()),
inputRef.getIndex(),
inputRef.getType());
}
return inputRef;
}
};
return visitor.apply(node);
}
/**
* Gather all table references in input expressions.
*
* @param nodes expressions
* @return set of table references
*/
public static Set gatherTableReferences(final List nodes) {
final Set occurrences = new HashSet<>();
RexVisitor visitor =
new RexVisitorImpl(true) {
@Override public Void visitTableInputRef(RexTableInputRef ref) {
occurrences.add(ref.getTableRef());
return super.visitTableInputRef(ref);
}
};
for (RexNode e : nodes) {
e.accept(visitor);
}
return occurrences;
}
//~ Inner Classes ----------------------------------------------------------
/**
* Walks over expressions and builds a bank of common sub-expressions.
*/
private static class ExpressionNormalizer extends RexVisitorImpl {
final Map mapDigestToExpr = new HashMap<>();
final boolean allowDups;
protected ExpressionNormalizer(boolean allowDups) {
super(true);
this.allowDups = allowDups;
}
protected RexNode register(RexNode expr) {
final String key = expr.toString();
final RexNode previous = mapDigestToExpr.put(key, expr);
if (!allowDups && (previous != null)) {
throw new SubExprExistsException(expr);
}
return expr;
}
protected RexNode lookup(RexNode expr) {
return mapDigestToExpr.get(expr.toString());
}
public RexNode visitInputRef(RexInputRef inputRef) {
return register(inputRef);
}
public RexNode visitLiteral(RexLiteral literal) {
return register(literal);
}
public RexNode visitCorrelVariable(RexCorrelVariable correlVariable) {
return register(correlVariable);
}
public RexNode visitCall(RexCall call) {
List normalizedOperands = new ArrayList<>();
int diffCount = 0;
for (RexNode operand : call.getOperands()) {
operand.accept(this);
final RexNode normalizedOperand = lookup(operand);
normalizedOperands.add(normalizedOperand);
if (normalizedOperand != operand) {
++diffCount;
}
}
if (diffCount > 0) {
call =
call.clone(
call.getType(),
normalizedOperands);
}
return register(call);
}
public RexNode visitDynamicParam(RexDynamicParam dynamicParam) {
return register(dynamicParam);
}
public RexNode visitRangeRef(RexRangeRef rangeRef) {
return register(rangeRef);
}
public RexNode visitFieldAccess(RexFieldAccess fieldAccess) {
final RexNode expr = fieldAccess.getReferenceExpr();
expr.accept(this);
final RexNode normalizedExpr = lookup(expr);
if (normalizedExpr != expr) {
fieldAccess =
new RexFieldAccess(
normalizedExpr,
fieldAccess.getField());
}
return register(fieldAccess);
}
/**
* Thrown if there is a sub-expression.
*/
private static class SubExprExistsException extends ControlFlowException {
SubExprExistsException(RexNode expr) {
Util.discard(expr);
}
}
}
/**
* Walks over an expression and throws an exception if it finds an
* {@link RexInputRef} with an ordinal beyond the number of fields in the
* input row type, or a {@link RexLocalRef} with ordinal greater than that set
* using {@link #setLimit(int)}.
*/
private static class ForwardRefFinder extends RexVisitorImpl {
private int limit = -1;
private final RelDataType inputRowType;
ForwardRefFinder(RelDataType inputRowType) {
super(true);
this.inputRowType = inputRowType;
}
public Void visitInputRef(RexInputRef inputRef) {
super.visitInputRef(inputRef);
if (inputRef.getIndex() >= inputRowType.getFieldCount()) {
throw new IllegalForwardRefException();
}
return null;
}
public Void visitLocalRef(RexLocalRef inputRef) {
super.visitLocalRef(inputRef);
if (inputRef.getIndex() >= limit) {
throw new IllegalForwardRefException();
}
return null;
}
public void setLimit(int limit) {
this.limit = limit;
}
/** Thrown to abort a visit when we find an illegal forward reference.
* It changes control flow but is not considered an error. */
static class IllegalForwardRefException extends ControlFlowException {
}
}
/**
* Visitor which builds a bitmap of the inputs used by an expression.
*/
public static class FieldAccessFinder extends RexVisitorImpl {
private final List fieldAccessList;
public FieldAccessFinder() {
super(true);
fieldAccessList = new ArrayList<>();
}
public Void visitFieldAccess(RexFieldAccess fieldAccess) {
fieldAccessList.add(fieldAccess);
return null;
}
public Void visitCall(RexCall call) {
for (RexNode operand : call.operands) {
operand.accept(this);
}
return null;
}
public List getFieldAccessList() {
return fieldAccessList;
}
}
/** Helps {@link org.apache.calcite.rex.RexUtil#toCnf}. */
private static class CnfHelper {
final RexBuilder rexBuilder;
int currentCount;
final int maxNodeCount; // negative means no limit
private CnfHelper(RexBuilder rexBuilder, int maxNodeCount) {
this.rexBuilder = rexBuilder;
this.maxNodeCount = maxNodeCount;
}
public RexNode toCnf(RexNode rex) {
try {
this.currentCount = 0;
return toCnf2(rex);
} catch (OverflowError e) {
Util.swallow(e, null);
return rex;
}
}
private RexNode toCnf2(RexNode rex) {
final List operands;
switch (rex.getKind()) {
case AND:
incrementAndCheck();
operands = flattenAnd(((RexCall) rex).getOperands());
final List cnfOperands = new ArrayList<>();
for (RexNode node : operands) {
RexNode cnf = toCnf2(node);
switch (cnf.getKind()) {
case AND:
incrementAndCheck();
cnfOperands.addAll(((RexCall) cnf).getOperands());
break;
default:
incrementAndCheck();
cnfOperands.add(cnf);
}
}
return and(cnfOperands);
case OR:
incrementAndCheck();
operands = flattenOr(((RexCall) rex).getOperands());
final RexNode head = operands.get(0);
final RexNode headCnf = toCnf2(head);
final List headCnfs = RelOptUtil.conjunctions(headCnf);
final RexNode tail = or(Util.skip(operands));
final RexNode tailCnf = toCnf2(tail);
final List tailCnfs = RelOptUtil.conjunctions(tailCnf);
final List list = new ArrayList<>();
for (RexNode h : headCnfs) {
for (RexNode t : tailCnfs) {
list.add(or(ImmutableList.of(h, t)));
}
}
return and(list);
case NOT:
final RexNode arg = ((RexCall) rex).getOperands().get(0);
switch (arg.getKind()) {
case NOT:
return toCnf2(((RexCall) arg).getOperands().get(0));
case OR:
operands = ((RexCall) arg).getOperands();
return toCnf2(
and(Lists.transform(flattenOr(operands), RexUtil::addNot)));
case AND:
operands = ((RexCall) arg).getOperands();
return toCnf2(
or(Lists.transform(flattenAnd(operands), RexUtil::addNot)));
default:
incrementAndCheck();
return rex;
}
default:
incrementAndCheck();
return rex;
}
}
private void incrementAndCheck() {
if (maxNodeCount >= 0 && ++currentCount > maxNodeCount) {
throw OverflowError.INSTANCE;
}
}
/** Exception to catch when we pass the limit. */
@SuppressWarnings("serial")
private static class OverflowError extends ControlFlowException {
@SuppressWarnings("ThrowableInstanceNeverThrown")
protected static final OverflowError INSTANCE = new OverflowError();
private OverflowError() {}
}
private RexNode pull(RexNode rex) {
final List operands;
switch (rex.getKind()) {
case AND:
operands = flattenAnd(((RexCall) rex).getOperands());
return and(pullList(operands));
case OR:
operands = flattenOr(((RexCall) rex).getOperands());
final Map factors = commonFactors(operands);
if (factors.isEmpty()) {
return or(operands);
}
final List list = new ArrayList<>();
for (RexNode operand : operands) {
list.add(removeFactor(factors, operand));
}
return and(Iterables.concat(factors.values(), ImmutableList.of(or(list))));
default:
return rex;
}
}
private List pullList(List nodes) {
final List list = new ArrayList<>();
for (RexNode node : nodes) {
RexNode pulled = pull(node);
switch (pulled.getKind()) {
case AND:
list.addAll(((RexCall) pulled).getOperands());
break;
default:
list.add(pulled);
}
}
return list;
}
private Map commonFactors(List nodes) {
final Map map = new HashMap<>();
int i = 0;
for (RexNode node : nodes) {
if (i++ == 0) {
for (RexNode conjunction : RelOptUtil.conjunctions(node)) {
map.put(conjunction.toString(), conjunction);
}
} else {
map.keySet().retainAll(strings(RelOptUtil.conjunctions(node)));
}
}
return map;
}
private RexNode removeFactor(Map factors, RexNode node) {
List list = new ArrayList<>();
for (RexNode operand : RelOptUtil.conjunctions(node)) {
if (!factors.containsKey(operand.toString())) {
list.add(operand);
}
}
return and(list);
}
private RexNode and(Iterable nodes) {
return composeConjunction(rexBuilder, nodes, false);
}
private RexNode or(Iterable nodes) {
return composeDisjunction(rexBuilder, nodes);
}
}
/** Transforms a list of expressions to the list of digests. */
public static List strings(List list) {
return Lists.transform(list, Object::toString);
}
/** Helps {@link org.apache.calcite.rex.RexUtil#toDnf}. */
private static class DnfHelper {
final RexBuilder rexBuilder;
private DnfHelper(RexBuilder rexBuilder) {
this.rexBuilder = rexBuilder;
}
public RexNode toDnf(RexNode rex) {
final List operands;
switch (rex.getKind()) {
case AND:
operands = flattenAnd(((RexCall) rex).getOperands());
final RexNode head = operands.get(0);
final RexNode headDnf = toDnf(head);
final List headDnfs = RelOptUtil.disjunctions(headDnf);
final RexNode tail = and(Util.skip(operands));
final RexNode tailDnf = toDnf(tail);
final List tailDnfs = RelOptUtil.disjunctions(tailDnf);
final List list = new ArrayList<>();
for (RexNode h : headDnfs) {
for (RexNode t : tailDnfs) {
list.add(and(ImmutableList.of(h, t)));
}
}
return or(list);
case OR:
operands = flattenOr(((RexCall) rex).getOperands());
return or(toDnfs(operands));
case NOT:
final RexNode arg = ((RexCall) rex).getOperands().get(0);
switch (arg.getKind()) {
case NOT:
return toDnf(((RexCall) arg).getOperands().get(0));
case OR:
operands = ((RexCall) arg).getOperands();
return toDnf(
and(Lists.transform(flattenOr(operands), RexUtil::addNot)));
case AND:
operands = ((RexCall) arg).getOperands();
return toDnf(
or(Lists.transform(flattenAnd(operands), RexUtil::addNot)));
default:
return rex;
}
default:
return rex;
}
}
private List toDnfs(List nodes) {
final List list = new ArrayList<>();
for (RexNode node : nodes) {
RexNode dnf = toDnf(node);
switch (dnf.getKind()) {
case OR:
list.addAll(((RexCall) dnf).getOperands());
break;
default:
list.add(dnf);
}
}
return list;
}
private RexNode and(Iterable nodes) {
return composeConjunction(rexBuilder, nodes, false);
}
private RexNode or(Iterable nodes) {
return composeDisjunction(rexBuilder, nodes);
}
}
/** Shuttle that adds {@code offset} to each {@link RexInputRef} in an
* expression. */
private static class RexShiftShuttle extends RexShuttle {
private final int offset;
RexShiftShuttle(int offset) {
this.offset = offset;
}
@Override public RexNode visitInputRef(RexInputRef input) {
return new RexInputRef(input.getIndex() + offset, input.getType());
}
}
/** Visitor that throws {@link org.apache.calcite.util.Util.FoundOne} if
* applied to an expression that contains a {@link RexCorrelVariable}. */
private static class CorrelationFinder extends RexVisitorImpl {
static final CorrelationFinder INSTANCE = new CorrelationFinder();
private CorrelationFinder() {
super(true);
}
@Override public Void visitCorrelVariable(RexCorrelVariable var) {
throw Util.FoundOne.NULL;
}
}
/** Shuttle that fixes up an expression to match changes in nullability of
* input fields. */
public static class FixNullabilityShuttle extends RexShuttle {
private final List typeList;
private final RexBuilder rexBuilder;
public FixNullabilityShuttle(RexBuilder rexBuilder,
List typeList) {
this.typeList = typeList;
this.rexBuilder = rexBuilder;
}
@Override public RexNode visitInputRef(RexInputRef ref) {
final RelDataType rightType = typeList.get(ref.getIndex());
final RelDataType refType = ref.getType();
if (refType == rightType) {
return ref;
}
final RelDataType refType2 =
rexBuilder.getTypeFactory().createTypeWithNullability(refType,
rightType.isNullable());
if (refType2 == rightType) {
return new RexInputRef(ref.getIndex(), refType2);
}
throw new AssertionError("mismatched type " + ref + " " + rightType);
}
}
/** Visitor that throws {@link org.apache.calcite.util.Util.FoundOne} if
* applied to an expression that contains a {@link RexSubQuery}. */
public static class SubQueryFinder extends RexVisitorImpl {
public static final SubQueryFinder INSTANCE = new SubQueryFinder();
@SuppressWarnings("Guava")
@Deprecated // to be removed before 2.0
public static final com.google.common.base.Predicate PROJECT_PREDICATE =
SubQueryFinder::containsSubQuery;
@SuppressWarnings("Guava")
@Deprecated // to be removed before 2.0
public static final Predicate FILTER_PREDICATE =
SubQueryFinder::containsSubQuery;
@SuppressWarnings("Guava")
@Deprecated // to be removed before 2.0
public static final com.google.common.base.Predicate JOIN_PREDICATE =
SubQueryFinder::containsSubQuery;
private SubQueryFinder() {
super(true);
}
/** Returns whether a {@link Project} contains a sub-query. */
public static boolean containsSubQuery(Project project) {
for (RexNode node : project.getProjects()) {
try {
node.accept(INSTANCE);
} catch (Util.FoundOne e) {
return true;
}
}
return false;
}
/** Returns whether a {@link Filter} contains a sub-query. */
public static boolean containsSubQuery(Filter filter) {
try {
filter.getCondition().accept(INSTANCE);
return false;
} catch (Util.FoundOne e) {
return true;
}
}
/** Returns whether a {@link Join} contains a sub-query. */
public static boolean containsSubQuery(Join join) {
try {
join.getCondition().accept(INSTANCE);
return false;
} catch (Util.FoundOne e) {
return true;
}
}
@Override public Void visitSubQuery(RexSubQuery subQuery) {
throw new Util.FoundOne(subQuery);
}
public static RexSubQuery find(Iterable nodes) {
for (RexNode node : nodes) {
try {
node.accept(INSTANCE);
} catch (Util.FoundOne e) {
return (RexSubQuery) e.getNode();
}
}
return null;
}
public static RexSubQuery find(RexNode node) {
try {
node.accept(INSTANCE);
return null;
} catch (Util.FoundOne e) {
return (RexSubQuery) e.getNode();
}
}
}
/** Deep expressions simplifier. */
public static class ExprSimplifier extends RexShuttle {
private final RexSimplify simplify;
private final Map unknownAsFalseMap;
private final boolean matchNullability;
@Deprecated // to be removed before 2.0
public ExprSimplifier(RexSimplify simplify) {
this(simplify, true);
}
public ExprSimplifier(RexSimplify simplify, boolean matchNullability) {
this.simplify = simplify;
this.unknownAsFalseMap = new HashMap<>();
this.matchNullability = matchNullability;
}
@Override public RexNode visitCall(RexCall call) {
boolean unknownAsFalseCall = simplify.unknownAsFalse;
if (unknownAsFalseCall) {
switch (call.getKind()) {
case AND:
case CASE:
final Boolean b = this.unknownAsFalseMap.get(call);
if (b == null) {
// Top operator
unknownAsFalseCall = true;
} else {
unknownAsFalseCall = b;
}
break;
default:
unknownAsFalseCall = false;
}
for (RexNode operand : call.operands) {
this.unknownAsFalseMap.put(operand, unknownAsFalseCall);
}
}
RexNode node = super.visitCall(call);
RexNode simplifiedNode =
simplify.withUnknownAsFalse(unknownAsFalseCall)
.simplify(node);
if (node == simplifiedNode) {
return node;
}
if (simplifiedNode.getType().equals(call.getType())) {
return simplifiedNode;
}
return simplify.rexBuilder.makeCast(call.getType(), simplifiedNode, matchNullability);
}
}
}
// End RexUtil.java